Repository: certbot/certbot
Pull request: Refactor cli.py, splitting in it smaller submodules
This is the result of a student project. We probably won't work on this anymore but we still wanted to share our work! This answers issue #4081 

`cli.py` is now a package with smaller submodules.
We wrote a few unit tests but not for everything that was refactored. However the modules were already covered by higher level tests, therefore, the coverage is not bad in the end. There could be a new issue to write unit tests for the new submodules.

[Fixes #4081.]

Problem statement:
certbot/cli.py is too long
Probably the easiest approach is to put `HelpfulArgumentParser` and related classes/methods into their own file. We can then use the class in `cli.py`, but it doesn't have to also be defined there.

This also dramatically simplifies unit testing `HelpfulArgumentParser`.

Hints from issue discussion:
Hey, my university project team and I will start working on this. We might not do it completely but we'll share what we've done anyway!

Commit message: Merge branch 'master' into refactor-cli

Patch to review:
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3eea1923de2..703219318b2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,7 @@ Certbot adheres to [Semantic Versioning](https://semver.org/).
   `keyAuthorization` field but will temporarily retry the request with the
   field included if a `malformed` error is received. This fallback will be
   removed in version 0.34.0.
+* cli is now a package split in submodules instead of a whole module.
 
 ### Fixed
 
diff --git a/certbot/cli.py b/certbot/cli.py
deleted file mode 100644
index 39812451089..00000000000
--- a/certbot/cli.py
+++ /dev/null
@@ -1,1614 +0,0 @@
-"""Certbot command line argument & config processing."""
-# pylint: disable=too-many-lines
-from __future__ import print_function
-import argparse
-import copy
-import glob
-import logging
-import logging.handlers
-import os
-import sys
-
-import configargparse
-import six
-import zope.component
-import zope.interface
-
-from zope.interface import interfaces as zope_interfaces
-
-from acme import challenges
-# pylint: disable=unused-import, no-name-in-module
-from acme.magic_typing import Any, Dict, Optional
-# pylint: enable=unused-import, no-name-in-module
-
-import certbot
-
-from certbot import constants
-from certbot import crypto_util
-from certbot import errors
-from certbot import hooks
-from certbot import interfaces
-from certbot import util
-
-from certbot.display import util as display_util
-from certbot.plugins import disco as plugins_disco
-import certbot.plugins.enhancements as enhancements
-import certbot.plugins.selection as plugin_selection
-
-logger = logging.getLogger(__name__)
-
-# Global, to save us from a lot of argument passing within the scope of this module
-helpful_parser = None  # type: Optional[HelpfulArgumentParser]
-
-# For help strings, figure out how the user ran us.
-# When invoked from letsencrypt-auto, sys.argv[0] is something like:
-# "/home/user/.local/share/certbot/bin/certbot"
-# Note that this won't work if the user set VENV_PATH or XDG_DATA_HOME before
-# running letsencrypt-auto (and sudo stops us from seeing if they did), so it
-# should only be used for purposes where inability to detect letsencrypt-auto
-# fails safely
-
-LEAUTO = "letsencrypt-auto"
-if "CERTBOT_AUTO" in os.environ:
-    # if we're here, this is probably going to be certbot-auto, unless the
-    # user saved the script under a different name
-    LEAUTO = os.path.basename(os.environ["CERTBOT_AUTO"])
-
-old_path_fragment = os.path.join(".local", "share", "letsencrypt")
-new_path_prefix = os.path.abspath(os.path.join(os.sep, "opt",
-                                               "eff.org", "certbot", "venv"))
-if old_path_fragment in sys.argv[0] or sys.argv[0].startswith(new_path_prefix):
-    cli_command = LEAUTO
-else:
-    cli_command = "certbot"
-
-# Argparse's help formatting has a lot of unhelpful peculiarities, so we want
-# to replace as much of it as we can...
-
-# This is the stub to include in help generated by argparse
-SHORT_USAGE = """
-  {0} [SUBCOMMAND] [options] [-d DOMAIN] [-d DOMAIN] ...
-
-Certbot can obtain and install HTTPS/TLS/SSL certificates.  By default,
-it will attempt to use a webserver both for obtaining and installing the
-certificate. """.format(cli_command)
-
-# This section is used for --help and --help all ; it needs information
-# about installed plugins to be fully formatted
-COMMAND_OVERVIEW = """The most common SUBCOMMANDS and flags are:
-
-obtain, install, and renew certificates:
-    (default) run   Obtain & install a certificate in your current webserver
-    certonly        Obtain or renew a certificate, but do not install it
-    renew           Renew all previously obtained certificates that are near expiry
-    enhance         Add security enhancements to your existing configuration
-   -d DOMAINS       Comma-separated list of domains to obtain a certificate for
-
-  %s
-  --standalone      Run a standalone webserver for authentication
-  %s
-  --webroot         Place files in a server's webroot folder for authentication
-  --manual          Obtain certificates interactively, or using shell script hooks
-
-   -n               Run non-interactively
-  --test-cert       Obtain a test certificate from a staging server
-  --dry-run         Test "renew" or "certonly" without saving any certificates to disk
-
-manage certificates:
-    certificates    Display information about certificates you have from Certbot
-    revoke          Revoke a certificate (supply --cert-path or --cert-name)
-    delete          Delete a certificate
-
-manage your account with Let's Encrypt:
-    register        Create a Let's Encrypt ACME account
-    update_account  Update a Let's Encrypt ACME account
-  --agree-tos       Agree to the ACME server's Subscriber Agreement
-   -m EMAIL         Email address for important account notifications
-"""
-
-# This is the short help for certbot --help, where we disable argparse
-# altogether
-HELP_AND_VERSION_USAGE = """
-More detailed help:
-
-  -h, --help [TOPIC]    print this message, or detailed help on a topic;
-                        the available TOPICS are:
-
-   all, automation, commands, paths, security, testing, or any of the
-   subcommands or plugins (certonly, renew, install, register, nginx,
-   apache, standalone, webroot, etc.)
-
-  --version             print the version number
-"""
-
-
-# These argparse parameters should be removed when detecting defaults.
-ARGPARSE_PARAMS_TO_REMOVE = ("const", "nargs", "type",)
-
-
-# These sets are used when to help detect options set by the user.
-EXIT_ACTIONS = set(("help", "version",))
-
-
-ZERO_ARG_ACTIONS = set(("store_const", "store_true",
-                        "store_false", "append_const", "count",))
-
-
-# Maps a config option to a set of config options that may have modified it.
-# This dictionary is used recursively, so if A modifies B and B modifies C,
-# it is determined that C was modified by the user if A was modified.
-VAR_MODIFIERS = {"account": set(("server",)),
-                 "renew_hook": set(("deploy_hook",)),
-                 "server": set(("dry_run", "staging",)),
-                 "webroot_map": set(("webroot_path",))}
-
-
-def report_config_interaction(modified, modifiers):
-    """Registers config option interaction to be checked by set_by_cli.
-
-    This function can be called by during the __init__ or
-    add_parser_arguments methods of plugins to register interactions
-    between config options.
-
-    :param modified: config options that can be modified by modifiers
-    :type modified: iterable or str (string_types)
-    :param modifiers: config options that modify modified
-    :type modifiers: iterable or str (string_types)
-
-    """
-    if isinstance(modified, six.string_types):
-        modified = (modified,)
-    if isinstance(modifiers, six.string_types):
-        modifiers = (modifiers,)
-
-    for var in modified:
-        VAR_MODIFIERS.setdefault(var, set()).update(modifiers)
-
-
-def possible_deprecation_warning(config):
-    "A deprecation warning for users with the old, not-self-upgrading letsencrypt-auto."
-    if cli_command != LEAUTO:
-        return
-    if config.no_self_upgrade:
-        # users setting --no-self-upgrade might be hanging on a client version like 0.3.0
-        # or 0.5.0 which is the new script, but doesn't set CERTBOT_AUTO; they don't
-        # need warnings
-        return
-    if "CERTBOT_AUTO" not in os.environ:
-        logger.warning("You are running with an old copy of letsencrypt-auto"
-            " that does not receive updates, and is less reliable than more"
-            " recent versions. The letsencrypt client has also been renamed"
-            " to Certbot. We recommend upgrading to the latest certbot-auto"
-            " script, or using native OS packages.")
-        logger.debug("Deprecation warning circumstances: %s / %s", sys.argv[0], os.environ)
-
-
-class _Default(object):
-    """A class to use as a default to detect if a value is set by a user"""
-
-    def __bool__(self):
-        return False
-
-    def __eq__(self, other):
-        return isinstance(other, _Default)
-
-    def __hash__(self):
-        return id(_Default)
-
-    def __nonzero__(self):
-        return self.__bool__()
-
-
-def set_by_cli(var):
-    """
-    Return True if a particular config variable has been set by the user
-    (CLI or config file) including if the user explicitly set it to the
-    default.  Returns False if the variable was assigned a default value.
-    """
-    detector = set_by_cli.detector  # type: ignore
-    if detector is None and helpful_parser is not None:
-        # Setup on first run: `detector` is a weird version of config in which
-        # the default value of every attribute is wrangled to be boolean-false
-        plugins = plugins_disco.PluginsRegistry.find_all()
-        # reconstructed_args == sys.argv[1:], or whatever was passed to main()
-        reconstructed_args = helpful_parser.args + [helpful_parser.verb]
-        detector = set_by_cli.detector = prepare_and_parse_args(  # type: ignore
-            plugins, reconstructed_args, detect_defaults=True)
-        # propagate plugin requests: eg --standalone modifies config.authenticator
-        detector.authenticator, detector.installer = (  # type: ignore
-            plugin_selection.cli_plugin_requests(detector))
-
-    if not isinstance(getattr(detector, var), _Default):
-        logger.debug("Var %s=%s (set by user).", var, getattr(detector, var))
-        return True
-
-    for modifier in VAR_MODIFIERS.get(var, []):
-        if set_by_cli(modifier):
-            logger.debug("Var %s=%s (set by user).",
-                var, VAR_MODIFIERS.get(var, []))
-            return True
-
-    return False
-
-# static housekeeping var
-# functions attributed are not supported by mypy
-# https://github.com/python/mypy/issues/2087
-set_by_cli.detector = None  # type: ignore
-
-
-def has_default_value(option, value):
-    """Does option have the default value?
-
-    If the default value of option is not known, False is returned.
-
-    :param str option: configuration variable being considered
-    :param value: value of the configuration variable named option
-
-    :returns: True if option has the default value, otherwise, False
-    :rtype: bool
-
-    """
-    if helpful_parser is not None:
-        return (option in helpful_parser.defaults and
-                helpful_parser.defaults[option] == value)
-    return False
-
-
-def option_was_set(option, value):
-    """Was option set by the user or does it differ from the default?
-
-    :param str option: configuration variable being considered
-    :param value: value of the configuration variable named option
-
-    :returns: True if the option was set, otherwise, False
-    :rtype: bool
-
-    """
-    return set_by_cli(option) or not has_default_value(option, value)
-
-
-def argparse_type(variable):
-    """Return our argparse type function for a config variable (default: str)"""
-    # pylint: disable=protected-access
-    if helpful_parser is not None:
-        for action in helpful_parser.parser._actions:
-            if action.type is not None and action.dest == variable:
-                return action.type
-    return str
-
-def read_file(filename, mode="rb"):
-    """Returns the given file's contents.
-
-    :param str filename: path to file
-    :param str mode: open mode (see `open`)
-
-    :returns: absolute path of filename and its contents
-    :rtype: tuple
-
-    :raises argparse.ArgumentTypeError: File does not exist or is not readable.
-
-    """
-    try:
-        filename = os.path.abspath(filename)
-        with open(filename, mode) as the_file:
-            contents = the_file.read()
-        return filename, contents
-    except IOError as exc:
-        raise argparse.ArgumentTypeError(exc.strerror)
-
-
-def flag_default(name):
-    """Default value for CLI flag."""
-    # XXX: this is an internal housekeeping notion of defaults before
-    # argparse has been set up; it is not accurate for all flags.  Call it
-    # with caution.  Plugin defaults are missing, and some things are using
-    # defaults defined in this file, not in constants.py :(
-    return copy.deepcopy(constants.CLI_DEFAULTS[name])
-
-
-def config_help(name, hidden=False):
-    """Extract the help message for an `.IConfig` attribute."""
-    # pylint: disable=no-member
-    if hidden:
-        return argparse.SUPPRESS
-    else:
-        field = interfaces.IConfig.__getitem__(name) # type: zope.interface.interface.Attribute
-        return field.__doc__
-
-
-class HelpfulArgumentGroup(object):
-    """Emulates an argparse group for use with HelpfulArgumentParser.
-
-    This class is used in the add_group method of HelpfulArgumentParser.
-    Command line arguments can be added to the group, but help
-    suppression and default detection is applied by
-    HelpfulArgumentParser when necessary.
-
-    """
-    def __init__(self, helpful_arg_parser, topic):
-        self._parser = helpful_arg_parser
-        self._topic = topic
-
-    def add_argument(self, *args, **kwargs):
-        """Add a new command line argument to the argument group."""
-        self._parser.add(self._topic, *args, **kwargs)
-
-class CustomHelpFormatter(argparse.HelpFormatter):
-    """This is a clone of ArgumentDefaultsHelpFormatter, with bugfixes.
-
-    In particular we fix https://bugs.python.org/issue28742
-    """
-
-    def _get_help_string(self, action):
-        helpstr = action.help
-        if '%(default)' not in action.help and '(default:' not in action.help:
-            if action.default != argparse.SUPPRESS:
-                defaulting_nargs = [argparse.OPTIONAL, argparse.ZERO_OR_MORE]
-                if action.option_strings or action.nargs in defaulting_nargs:
-                    helpstr += ' (default: %(default)s)'
-        return helpstr
-
-# The attributes here are:
-# short: a string that will be displayed by "certbot -h commands"
-# opts:  a string that heads the section of flags with which this command is documented,
-#        both for "certbot -h SUBCOMMAND" and "certbot -h all"
-# usage: an optional string that overrides the header of "certbot -h SUBCOMMAND"
-VERB_HELP = [
-    ("run (default)", {
-        "short": "Obtain/renew a certificate, and install it",
-        "opts": "Options for obtaining & installing certificates",
-        "usage": SHORT_USAGE.replace("[SUBCOMMAND]", ""),
-        "realname": "run"
-    }),
-    ("certonly", {
-        "short": "Obtain or renew a certificate, but do not install it",
-        "opts": "Options for modifying how a certificate is obtained",
-        "usage": ("\n\n  certbot certonly [options] [-d DOMAIN] [-d DOMAIN] ...\n\n"
-                  "This command obtains a TLS/SSL certificate without installing it anywhere.")
-    }),
-    ("renew", {
-        "short": "Renew all certificates (or one specified with --cert-name)",
-        "opts": ("The 'renew' subcommand will attempt to renew all"
-                 " certificates (or more precisely, certificate lineages) you have"
-                 " previously obtained if they are close to expiry, and print a"
-                 " summary of the results. By default, 'renew' will reuse the options"
-                 " used to create obtain or most recently successfully renew each"
-                 " certificate lineage. You can try it with `--dry-run` first. For"
-                 " more fine-grained control, you can renew individual lineages with"
-                 " the `certonly` subcommand. Hooks are available to run commands"
-                 " before and after renewal; see"
-                 " https://certbot.eff.org/docs/using.html#renewal for more"
-                 " information on these."),
-        "usage": "\n\n  certbot renew [--cert-name CERTNAME] [options]\n\n"
-    }),
-    ("certificates", {
-        "short": "List certificates managed by Certbot",
-        "opts": "List certificates managed by Certbot",
-        "usage": ("\n\n  certbot certificates [options] ...\n\n"
-                  "Print information about the status of certificates managed by Certbot.")
-    }),
-    ("delete", {
-        "short": "Clean up all files related to a certificate",
-        "opts": "Options for deleting a certificate",
-        "usage": "\n\n  certbot delete --cert-name CERTNAME\n\n"
-    }),
-    ("revoke", {
-        "short": "Revoke a certificate specified with --cert-path or --cert-name",
-        "opts": "Options for revocation of certificates",
-        "usage": "\n\n  certbot revoke [--cert-path /path/to/fullchain.pem | "
-        "--cert-name example.com] [options]\n\n"
-    }),
-    ("register", {
-        "short": "Register for account with Let's Encrypt / other ACME server",
-        "opts": "Options for account registration",
-        "usage": "\n\n  certbot register --email user@example.com [options]\n\n"
-    }),
-    ("update_account", {
-        "short": "Update existing account with Let's Encrypt / other ACME server",
-        "opts": "Options for account modification",
-        "usage": "\n\n  certbot update_account --email updated_email@example.com [options]\n\n"
-    }),
-    ("unregister", {
-        "short": "Irrevocably deactivate your account",
-        "opts": "Options for account deactivation.",
-        "usage": "\n\n  certbot unregister [options]\n\n"
-    }),
-    ("install", {
-        "short": "Install an arbitrary certificate in a server",
-        "opts": "Options for modifying how a certificate is deployed",
-        "usage": "\n\n  certbot install --cert-path /path/to/fullchain.pem "
-        " --key-path /path/to/private-key [options]\n\n"
-    }),
-    ("config_changes", {
-        "short": "Show changes that Certbot has made to server configurations",
-        "opts": "Options for controlling which changes are displayed",
-        "usage": "\n\n  certbot config_changes --num NUM [options]\n\n"
-    }),
-    ("rollback", {
-        "short": "Roll back server conf changes made during certificate installation",
-        "opts": "Options for rolling back server configuration changes",
-        "usage": "\n\n  certbot rollback --checkpoints 3 [options]\n\n"
-    }),
-    ("plugins", {
-        "short": "List plugins that are installed and available on your system",
-        "opts": 'Options for for the "plugins" subcommand',
-        "usage": "\n\n  certbot plugins [options]\n\n"
-    }),
-    ("update_symlinks", {
-        "short": "Recreate symlinks in your /etc/letsencrypt/live/ directory",
-        "opts": ("Recreates certificate and key symlinks in {0}, if you changed them by hand "
-                 "or edited a renewal configuration file".format(
-                  os.path.join(flag_default("config_dir"), "live"))),
-        "usage": "\n\n  certbot update_symlinks [options]\n\n"
-    }),
-    ("enhance", {
-        "short": "Add security enhancements to your existing configuration",
-        "opts": ("Helps to harden the TLS configuration by adding security enhancements "
-                 "to already existing configuration."),
-        "usage": "\n\n  certbot enhance [options]\n\n"
-    }),
-
-]
-# VERB_HELP is a list in order to preserve order, but a dict is sometimes useful
-VERB_HELP_MAP = dict(VERB_HELP)
-
-
-class HelpfulArgumentParser(object):
-    """Argparse Wrapper.
-
-    This class wraps argparse, adding the ability to make --help less
-    verbose, and request help on specific subcategories at a time, eg
-    'certbot --help security' for security options.
-
-    """
-
-
-    def __init__(self, args, plugins, detect_defaults=False):
-        from certbot import main
-        self.VERBS = {
-            "auth": main.certonly,
-            "certonly": main.certonly,
-            "config_changes": main.config_changes,
-            "run": main.run,
-            "install": main.install,
-            "plugins": main.plugins_cmd,
-            "register": main.register,
-            "update_account": main.update_account,
-            "unregister": main.unregister,
-            "renew": main.renew,
-            "revoke": main.revoke,
-            "rollback": main.rollback,
-            "everything": main.run,
-            "update_symlinks": main.update_symlinks,
-            "certificates": main.certificates,
-            "delete": main.delete,
-            "enhance": main.enhance,
-        }
-
-        # Get notification function for printing
-        try:
-            self.notify = zope.component.getUtility(
-                interfaces.IDisplay).notification
-        except zope_interfaces.ComponentLookupError:
-            self.notify = display_util.NoninteractiveDisplay(
-                sys.stdout).notification
-
-
-        # List of topics for which additional help can be provided
-        HELP_TOPICS = ["all", "security", "paths", "automation", "testing"]
-        HELP_TOPICS += list(self.VERBS) + self.COMMANDS_TOPICS + ["manage"]
-
-        plugin_names = list(plugins)
-        self.help_topics = HELP_TOPICS + plugin_names + [None]  # type: ignore
-
-        self.detect_defaults = detect_defaults
-        self.args = args
-
-        if self.args and self.args[0] == 'help':
-            self.args[0] = '--help'
-
-        self.determine_verb()
-        help1 = self.prescan_for_flag("-h", self.help_topics)
-        help2 = self.prescan_for_flag("--help", self.help_topics)
-        if isinstance(help1, bool) and isinstance(help2, bool):
-            self.help_arg = help1 or help2
-        else:
-            self.help_arg = help1 if isinstance(help1, six.string_types) else help2
-
-        short_usage = self._usage_string(plugins, self.help_arg)
-
-        self.visible_topics = self.determine_help_topics(self.help_arg)
-
-        # elements are added by .add_group()
-        self.groups = {}  # type: Dict[str, argparse._ArgumentGroup]
-        # elements are added by .parse_args()
-        self.defaults = {}  # type: Dict[str, Any]
-
-        self.parser = configargparse.ArgParser(
-            prog="certbot",
-            usage=short_usage,
-            formatter_class=CustomHelpFormatter,
-            args_for_setting_config_path=["-c", "--config"],
-            default_config_files=flag_default("config_files"),
-            config_arg_help_message="path to config file (default: {0})".format(
-                " and ".join(flag_default("config_files"))))
-
-        # This is the only way to turn off overly verbose config flag documentation
-        self.parser._add_config_file_help = False  # pylint: disable=protected-access
-
-    # Help that are synonyms for --help subcommands
-    COMMANDS_TOPICS = ["command", "commands", "subcommand", "subcommands", "verbs"]
-    def _list_subcommands(self):
-        longest = max(len(v) for v in VERB_HELP_MAP.keys())
-
-        text = "The full list of available SUBCOMMANDS is:\n\n"
-        for verb, props in sorted(VERB_HELP):
-            doc = props.get("short", "")
-            text += '{0:<{length}}     {1}\n'.format(verb, doc, length=longest)
-
-        text += "\nYou can get more help on a specific subcommand with --help SUBCOMMAND\n"
-        return text
-
-    def _usage_string(self, plugins, help_arg):
-        """Make usage strings late so that plugins can be initialised late
-
-        :param plugins: all discovered plugins
-        :param help_arg: False for none; True for --help; "TOPIC" for --help TOPIC
-        :rtype: str
-        :returns: a short usage string for the top of --help TOPIC)
-        """
-        if "nginx" in plugins:
-            nginx_doc = "--nginx           Use the Nginx plugin for authentication & installation"
-        else:
-            nginx_doc = "(the certbot nginx plugin is not installed)"
-        if "apache" in plugins:
-            apache_doc = "--apache          Use the Apache plugin for authentication & installation"
-        else:
-            apache_doc = "(the certbot apache plugin is not installed)"
-
-        usage = SHORT_USAGE
-        if help_arg == True:
-            self.notify(usage + COMMAND_OVERVIEW % (apache_doc, nginx_doc) + HELP_AND_VERSION_USAGE)
-            sys.exit(0)
-        elif help_arg in self.COMMANDS_TOPICS:
-            self.notify(usage + self._list_subcommands())
-            sys.exit(0)
-        elif help_arg == "all":
-            # if we're doing --help all, the OVERVIEW is part of the SHORT_USAGE at
-            # the top; if we're doing --help someothertopic, it's OT so it's not
-            usage += COMMAND_OVERVIEW % (apache_doc, nginx_doc)
-        else:
-            custom = VERB_HELP_MAP.get(help_arg, {}).get("usage", None)
-            usage = custom if custom else usage
-
-        return usage
-
-    def remove_config_file_domains_for_renewal(self, parsed_args):
-        """Make "certbot renew" safe if domains are set in cli.ini."""
-        # Works around https://github.com/certbot/certbot/issues/4096
-        if self.verb == "renew":
-            for source, flags in self.parser._source_to_settings.items(): # pylint: disable=protected-access
-                if source.startswith("config_file") and "domains" in flags:
-                    parsed_args.domains = _Default() if self.detect_defaults else []
-
-    def parse_args(self):
-        """Parses command line arguments and returns the result.
-
-        :returns: parsed command line arguments
-        :rtype: argparse.Namespace
-
-        """
-        parsed_args = self.parser.parse_args(self.args)
-        parsed_args.func = self.VERBS[self.verb]
-        parsed_args.verb = self.verb
-
-        self.remove_config_file_domains_for_renewal(parsed_args)
-
-        if self.detect_defaults:
-            return parsed_args
-
-        self.defaults = dict((key, copy.deepcopy(self.parser.get_default(key)))
-                             for key in vars(parsed_args))
-
-        # Do any post-parsing homework here
-
-        if self.verb == "renew":
-            if parsed_args.force_interactive:
-                raise errors.Error(
-                    "{0} cannot be used with renew".format(
-                        constants.FORCE_INTERACTIVE_FLAG))
-            parsed_args.noninteractive_mode = True
-
-        if parsed_args.force_interactive and parsed_args.noninteractive_mode:
-            raise errors.Error(
-                "Flag for non-interactive mode and {0} conflict".format(
-                    constants.FORCE_INTERACTIVE_FLAG))
-
-        if parsed_args.staging or parsed_args.dry_run:
-            self.set_test_server(parsed_args)
-
-        if parsed_args.csr:
-            self.handle_csr(parsed_args)
-
-        if parsed_args.must_staple:
-            parsed_args.staple = True
-
-        if parsed_args.validate_hooks:
-            hooks.validate_hooks(parsed_args)
-
-        if parsed_args.allow_subset_of_names:
-            if any(util.is_wildcard_domain(d) for d in parsed_args.domains):
-                raise errors.Error("Using --allow-subset-of-names with a"
-                                   " wildcard domain is not supported.")
-
-        if parsed_args.hsts and parsed_args.auto_hsts:
-            raise errors.Error(
-                "Parameters --hsts and --auto-hsts cannot be used simultaneously.")
-
-        possible_deprecation_warning(parsed_args)
-
-        return parsed_args
-
-    def set_test_server(self, parsed_args):
-        """We have --staging/--dry-run; perform sanity check and set config.server"""
-
-        if parsed_args.server not in (flag_default("server"), constants.STAGING_URI):
-            conflicts = ["--staging"] if parsed_args.staging else []
-            conflicts += ["--dry-run"] if parsed_args.dry_run else []
-            raise errors.Error("--server value conflicts with {0}".format(
-                " and ".join(conflicts)))
-
-        parsed_args.server = constants.STAGING_URI
-
-        if parsed_args.dry_run:
-            if self.verb not in ["certonly", "renew"]:
-                raise errors.Error("--dry-run currently only works with the "
-                                   "'certonly' or 'renew' subcommands (%r)" % self.verb)
-            parsed_args.break_my_certs = parsed_args.staging = True
-            if glob.glob(os.path.join(parsed_args.config_dir, constants.ACCOUNTS_DIR, "*")):
-                # The user has a prod account, but might not have a staging
-                # one; we don't want to start trying to perform interactive registration
-                parsed_args.tos = True
-                parsed_args.register_unsafely_without_email = True
-
-    def handle_csr(self, parsed_args):
-        """Process a --csr flag."""
-        if parsed_args.verb != "certonly":
-            raise errors.Error("Currently, a CSR file may only be specified "
-                               "when obtaining a new or replacement "
-                               "via the certonly command. Please try the "
-                               "certonly command instead.")
-        if parsed_args.allow_subset_of_names:
-            raise errors.Error("--allow-subset-of-names cannot be used with --csr")
-
-        csrfile, contents = parsed_args.csr[0:2]
-        typ, csr, domains = crypto_util.import_csr_file(csrfile, contents)
-
-        # This is not necessary for webroot to work, however,
-        # obtain_certificate_from_csr requires parsed_args.domains to be set
-        for domain in domains:
-            add_domains(parsed_args, domain)
-
-        if not domains:
-            # TODO: add CN to domains instead:
-            raise errors.Error(
-                "Unfortunately, your CSR %s needs to have a SubjectAltName for every domain"
-                % parsed_args.csr[0])
-
-        parsed_args.actual_csr = (csr, typ)
-
-        csr_domains = set([d.lower() for d in domains])
-        config_domains = set(parsed_args.domains)
-        if csr_domains != config_domains:
-            raise errors.ConfigurationError(
-                "Inconsistent domain requests:\nFrom the CSR: {0}\nFrom command line/config: {1}"
-                .format(", ".join(csr_domains), ", ".join(config_domains)))
-
-
-    def determine_verb(self):
-        """Determines the verb/subcommand provided by the user.
-
-        This function works around some of the limitations of argparse.
-
-        """
-        if "-h" in self.args or "--help" in self.args:
-            # all verbs double as help arguments; don't get them confused
-            self.verb = "help"
-            return
-
-        for i, token in enumerate(self.args):
-            if token in self.VERBS:
-                verb = token
-                if verb == "auth":
-                    verb = "certonly"
-                if verb == "everything":
-                    verb = "run"
-                self.verb = verb
-                self.args.pop(i)
-                return
-
-        self.verb = "run"
-
-    def prescan_for_flag(self, flag, possible_arguments):
-        """Checks cli input for flags.
-
-        Check for a flag, which accepts a fixed set of possible arguments, in
-        the command line; we will use this information to configure argparse's
-        help correctly.  Return the flag's argument, if it has one that matches
-        the sequence @possible_arguments; otherwise return whether the flag is
-        present.
-
-        """
-        if flag not in self.args:
-            return False
-        pos = self.args.index(flag)
-        try:
-            nxt = self.args[pos + 1]
-            if nxt in possible_arguments:
-                return nxt
-        except IndexError:
-            pass
-        return True
-
-    def add(self, topics, *args, **kwargs):
-        """Add a new command line argument.
-
-        :param topics: str or [str] help topic(s) this should be listed under,
-                       or None for "always documented". The first entry
-                       determines where the flag lives in the "--help all"
-                       output (None -> "optional arguments").
-        :param list *args: the names of this argument flag
-        :param dict **kwargs: various argparse settings for this argument
-
-        """
-
-        if isinstance(topics, list):
-            # if this flag can be listed in multiple sections, try to pick the one
-            # that the user has asked for help about
-            topic = self.help_arg if self.help_arg in topics else topics[0]
-        else:
-            topic = topics  # there's only one
-
-        if self.detect_defaults:
-            kwargs = self.modify_kwargs_for_default_detection(**kwargs)
-
-        if self.visible_topics[topic]:
-            if topic in self.groups:
-                group = self.groups[topic]
-                group.add_argument(*args, **kwargs)
-            else:
-                self.parser.add_argument(*args, **kwargs)
-        else:
-            kwargs["help"] = argparse.SUPPRESS
-            self.parser.add_argument(*args, **kwargs)
-
-    def modify_kwargs_for_default_detection(self, **kwargs):
-        """Modify an arg so we can check if it was set by the user.
-
-        Changes the parameters given to argparse when adding an argument
-        so we can properly detect if the value was set by the user.
-
-        :param dict kwargs: various argparse settings for this argument
-
-        :returns: a modified versions of kwargs
-        :rtype: dict
-
-        """
-        action = kwargs.get("action", None)
-        if action not in EXIT_ACTIONS:
-            kwargs["action"] = ("store_true" if action in ZERO_ARG_ACTIONS else
-                                "store")
-            kwargs["default"] = _Default()
-            for param in ARGPARSE_PARAMS_TO_REMOVE:
-                kwargs.pop(param, None)
-
-        return kwargs
-
-    def add_deprecated_argument(self, argument_name, num_args):
-        """Adds a deprecated argument with the name argument_name.
-
-        Deprecated arguments are not shown in the help. If they are used
-        on the command line, a warning is shown stating that the
-        argument is deprecated and no other action is taken.
-
-        :param str argument_name: Name of deprecated argument.
-        :param int nargs: Number of arguments the option takes.
-
-        """
-        util.add_deprecated_argument(
-            self.parser.add_argument, argument_name, num_args)
-
-    def add_group(self, topic, verbs=(), **kwargs):
-        """Create a new argument group.
-
-        This method must be called once for every topic, however, calls
-        to this function are left next to the argument definitions for
-        clarity.
-
-        :param str topic: Name of the new argument group.
-        :param str verbs: List of subcommands that should be documented as part of
-                          this help group / topic
-
-        :returns: The new argument group.
-        :rtype: `HelpfulArgumentGroup`
-
-        """
-        if self.visible_topics[topic]:
-            self.groups[topic] = self.parser.add_argument_group(topic, **kwargs)
-            if self.help_arg:
-                for v in verbs:
-                    self.groups[topic].add_argument(v, help=VERB_HELP_MAP[v]["short"])
-        return HelpfulArgumentGroup(self, topic)
-
-    def add_plugin_args(self, plugins):
-        """
-
-        Let each of the plugins add its own command line arguments, which
-        may or may not be displayed as help topics.
-
-        """
-        for name, plugin_ep in six.iteritems(plugins):
-            parser_or_group = self.add_group(name,
-                                             description=plugin_ep.long_description)
-            plugin_ep.plugin_cls.inject_parser_options(parser_or_group, name)
-
-    def determine_help_topics(self, chosen_topic):
-        """
-
-        The user may have requested help on a topic, return a dict of which
-        topics to display. @chosen_topic has prescan_for_flag's return type
-
-        :returns: dict
-
-        """
-        # topics maps each topic to whether it should be documented by
-        # argparse on the command line
-        if chosen_topic == "auth":
-            chosen_topic = "certonly"
-        if chosen_topic == "everything":
-            chosen_topic = "run"
-        if chosen_topic == "all":
-            # Addition of condition closes #6209 (removal of duplicate route53 option).
-            return dict([(t, True) if t != 'certbot-route53:auth' else (t, False)
-                         for t in self.help_topics])
-        elif not chosen_topic:
-            return dict([(t, False) for t in self.help_topics])
-        else:
-            return dict([(t, t == chosen_topic) for t in self.help_topics])
-
-def _add_all_groups(helpful):
-    helpful.add_group("automation", description="Flags for automating execution & other tweaks")
-    helpful.add_group("security", description="Security parameters & server settings")
-    helpful.add_group("testing",
-        description="The following flags are meant for testing and integration purposes only.")
-    helpful.add_group("paths", description="Flags for changing execution paths & servers")
-    helpful.add_group("manage",
-        description="Various subcommands and flags are available for managing your certificates:",
-        verbs=["certificates", "delete", "renew", "revoke", "update_symlinks"])
-
-    # VERBS
-    for verb, docs in VERB_HELP:
-        name = docs.get("realname", verb)
-        helpful.add_group(name, description=docs["opts"])
-
-
-def prepare_and_parse_args(plugins, args, detect_defaults=False):  # pylint: disable=too-many-statements
-    """Returns parsed command line arguments.
-
-    :param .PluginsRegistry plugins: available plugins
-    :param list args: command line arguments with the program name removed
-
-    :returns: parsed command line arguments
-    :rtype: argparse.Namespace
-
-    """
-
-    # pylint: disable=too-many-statements
-
-    helpful = HelpfulArgumentParser(args, plugins, detect_defaults)
-    _add_all_groups(helpful)
-
-    # --help is automatically provided by argparse
-    helpful.add(
-        None, "-v", "--verbose", dest="verbose_count", action="count",
-        default=flag_default("verbose_count"), help="This flag can be used "
-        "multiple times to incrementally increase the verbosity of output, "
-        "e.g. -vvv.")
-    helpful.add(
-        None, "-t", "--text", dest="text_mode", action="store_true",
-        default=flag_default("text_mode"), help=argparse.SUPPRESS)
-    helpful.add(
-        None, "--max-log-backups", type=nonnegative_int,
-        default=flag_default("max_log_backups"),
-        help="Specifies the maximum number of backup logs that should "
-             "be kept by Certbot's built in log rotation. Setting this "
-             "flag to 0 disables log rotation entirely, causing "
-             "Certbot to always append to the same log file.")
-    helpful.add(
-        [None, "automation", "run", "certonly", "enhance"],
-        "-n", "--non-interactive", "--noninteractive",
-        dest="noninteractive_mode", action="store_true",
-        default=flag_default("noninteractive_mode"),
-        help="Run without ever asking for user input. This may require "
-              "additional command line flags; the client will try to explain "
-              "which ones are required if it finds one missing")
-    helpful.add(
-        [None, "register", "run", "certonly", "enhance"],
-        constants.FORCE_INTERACTIVE_FLAG, action="store_true",
-        default=flag_default("force_interactive"),
-        help="Force Certbot to be interactive even if it detects it's not "
-             "being run in a terminal. This flag cannot be used with the "
-             "renew subcommand.")
-    helpful.add(
-        [None, "run", "certonly", "certificates", "enhance"],
-        "-d", "--domains", "--domain", dest="domains",
-        metavar="DOMAIN", action=_DomainsAction,
-        default=flag_default("domains"),
-        help="Domain names to apply. For multiple domains you can use "
-             "multiple -d flags or enter a comma separated list of domains "
-             "as a parameter. The first domain provided will be the "
-             "subject CN of the certificate, and all domains will be "
-             "Subject Alternative Names on the certificate. "
-             "The first domain will also be used in "
-             "some software user interfaces and as the file paths for the "
-             "certificate and related material unless otherwise "
-             "specified or you already have a certificate with the same "
-             "name. In the case of a name collision it will append a number "
-             "like 0001 to the file path name. (default: Ask)")
-    helpful.add(
-        [None, "run", "certonly", "register"],
-        "--eab-kid", dest="eab_kid",
-        metavar="EAB_KID",
-        help="Key Identifier for External Account Binding"
-    )
-    helpful.add(
-        [None, "run", "certonly", "register"],
-        "--eab-hmac-key", dest="eab_hmac_key",
-        metavar="EAB_HMAC_KEY",
-        help="HMAC key for External Account Binding"
-    )
-    helpful.add(
-        [None, "run", "certonly", "manage", "delete", "certificates",
-         "renew", "enhance"], "--cert-name", dest="certname",
-        metavar="CERTNAME", default=flag_default("certname"),
-        help="Certificate name to apply. This name is used by Certbot for housekeeping "
-             "and in file paths; it doesn't affect the content of the certificate itself. "
-             "To see certificate names, run 'certbot certificates'. "
-             "When creating a new certificate, specifies the new certificate's name. "
-             "(default: the first provided domain or the name of an existing "
-             "certificate on your system for the same domains)")
-    helpful.add(
-        [None, "testing", "renew", "certonly"],
-        "--dry-run", action="store_true", dest="dry_run",
-        default=flag_default("dry_run"),
-        help="Perform a test run of the client, obtaining test (invalid) certificates"
-             " but not saving them to disk. This can currently only be used"
-             " with the 'certonly' and 'renew' subcommands. \nNote: Although --dry-run"
-             " tries to avoid making any persistent changes on a system, it "
-             " is not completely side-effect free: if used with webserver authenticator plugins"
-             " like apache and nginx, it makes and then reverts temporary config changes"
-             " in order to obtain test certificates, and reloads webservers to deploy and then"
-             " roll back those changes.  It also calls --pre-hook and --post-hook commands"
-             " if they are defined because they may be necessary to accurately simulate"
-             " renewal. --deploy-hook commands are not called.")
-    helpful.add(
-        ["register", "automation"], "--register-unsafely-without-email", action="store_true",
-        default=flag_default("register_unsafely_without_email"),
-        help="Specifying this flag enables registering an account with no "
-             "email address. This is strongly discouraged, because in the "
-             "event of key loss or account compromise you will irrevocably "
-             "lose access to your account. You will also be unable to receive "
-             "notice about impending expiration or revocation of your "
-             "certificates. Updates to the Subscriber Agreement will still "
-             "affect you, and will be effective 14 days after posting an "
-             "update to the web site.")
-    # TODO: When `certbot register --update-registration` is fully deprecated,
-    # delete following helpful.add
-    helpful.add(
-        "register", "--update-registration", action="store_true",
-        default=flag_default("update_registration"), dest="update_registration",
-        help=argparse.SUPPRESS)
-    helpful.add(
-        ["register", "update_account", "unregister", "automation"], "-m", "--email",
-        default=flag_default("email"),
-        help=config_help("email"))
-    helpful.add(["register", "update_account", "automation"], "--eff-email", action="store_true",
-                default=flag_default("eff_email"), dest="eff_email",
-                help="Share your e-mail address with EFF")
-    helpful.add(["register", "update_account", "automation"], "--no-eff-email",
-                action="store_false", default=flag_default("eff_email"), dest="eff_email",
-                help="Don't share your e-mail address with EFF")
-    helpful.add(
-        ["automation", "certonly", "run"],
-        "--keep-until-expiring", "--keep", "--reinstall",
-        dest="reinstall", action="store_true", default=flag_default("reinstall"),
-        help="If the requested certificate matches an existing certificate, always keep the "
-             "existing one until it is due for renewal (for the "
-             "'run' subcommand this means reinstall the existing certificate). (default: Ask)")
-    helpful.add(
-        "automation", "--expand", action="store_true", default=flag_default("expand"),
-        help="If an existing certificate is a strict subset of the requested names, "
-             "always expand and replace it with the additional names. (default: Ask)")
-    helpful.add(
-        "automation", "--version", action="version",
-        version="%(prog)s {0}".format(certbot.__version__),
-        help="show program's version number and exit")
-    helpful.add(
-        ["automation", "renew"],
-        "--force-renewal", "--renew-by-default", dest="renew_by_default",
-        action="store_true", default=flag_default("renew_by_default"),
-        help="If a certificate "
-             "already exists for the requested domains, renew it now, "
-             "regardless of whether it is near expiry. (Often "
-             "--keep-until-expiring is more appropriate). Also implies "
-             "--expand.")
-    helpful.add(
-        "automation", "--renew-with-new-domains", dest="renew_with_new_domains",
-        action="store_true", default=flag_default("renew_with_new_domains"),
-        help="If a "
-             "certificate already exists for the requested certificate name "
-             "but does not match the requested domains, renew it now, "
-             "regardless of whether it is near expiry.")
-    helpful.add(
-        "automation", "--reuse-key", dest="reuse_key",
-        action="store_true", default=flag_default("reuse_key"),
-        help="When renewing, use the same private key as the existing "
-             "certificate.")
-
-    helpful.add(
-        ["automation", "renew", "certonly"],
-        "--allow-subset-of-names", action="store_true",
-        default=flag_default("allow_subset_of_names"),
-        help="When performing domain validation, do not consider it a failure "
-             "if authorizations can not be obtained for a strict subset of "
-             "the requested domains. This may be useful for allowing renewals for "
-             "multiple domains to succeed even if some domains no longer point "
-             "at this system. This option cannot be used with --csr.")
-    helpful.add(
-        "automation", "--agree-tos", dest="tos", action="store_true",
-        default=flag_default("tos"),
-        help="Agree to the ACME Subscriber Agreement (default: Ask)")
-    helpful.add(
-        ["unregister", "automation"], "--account", metavar="ACCOUNT_ID",
-        default=flag_default("account"),
-        help="Account ID to use")
-    helpful.add(
-        "automation", "--duplicate", dest="duplicate", action="store_true",
-        default=flag_default("duplicate"),
-        help="Allow making a certificate lineage that duplicates an existing one "
-             "(both can be renewed in parallel)")
-    helpful.add(
-        "automation", "--os-packages-only", action="store_true",
-        default=flag_default("os_packages_only"),
-        help="(certbot-auto only) install OS package dependencies and then stop")
-    helpful.add(
-        "automation", "--no-self-upgrade", action="store_true",
-        default=flag_default("no_self_upgrade"),
-        help="(certbot-auto only) prevent the certbot-auto script from"
-             " upgrading itself to newer released versions (default: Upgrade"
-             " automatically)")
-    helpful.add(
-        "automation", "--no-bootstrap", action="store_true",
-        default=flag_default("no_bootstrap"),
-        help="(certbot-auto only) prevent the certbot-auto script from"
-             " installing OS-level dependencies (default: Prompt to install "
-             " OS-wide dependencies, but exit if the user says 'No')")
-    helpful.add(
-        ["automation", "renew", "certonly", "run"],
-        "-q", "--quiet", dest="quiet", action="store_true",
-        default=flag_default("quiet"),
-        help="Silence all output except errors. Useful for automation via cron."
-             " Implies --non-interactive.")
-    # overwrites server, handled in HelpfulArgumentParser.parse_args()
-    helpful.add(["testing", "revoke", "run"], "--test-cert", "--staging",
-        dest="staging", action="store_true", default=flag_default("staging"),
-        help="Use the staging server to obtain or revoke test (invalid) certificates; equivalent"
-             " to --server " + constants.STAGING_URI)
-    helpful.add(
-        "testing", "--debug", action="store_true", default=flag_default("debug"),
-        help="Show tracebacks in case of errors, and allow certbot-auto "
-             "execution on experimental platforms")
-    helpful.add(
-        [None, "certonly", "run"], "--debug-challenges", action="store_true",
-        default=flag_default("debug_challenges"),
-        help="After setting up challenges, wait for user input before "
-             "submitting to CA")
-    helpful.add(
-        "testing", "--no-verify-ssl", action="store_true",
-        help=config_help("no_verify_ssl"),
-        default=flag_default("no_verify_ssl"))
-    helpful.add(
-        ["testing", "standalone", "apache", "nginx"], "--tls-sni-01-port", type=int,
-        default=flag_default("tls_sni_01_port"),
-        help=config_help("tls_sni_01_port"))
-    helpful.add(
-        ["testing", "standalone"], "--tls-sni-01-address",
-        default=flag_default("tls_sni_01_address"),
-        help=config_help("tls_sni_01_address"))
-    helpful.add(
-        ["testing", "standalone", "manual"], "--http-01-port", type=int,
-        dest="http01_port",
-        default=flag_default("http01_port"), help=config_help("http01_port"))
-    helpful.add(
-        ["testing", "standalone"], "--http-01-address",
-        dest="http01_address",
-        default=flag_default("http01_address"), help=config_help("http01_address"))
-    helpful.add(
-        "testing", "--break-my-certs", action="store_true",
-        default=flag_default("break_my_certs"),
-        help="Be willing to replace or renew valid certificates with invalid "
-             "(testing/staging) certificates")
-    helpful.add(
-        "security", "--rsa-key-size", type=int, metavar="N",
-        default=flag_default("rsa_key_size"), help=config_help("rsa_key_size"))
-    helpful.add(
-        "security", "--must-staple", action="store_true",
-        dest="must_staple", default=flag_default("must_staple"),
-        help=config_help("must_staple"))
-    helpful.add(
-        ["security", "enhance"],
-        "--redirect", action="store_true", dest="redirect",
-        default=flag_default("redirect"),
-        help="Automatically redirect all HTTP traffic to HTTPS for the newly "
-             "authenticated vhost. (default: Ask)")
-    helpful.add(
-        "security", "--no-redirect", action="store_false", dest="redirect",
-        default=flag_default("redirect"),
-        help="Do not automatically redirect all HTTP traffic to HTTPS for the newly "
-             "authenticated vhost. (default: Ask)")
-    helpful.add(
-        ["security", "enhance"],
-        "--hsts", action="store_true", dest="hsts", default=flag_default("hsts"),
-        help="Add the Strict-Transport-Security header to every HTTP response."
-             " Forcing browser to always use SSL for the domain."
-             " Defends against SSL Stripping.")
-    helpful.add(
-        "security", "--no-hsts", action="store_false", dest="hsts",
-        default=flag_default("hsts"), help=argparse.SUPPRESS)
-    helpful.add(
-        ["security", "enhance"],
-        "--uir", action="store_true", dest="uir", default=flag_default("uir"),
-        help='Add the "Content-Security-Policy: upgrade-insecure-requests"'
-             ' header to every HTTP response. Forcing the browser to use'
-             ' https:// for every http:// resource.')
-    helpful.add(
-        "security", "--no-uir", action="store_false", dest="uir", default=flag_default("uir"),
-        help=argparse.SUPPRESS)
-    helpful.add(
-        "security", "--staple-ocsp", action="store_true", dest="staple",
-        default=flag_default("staple"),
-        help="Enables OCSP Stapling. A valid OCSP response is stapled to"
-        " the certificate that the server offers during TLS.")
-    helpful.add(
-        "security", "--no-staple-ocsp", action="store_false", dest="staple",
-        default=flag_default("staple"), help=argparse.SUPPRESS)
-    helpful.add(
-        "security", "--strict-permissions", action="store_true",
-        default=flag_default("strict_permissions"),
-        help="Require that all configuration files are owned by the current "
-             "user; only needed if your config is somewhere unsafe like /tmp/")
-    helpful.add(
-        ["manual", "standalone", "certonly", "renew"],
-        "--preferred-challenges", dest="pref_challs",
-        action=_PrefChallAction, default=flag_default("pref_challs"),
-        help='A sorted, comma delimited list of the preferred challenge to '
-             'use during authorization with the most preferred challenge '
-             'listed first (Eg, "dns" or "tls-sni-01,http,dns"). '
-             'Not all plugins support all challenges. See '
-             'https://certbot.eff.org/docs/using.html#plugins for details. '
-             'ACME Challenges are versioned, but if you pick "http" rather '
-             'than "http-01", Certbot will select the latest version '
-             'automatically.')
-    helpful.add(
-        "renew", "--pre-hook",
-        help="Command to be run in a shell before obtaining any certificates."
-        " Intended primarily for renewal, where it can be used to temporarily"
-        " shut down a webserver that might conflict with the standalone"
-        " plugin. This will only be called if a certificate is actually to be"
-        " obtained/renewed. When renewing several certificates that have"
-        " identical pre-hooks, only the first will be executed.")
-    helpful.add(
-        "renew", "--post-hook",
-        help="Command to be run in a shell after attempting to obtain/renew"
-        " certificates. Can be used to deploy renewed certificates, or to"
-        " restart any servers that were stopped by --pre-hook. This is only"
-        " run if an attempt was made to obtain/renew a certificate. If"
-        " multiple renewed certificates have identical post-hooks, only"
-        " one will be run.")
-    helpful.add("renew", "--renew-hook",
-                action=_RenewHookAction, help=argparse.SUPPRESS)
-    helpful.add(
-        "renew", "--no-random-sleep-on-renew", action="store_false",
-        default=flag_default("random_sleep_on_renew"), dest="random_sleep_on_renew",
-        help=argparse.SUPPRESS)
-    helpful.add(
-        "renew", "--deploy-hook", action=_DeployHookAction,
-        help='Command to be run in a shell once for each successfully'
-        ' issued certificate. For this command, the shell variable'
-        ' $RENEWED_LINEAGE will point to the config live subdirectory'
-        ' (for example, "/etc/letsencrypt/live/example.com") containing'
-        ' the new certificates and keys; the shell variable'
-        ' $RENEWED_DOMAINS will contain a space-delimited list of'
-        ' renewed certificate domains (for example, "example.com'
-        ' www.example.com"')
-    helpful.add(
-        "renew", "--disable-hook-validation",
-        action="store_false", dest="validate_hooks",
-        default=flag_default("validate_hooks"),
-        help="Ordinarily the commands specified for"
-        " --pre-hook/--post-hook/--deploy-hook will be checked for"
-        " validity, to see if the programs being run are in the $PATH,"
-        " so that mistakes can be caught early, even when the hooks"
-        " aren't being run just yet. The validation is rather"
-        " simplistic and fails if you use more advanced shell"
-        " constructs, so you can use this switch to disable it."
-        " (default: False)")
-    helpful.add(
-        "renew", "--no-directory-hooks", action="store_false",
-        default=flag_default("directory_hooks"), dest="directory_hooks",
-        help="Disable running executables found in Certbot's hook directories"
-        " during renewal. (default: False)")
-    helpful.add(
-        "renew", "--disable-renew-updates", action="store_true",
-        default=flag_default("disable_renew_updates"), dest="disable_renew_updates",
-        help="Disable automatic updates to your server configuration that"
-        " would otherwise be done by the selected installer plugin, and triggered"
-        " when the user executes \"certbot renew\", regardless of if the certificate"
-        " is renewed. This setting does not apply to important TLS configuration"
-        " updates.")
-    helpful.add(
-        "renew", "--no-autorenew", action="store_false",
-        default=flag_default("autorenew"), dest="autorenew",
-        help="Disable auto renewal of certificates.")
-
-    helpful.add_deprecated_argument("--agree-dev-preview", 0)
-    helpful.add_deprecated_argument("--dialog", 0)
-
-    # Populate the command line parameters for new style enhancements
-    enhancements.populate_cli(helpful.add)
-
-    _create_subparsers(helpful)
-    _paths_parser(helpful)
-    # _plugins_parsing should be the last thing to act upon the main
-    # parser (--help should display plugin-specific options last)
-    _plugins_parsing(helpful, plugins)
-
-    if not detect_defaults:
-        global helpful_parser # pylint: disable=global-statement
-        helpful_parser = helpful
-    return helpful.parse_args()
-
-
-def _create_subparsers(helpful):
-    helpful.add("config_changes", "--num", type=int, default=flag_default("num"),
-                help="How many past revisions you want to be displayed")
-
-    from certbot.client import sample_user_agent # avoid import loops
-    helpful.add(
-        None, "--user-agent", default=flag_default("user_agent"),
-        help='Set a custom user agent string for the client. User agent strings allow '
-             'the CA to collect high level statistics about success rates by OS, '
-             'plugin and use case, and to know when to deprecate support for past Python '
-             "versions and flags. If you wish to hide this information from the Let's "
-             'Encrypt server, set this to "". '
-             '(default: {0}). The flags encoded in the user agent are: '
-             '--duplicate, --force-renew, --allow-subset-of-names, -n, and '
-             'whether any hooks are set.'.format(sample_user_agent()))
-    helpful.add(
-        None, "--user-agent-comment", default=flag_default("user_agent_comment"),
-        type=_user_agent_comment_type,
-        help="Add a comment to the default user agent string. May be used when repackaging Certbot "
-             "or calling it from another tool to allow additional statistical data to be collected."
-             " Ignored if --user-agent is set. (Example: Foo-Wrapper/1.0)")
-    helpful.add("certonly",
-                "--csr", default=flag_default("csr"), type=read_file,
-                help="Path to a Certificate Signing Request (CSR) in DER or PEM format."
-                " Currently --csr only works with the 'certonly' subcommand.")
-    helpful.add("revoke",
-                "--reason", dest="reason",
-                choices=CaseInsensitiveList(sorted(constants.REVOCATION_REASONS,
-                                                   key=constants.REVOCATION_REASONS.get)),
-                action=_EncodeReasonAction, default=flag_default("reason"),
-                help="Specify reason for revoking certificate. (default: unspecified)")
-    helpful.add("revoke",
-                "--delete-after-revoke", action="store_true",
-                default=flag_default("delete_after_revoke"),
-                help="Delete certificates after revoking them, along with all previous and later "
-                "versions of those certificates.")
-    helpful.add("revoke",
-                "--no-delete-after-revoke", action="store_false",
-                dest="delete_after_revoke",
-                default=flag_default("delete_after_revoke"),
-                help="Do not delete certificates after revoking them. This "
-                     "option should be used with caution because the 'renew' "
-                     "subcommand will attempt to renew undeleted revoked "
-                     "certificates.")
-    helpful.add("rollback",
-                "--checkpoints", type=int, metavar="N",
-                default=flag_default("rollback_checkpoints"),
-                help="Revert configuration N number of checkpoints.")
-    helpful.add("plugins",
-                "--init", action="store_true", default=flag_default("init"),
-                help="Initialize plugins.")
-    helpful.add("plugins",
-                "--prepare", action="store_true", default=flag_default("prepare"),
-                help="Initialize and prepare plugins.")
-    helpful.add("plugins",
-                "--authenticators", action="append_const", dest="ifaces",
-                default=flag_default("ifaces"),
-                const=interfaces.IAuthenticator, help="Limit to authenticator plugins only.")
-    helpful.add("plugins",
-                "--installers", action="append_const", dest="ifaces",
-                default=flag_default("ifaces"),
-                const=interfaces.IInstaller, help="Limit to installer plugins only.")
-
-
-class CaseInsensitiveList(list):
-    """A list that will ignore case when searching.
-
-    This class is passed to the `choices` argument of `argparse.add_arguments`
-    through the `helpful` wrapper. It is necessary due to special handling of
-    command line arguments by `set_by_cli` in which the `type_func` is not applied."""
-    def __contains__(self, element):
-        return super(CaseInsensitiveList, self).__contains__(element.lower())
-
-
-def _paths_parser(helpful):
-    add = helpful.add
-    verb = helpful.verb
-    if verb == "help":
-        verb = helpful.help_arg
-
-    cph = "Path to where certificate is saved (with auth --csr), installed from, or revoked."
-    sections = ["paths", "install", "revoke", "certonly", "manage"]
-    if verb == "certonly":
-        add(sections, "--cert-path", type=os.path.abspath,
-            default=flag_default("auth_cert_path"), help=cph)
-    elif verb == "revoke":
-        add(sections, "--cert-path", type=read_file, required=False, help=cph)
-    else:
-        add(sections, "--cert-path", type=os.path.abspath, help=cph)
-
-    section = "paths"
-    if verb in ("install", "revoke"):
-        section = verb
-    # revoke --key-path reads a file, install --key-path takes a string
-    add(section, "--key-path",
-        type=((verb == "revoke" and read_file) or os.path.abspath),
-        help="Path to private key for certificate installation "
-             "or revocation (if account key is missing)")
-
-    default_cp = None
-    if verb == "certonly":
-        default_cp = flag_default("auth_chain_path")
-    add(["paths", "install"], "--fullchain-path", default=default_cp, type=os.path.abspath,
-        help="Accompanying path to a full certificate chain (certificate plus chain).")
-    add("paths", "--chain-path", default=default_cp, type=os.path.abspath,
-        help="Accompanying path to a certificate chain.")
-    add("paths", "--config-dir", default=flag_default("config_dir"),
-        help=config_help("config_dir"))
-    add("paths", "--work-dir", default=flag_default("work_dir"),
-        help=config_help("work_dir"))
-    add("paths", "--logs-dir", default=flag_default("logs_dir"),
-        help="Logs directory.")
-    add("paths", "--server", default=flag_default("server"),
-        help=config_help("server"))
-
-
-def _plugins_parsing(helpful, plugins):
-    # It's nuts, but there are two "plugins" topics.  Somehow this works
-    helpful.add_group(
-        "plugins", description="Plugin Selection: Certbot client supports an "
-        "extensible plugins architecture. See '%(prog)s plugins' for a "
-        "list of all installed plugins and their names. You can force "
-        "a particular plugin by setting options provided below. Running "
-        "--help <plugin_name> will list flags specific to that plugin.")
-
-    helpful.add("plugins", "--configurator", default=flag_default("configurator"),
-                help="Name of the plugin that is both an authenticator and an installer."
-                " Should not be used together with --authenticator or --installer. "
-                "(default: Ask)")
-    helpful.add("plugins", "-a", "--authenticator", default=flag_default("authenticator"),
-                help="Authenticator plugin name.")
-    helpful.add("plugins", "-i", "--installer", default=flag_default("installer"),
-                help="Installer plugin name (also used to find domains).")
-    helpful.add(["plugins", "certonly", "run", "install", "config_changes"],
-                "--apache", action="store_true", default=flag_default("apache"),
-                help="Obtain and install certificates using Apache")
-    helpful.add(["plugins", "certonly", "run", "install", "config_changes"],
-                "--nginx", action="store_true", default=flag_default("nginx"),
-                help="Obtain and install certificates using Nginx")
-    helpful.add(["plugins", "certonly"], "--standalone", action="store_true",
-                default=flag_default("standalone"),
-                help='Obtain certificates using a "standalone" webserver.')
-    helpful.add(["plugins", "certonly"], "--manual", action="store_true",
-                default=flag_default("manual"),
-                help="Provide laborious manual instructions for obtaining a certificate")
-    helpful.add(["plugins", "certonly"], "--webroot", action="store_true",
-                default=flag_default("webroot"),
-                help="Obtain certificates by placing files in a webroot directory.")
-    helpful.add(["plugins", "certonly"], "--dns-cloudflare", action="store_true",
-                default=flag_default("dns_cloudflare"),
-                help=("Obtain certificates using a DNS TXT record (if you are "
-                      "using Cloudflare for DNS)."))
-    helpful.add(["plugins", "certonly"], "--dns-cloudxns", action="store_true",
-                default=flag_default("dns_cloudxns"),
-                help=("Obtain certificates using a DNS TXT record (if you are "
-                     "using CloudXNS for DNS)."))
-    helpful.add(["plugins", "certonly"], "--dns-digitalocean", action="store_true",
-                default=flag_default("dns_digitalocean"),
-                help=("Obtain certificates using a DNS TXT record (if you are "
-                      "using DigitalOcean for DNS)."))
-    helpful.add(["plugins", "certonly"], "--dns-dnsimple", action="store_true",
-                default=flag_default("dns_dnsimple"),
-                help=("Obtain certificates using a DNS TXT record (if you are "
-                      "using DNSimple for DNS)."))
-    helpful.add(["plugins", "certonly"], "--dns-dnsmadeeasy", action="store_true",
-                default=flag_default("dns_dnsmadeeasy"),
-                help=("Obtain certificates using a DNS TXT record (if you are"
-                      "using DNS Made Easy for DNS)."))
-    helpful.add(["plugins", "certonly"], "--dns-gehirn", action="store_true",
-                default=flag_default("dns_gehirn"),
-                help=("Obtain certificates using a DNS TXT record "
-                     "(if you are using Gehirn Infrastracture Service for DNS)."))
-    helpful.add(["plugins", "certonly"], "--dns-google", action="store_true",
-                default=flag_default("dns_google"),
-                help=("Obtain certificates using a DNS TXT record (if you are "
-                      "using Google Cloud DNS)."))
-    helpful.add(["plugins", "certonly"], "--dns-linode", action="store_true",
-                default=flag_default("dns_linode"),
-                help=("Obtain certificates using a DNS TXT record (if you are "
-                      "using Linode for DNS)."))
-    helpful.add(["plugins", "certonly"], "--dns-luadns", action="store_true",
-                default=flag_default("dns_luadns"),
-                help=("Obtain certificates using a DNS TXT record (if you are "
-                      "using LuaDNS for DNS)."))
-    helpful.add(["plugins", "certonly"], "--dns-nsone", action="store_true",
-                default=flag_default("dns_nsone"),
-                help=("Obtain certificates using a DNS TXT record (if you are "
-                      "using NS1 for DNS)."))
-    helpful.add(["plugins", "certonly"], "--dns-ovh", action="store_true",
-                default=flag_default("dns_ovh"),
-                help=("Obtain certificates using a DNS TXT record (if you are "
-                      "using OVH for DNS)."))
-    helpful.add(["plugins", "certonly"], "--dns-rfc2136", action="store_true",
-                default=flag_default("dns_rfc2136"),
-                help="Obtain certificates using a DNS TXT record (if you are using BIND for DNS).")
-    helpful.add(["plugins", "certonly"], "--dns-route53", action="store_true",
-                default=flag_default("dns_route53"),
-                help=("Obtain certificates using a DNS TXT record (if you are using Route53 for "
-                      "DNS)."))
-    helpful.add(["plugins", "certonly"], "--dns-sakuracloud", action="store_true",
-                default=flag_default("dns_sakuracloud"),
-                help=("Obtain certificates using a DNS TXT record "
-                     "(if you are using Sakura Cloud for DNS)."))
-
-    # things should not be reorder past/pre this comment:
-    # plugins_group should be displayed in --help before plugin
-    # specific groups (so that plugins_group.description makes sense)
-
-    helpful.add_plugin_args(plugins)
-
-
-class _EncodeReasonAction(argparse.Action):
-    """Action class for parsing revocation reason."""
-
-    def __call__(self, parser, namespace, reason, option_string=None):
-        """Encodes the reason for certificate revocation."""
-        code = constants.REVOCATION_REASONS[reason.lower()]
-        setattr(namespace, self.dest, code)
-
-
-class _DomainsAction(argparse.Action):
-    """Action class for parsing domains."""
-
-    def __call__(self, parser, namespace, domain, option_string=None):
-        """Just wrap add_domains in argparseese."""
-        add_domains(namespace, domain)
-
-def add_domains(args_or_config, domains):
-    """Registers new domains to be used during the current client run.
-
-    Domains are not added to the list of requested domains if they have
-    already been registered.
-
-    :param args_or_config: parsed command line arguments
-    :type args_or_config: argparse.Namespace or
-        configuration.NamespaceConfig
-    :param str domain: one or more comma separated domains
-
-    :returns: domains after they have been normalized and validated
-    :rtype: `list` of `str`
-
-    """
-    validated_domains = []
-    for domain in domains.split(","):
-        domain = util.enforce_domain_sanity(domain.strip())
-        validated_domains.append(domain)
-        if domain not in args_or_config.domains:
-            args_or_config.domains.append(domain)
-
-    return validated_domains
-
-class _PrefChallAction(argparse.Action):
-    """Action class for parsing preferred challenges."""
-
-    def __call__(self, parser, namespace, pref_challs, option_string=None):
-        try:
-            challs = parse_preferred_challenges(pref_challs.split(","))
-        except errors.Error as error:
-            raise argparse.ArgumentError(self, str(error))
-        namespace.pref_challs.extend(challs)
-
-
-def parse_preferred_challenges(pref_challs):
-    """Translate and validate preferred challenges.
-
-    :param pref_challs: list of preferred challenge types
-    :type pref_challs: `list` of `str`
-
-    :returns: validated list of preferred challenge types
-    :rtype: `list` of `str`
-
-    :raises errors.Error: if pref_challs is invalid
-
-    """
-    aliases = {"dns": "dns-01", "http": "http-01", "tls-sni": "tls-sni-01"}
-    challs = [c.strip() for c in pref_challs]
-    challs = [aliases.get(c, c) for c in challs]
-    unrecognized = ", ".join(name for name in challs
-                             if name not in challenges.Challenge.TYPES)
-    if unrecognized:
-        raise errors.Error(
-            "Unrecognized challenges: {0}".format(unrecognized))
-    return challs
-
-def _user_agent_comment_type(value):
-    if "(" in value or ")" in value:
-        raise argparse.ArgumentTypeError("may not contain parentheses")
-    return value
-
-class _DeployHookAction(argparse.Action):
-    """Action class for parsing deploy hooks."""
-
-    def __call__(self, parser, namespace, values, option_string=None):
-        renew_hook_set = namespace.deploy_hook != namespace.renew_hook
-        if renew_hook_set and namespace.renew_hook != values:
-            raise argparse.ArgumentError(
-                self, "conflicts with --renew-hook value")
-        namespace.deploy_hook = namespace.renew_hook = values
-
-
-class _RenewHookAction(argparse.Action):
-    """Action class for parsing renew hooks."""
-
-    def __call__(self, parser, namespace, values, option_string=None):
-        deploy_hook_set = namespace.deploy_hook is not None
-        if deploy_hook_set and namespace.deploy_hook != values:
-            raise argparse.ArgumentError(
-                self, "conflicts with --deploy-hook value")
-        namespace.renew_hook = values
-
-
-def nonnegative_int(value):
-    """Converts value to an int and checks that it is not negative.
-
-    This function should used as the type parameter for argparse
-    arguments.
-
-    :param str value: value provided on the command line
-
-    :returns: integer representation of value
-    :rtype: int
-
-    :raises argparse.ArgumentTypeError: if value isn't a non-negative integer
-
-    """
-    try:
-        int_value = int(value)
-    except ValueError:
-        raise argparse.ArgumentTypeError("value must be an integer")
-
-    if int_value < 0:
-        raise argparse.ArgumentTypeError("value must be non-negative")
-    return int_value
diff --git a/certbot/cli/__init__.py b/certbot/cli/__init__.py
new file mode 100644
index 00000000000..520c5f73d77
--- /dev/null
+++ b/certbot/cli/__init__.py
@@ -0,0 +1,537 @@
+"""Certbot command line argument & config processing."""
+# pylint: disable=too-many-lines
+from __future__ import print_function
+import logging
+import logging.handlers
+import argparse
+import sys
+import certbot.plugins.selection as plugin_selection
+from certbot.plugins import disco as plugins_disco
+
+# pylint: disable=unused-import, no-name-in-module
+from acme.magic_typing import Any, Dict, Optional
+# pylint: enable=unused-import, no-name-in-module
+
+import certbot
+from certbot import constants
+
+import certbot.plugins.enhancements as enhancements
+
+
+from certbot.cli.cli_constants import (
+    LEAUTO,
+    old_path_fragment,
+    new_path_prefix,
+    cli_command,
+    SHORT_USAGE,
+    COMMAND_OVERVIEW,
+    HELP_AND_VERSION_USAGE,
+    ARGPARSE_PARAMS_TO_REMOVE,
+    EXIT_ACTIONS,
+    ZERO_ARG_ACTIONS,
+    VAR_MODIFIERS
+)
+
+from certbot.cli.cli_utils import (
+    _Default,
+    read_file,
+    flag_default,
+    config_help,
+    HelpfulArgumentGroup,
+    CustomHelpFormatter,
+    _DomainsAction,
+    add_domains,
+    CaseInsensitiveList,
+    _user_agent_comment_type,
+    _EncodeReasonAction,
+    parse_preferred_challenges,
+    _PrefChallAction,
+    _DeployHookAction,
+    _RenewHookAction,
+    nonnegative_int
+)
+
+# These imports depend on cli_constants and cli_utils.
+from certbot.cli.report_config_interaction import report_config_interaction
+from certbot.cli.warning import possible_deprecation_warning
+from certbot.cli.verb_help import VERB_HELP, VERB_HELP_MAP
+from certbot.cli.group_adder import _add_all_groups
+from certbot.cli.subparsers import _create_subparsers
+from certbot.cli.paths_parser import _paths_parser
+from certbot.cli.plugins_parsing import _plugins_parsing
+
+# These imports depend on some or all of the submodules for cli.
+from certbot.cli.helpful import HelpfulArgumentParser
+
+
+logger = logging.getLogger(__name__)
+
+
+# Global, to save us from a lot of argument passing within the scope of this module
+helpful_parser = None  # type: Optional[HelpfulArgumentParser]
+
+
+def prepare_and_parse_args(plugins, args, detect_defaults=False):  # pylint: disable=too-many-statements
+    """Returns parsed command line arguments.
+
+    :param .PluginsRegistry plugins: available plugins
+    :param list args: command line arguments with the program name removed
+
+    :returns: parsed command line arguments
+    :rtype: argparse.Namespace
+
+    """
+
+    # pylint: disable=too-many-statements
+
+    helpful = HelpfulArgumentParser(args, plugins, detect_defaults)
+    _add_all_groups(helpful)
+
+    # --help is automatically provided by argparse
+    helpful.add(
+        None, "-v", "--verbose", dest="verbose_count", action="count",
+        default=flag_default("verbose_count"), help="This flag can be used "
+        "multiple times to incrementally increase the verbosity of output, "
+        "e.g. -vvv.")
+    helpful.add(
+        None, "-t", "--text", dest="text_mode", action="store_true",
+        default=flag_default("text_mode"), help=argparse.SUPPRESS)
+    helpful.add(
+        None, "--max-log-backups", type=nonnegative_int,
+        default=flag_default("max_log_backups"),
+        help="Specifies the maximum number of backup logs that should "
+             "be kept by Certbot's built in log rotation. Setting this "
+             "flag to 0 disables log rotation entirely, causing "
+             "Certbot to always append to the same log file.")
+    helpful.add(
+        [None, "automation", "run", "certonly", "enhance"],
+        "-n", "--non-interactive", "--noninteractive",
+        dest="noninteractive_mode", action="store_true",
+        default=flag_default("noninteractive_mode"),
+        help="Run without ever asking for user input. This may require "
+              "additional command line flags; the client will try to explain "
+              "which ones are required if it finds one missing")
+    helpful.add(
+        [None, "register", "run", "certonly", "enhance"],
+        constants.FORCE_INTERACTIVE_FLAG, action="store_true",
+        default=flag_default("force_interactive"),
+        help="Force Certbot to be interactive even if it detects it's not "
+             "being run in a terminal. This flag cannot be used with the "
+             "renew subcommand.")
+    helpful.add(
+        [None, "run", "certonly", "certificates", "enhance"],
+        "-d", "--domains", "--domain", dest="domains",
+        metavar="DOMAIN", action=_DomainsAction,
+        default=flag_default("domains"),
+        help="Domain names to apply. For multiple domains you can use "
+             "multiple -d flags or enter a comma separated list of domains "
+             "as a parameter. The first domain provided will be the "
+             "subject CN of the certificate, and all domains will be "
+             "Subject Alternative Names on the certificate. "
+             "The first domain will also be used in "
+             "some software user interfaces and as the file paths for the "
+             "certificate and related material unless otherwise "
+             "specified or you already have a certificate with the same "
+             "name. In the case of a name collision it will append a number "
+             "like 0001 to the file path name. (default: Ask)")
+    helpful.add(
+        [None, "run", "certonly", "register"],
+        "--eab-kid", dest="eab_kid",
+        metavar="EAB_KID",
+        help="Key Identifier for External Account Binding"
+    )
+    helpful.add(
+        [None, "run", "certonly", "register"],
+        "--eab-hmac-key", dest="eab_hmac_key",
+        metavar="EAB_HMAC_KEY",
+        help="HMAC key for External Account Binding"
+    )
+    helpful.add(
+        [None, "run", "certonly", "manage", "delete", "certificates",
+         "renew", "enhance"], "--cert-name", dest="certname",
+        metavar="CERTNAME", default=flag_default("certname"),
+        help="Certificate name to apply. This name is used by Certbot for housekeeping "
+             "and in file paths; it doesn't affect the content of the certificate itself. "
+             "To see certificate names, run 'certbot certificates'. "
+             "When creating a new certificate, specifies the new certificate's name. "
+             "(default: the first provided domain or the name of an existing "
+             "certificate on your system for the same domains)")
+    helpful.add(
+        [None, "testing", "renew", "certonly"],
+        "--dry-run", action="store_true", dest="dry_run",
+        default=flag_default("dry_run"),
+        help="Perform a test run of the client, obtaining test (invalid) certificates"
+             " but not saving them to disk. This can currently only be used"
+             " with the 'certonly' and 'renew' subcommands. \nNote: Although --dry-run"
+             " tries to avoid making any persistent changes on a system, it "
+             " is not completely side-effect free: if used with webserver authenticator plugins"
+             " like apache and nginx, it makes and then reverts temporary config changes"
+             " in order to obtain test certificates, and reloads webservers to deploy and then"
+             " roll back those changes.  It also calls --pre-hook and --post-hook commands"
+             " if they are defined because they may be necessary to accurately simulate"
+             " renewal. --deploy-hook commands are not called.")
+    helpful.add(
+        ["register", "automation"], "--register-unsafely-without-email", action="store_true",
+        default=flag_default("register_unsafely_without_email"),
+        help="Specifying this flag enables registering an account with no "
+             "email address. This is strongly discouraged, because in the "
+             "event of key loss or account compromise you will irrevocably "
+             "lose access to your account. You will also be unable to receive "
+             "notice about impending expiration or revocation of your "
+             "certificates. Updates to the Subscriber Agreement will still "
+             "affect you, and will be effective 14 days after posting an "
+             "update to the web site.")
+    # TODO: When `certbot register --update-registration` is fully deprecated,
+    # delete following helpful.add
+    helpful.add(
+        "register", "--update-registration", action="store_true",
+        default=flag_default("update_registration"), dest="update_registration",
+        help=argparse.SUPPRESS)
+    helpful.add(
+        ["register", "update_account", "unregister", "automation"], "-m", "--email",
+        default=flag_default("email"),
+        help=config_help("email"))
+    helpful.add(["register", "update_account", "automation"], "--eff-email", action="store_true",
+                default=flag_default("eff_email"), dest="eff_email",
+                help="Share your e-mail address with EFF")
+    helpful.add(["register", "update_account", "automation"], "--no-eff-email",
+                action="store_false", default=flag_default("eff_email"), dest="eff_email",
+                help="Don't share your e-mail address with EFF")
+    helpful.add(
+        ["automation", "certonly", "run"],
+        "--keep-until-expiring", "--keep", "--reinstall",
+        dest="reinstall", action="store_true", default=flag_default("reinstall"),
+        help="If the requested certificate matches an existing certificate, always keep the "
+             "existing one until it is due for renewal (for the "
+             "'run' subcommand this means reinstall the existing certificate). (default: Ask)")
+    helpful.add(
+        "automation", "--expand", action="store_true", default=flag_default("expand"),
+        help="If an existing certificate is a strict subset of the requested names, "
+             "always expand and replace it with the additional names. (default: Ask)")
+    helpful.add(
+        "automation", "--version", action="version",
+        version="%(prog)s {0}".format(certbot.__version__),
+        help="show program's version number and exit")
+    helpful.add(
+        ["automation", "renew"],
+        "--force-renewal", "--renew-by-default", dest="renew_by_default",
+        action="store_true", default=flag_default("renew_by_default"),
+        help="If a certificate "
+             "already exists for the requested domains, renew it now, "
+             "regardless of whether it is near expiry. (Often "
+             "--keep-until-expiring is more appropriate). Also implies "
+             "--expand.")
+    helpful.add(
+        "automation", "--renew-with-new-domains", dest="renew_with_new_domains",
+        action="store_true", default=flag_default("renew_with_new_domains"),
+        help="If a "
+             "certificate already exists for the requested certificate name "
+             "but does not match the requested domains, renew it now, "
+             "regardless of whether it is near expiry.")
+    helpful.add(
+        "automation", "--reuse-key", dest="reuse_key",
+        action="store_true", default=flag_default("reuse_key"),
+        help="When renewing, use the same private key as the existing "
+             "certificate.")
+
+    helpful.add(
+        ["automation", "renew", "certonly"],
+        "--allow-subset-of-names", action="store_true",
+        default=flag_default("allow_subset_of_names"),
+        help="When performing domain validation, do not consider it a failure "
+             "if authorizations can not be obtained for a strict subset of "
+             "the requested domains. This may be useful for allowing renewals for "
+             "multiple domains to succeed even if some domains no longer point "
+             "at this system. This option cannot be used with --csr.")
+    helpful.add(
+        "automation", "--agree-tos", dest="tos", action="store_true",
+        default=flag_default("tos"),
+        help="Agree to the ACME Subscriber Agreement (default: Ask)")
+    helpful.add(
+        ["unregister", "automation"], "--account", metavar="ACCOUNT_ID",
+        default=flag_default("account"),
+        help="Account ID to use")
+    helpful.add(
+        "automation", "--duplicate", dest="duplicate", action="store_true",
+        default=flag_default("duplicate"),
+        help="Allow making a certificate lineage that duplicates an existing one "
+             "(both can be renewed in parallel)")
+    helpful.add(
+        "automation", "--os-packages-only", action="store_true",
+        default=flag_default("os_packages_only"),
+        help="(certbot-auto only) install OS package dependencies and then stop")
+    helpful.add(
+        "automation", "--no-self-upgrade", action="store_true",
+        default=flag_default("no_self_upgrade"),
+        help="(certbot-auto only) prevent the certbot-auto script from"
+             " upgrading itself to newer released versions (default: Upgrade"
+             " automatically)")
+    helpful.add(
+        "automation", "--no-bootstrap", action="store_true",
+        default=flag_default("no_bootstrap"),
+        help="(certbot-auto only) prevent the certbot-auto script from"
+             " installing OS-level dependencies (default: Prompt to install "
+             " OS-wide dependencies, but exit if the user says 'No')")
+    helpful.add(
+        ["automation", "renew", "certonly", "run"],
+        "-q", "--quiet", dest="quiet", action="store_true",
+        default=flag_default("quiet"),
+        help="Silence all output except errors. Useful for automation via cron."
+             " Implies --non-interactive.")
+    # overwrites server, handled in HelpfulArgumentParser.parse_args()
+    helpful.add(["testing", "revoke", "run"], "--test-cert", "--staging",
+        dest="staging", action="store_true", default=flag_default("staging"),
+        help="Use the staging server to obtain or revoke test (invalid) certificates; equivalent"
+             " to --server " + constants.STAGING_URI)
+    helpful.add(
+        "testing", "--debug", action="store_true", default=flag_default("debug"),
+        help="Show tracebacks in case of errors, and allow certbot-auto "
+             "execution on experimental platforms")
+    helpful.add(
+        [None, "certonly", "run"], "--debug-challenges", action="store_true",
+        default=flag_default("debug_challenges"),
+        help="After setting up challenges, wait for user input before "
+             "submitting to CA")
+    helpful.add(
+        "testing", "--no-verify-ssl", action="store_true",
+        help=config_help("no_verify_ssl"),
+        default=flag_default("no_verify_ssl"))
+    helpful.add(
+        ["testing", "standalone", "apache", "nginx"], "--tls-sni-01-port", type=int,
+        default=flag_default("tls_sni_01_port"),
+        help=config_help("tls_sni_01_port"))
+    helpful.add(
+        ["testing", "standalone"], "--tls-sni-01-address",
+        default=flag_default("tls_sni_01_address"),
+        help=config_help("tls_sni_01_address"))
+    helpful.add(
+        ["testing", "standalone", "manual"], "--http-01-port", type=int,
+        dest="http01_port",
+        default=flag_default("http01_port"), help=config_help("http01_port"))
+    helpful.add(
+        ["testing", "standalone"], "--http-01-address",
+        dest="http01_address",
+        default=flag_default("http01_address"), help=config_help("http01_address"))
+    helpful.add(
+        "testing", "--break-my-certs", action="store_true",
+        default=flag_default("break_my_certs"),
+        help="Be willing to replace or renew valid certificates with invalid "
+             "(testing/staging) certificates")
+    helpful.add(
+        "security", "--rsa-key-size", type=int, metavar="N",
+        default=flag_default("rsa_key_size"), help=config_help("rsa_key_size"))
+    helpful.add(
+        "security", "--must-staple", action="store_true",
+        dest="must_staple", default=flag_default("must_staple"),
+        help=config_help("must_staple"))
+    helpful.add(
+        ["security", "enhance"],
+        "--redirect", action="store_true", dest="redirect",
+        default=flag_default("redirect"),
+        help="Automatically redirect all HTTP traffic to HTTPS for the newly "
+             "authenticated vhost. (default: Ask)")
+    helpful.add(
+        "security", "--no-redirect", action="store_false", dest="redirect",
+        default=flag_default("redirect"),
+        help="Do not automatically redirect all HTTP traffic to HTTPS for the newly "
+             "authenticated vhost. (default: Ask)")
+    helpful.add(
+        ["security", "enhance"],
+        "--hsts", action="store_true", dest="hsts", default=flag_default("hsts"),
+        help="Add the Strict-Transport-Security header to every HTTP response."
+             " Forcing browser to always use SSL for the domain."
+             " Defends against SSL Stripping.")
+    helpful.add(
+        "security", "--no-hsts", action="store_false", dest="hsts",
+        default=flag_default("hsts"), help=argparse.SUPPRESS)
+    helpful.add(
+        ["security", "enhance"],
+        "--uir", action="store_true", dest="uir", default=flag_default("uir"),
+        help='Add the "Content-Security-Policy: upgrade-insecure-requests"'
+             ' header to every HTTP response. Forcing the browser to use'
+             ' https:// for every http:// resource.')
+    helpful.add(
+        "security", "--no-uir", action="store_false", dest="uir", default=flag_default("uir"),
+        help=argparse.SUPPRESS)
+    helpful.add(
+        "security", "--staple-ocsp", action="store_true", dest="staple",
+        default=flag_default("staple"),
+        help="Enables OCSP Stapling. A valid OCSP response is stapled to"
+        " the certificate that the server offers during TLS.")
+    helpful.add(
+        "security", "--no-staple-ocsp", action="store_false", dest="staple",
+        default=flag_default("staple"), help=argparse.SUPPRESS)
+    helpful.add(
+        "security", "--strict-permissions", action="store_true",
+        default=flag_default("strict_permissions"),
+        help="Require that all configuration files are owned by the current "
+             "user; only needed if your config is somewhere unsafe like /tmp/")
+    helpful.add(
+        ["manual", "standalone", "certonly", "renew"],
+        "--preferred-challenges", dest="pref_challs",
+        action=_PrefChallAction, default=flag_default("pref_challs"),
+        help='A sorted, comma delimited list of the preferred challenge to '
+             'use during authorization with the most preferred challenge '
+             'listed first (Eg, "dns" or "tls-sni-01,http,dns"). '
+             'Not all plugins support all challenges. See '
+             'https://certbot.eff.org/docs/using.html#plugins for details. '
+             'ACME Challenges are versioned, but if you pick "http" rather '
+             'than "http-01", Certbot will select the latest version '
+             'automatically.')
+    helpful.add(
+        "renew", "--pre-hook",
+        help="Command to be run in a shell before obtaining any certificates."
+        " Intended primarily for renewal, where it can be used to temporarily"
+        " shut down a webserver that might conflict with the standalone"
+        " plugin. This will only be called if a certificate is actually to be"
+        " obtained/renewed. When renewing several certificates that have"
+        " identical pre-hooks, only the first will be executed.")
+    helpful.add(
+        "renew", "--post-hook",
+        help="Command to be run in a shell after attempting to obtain/renew"
+        " certificates. Can be used to deploy renewed certificates, or to"
+        " restart any servers that were stopped by --pre-hook. This is only"
+        " run if an attempt was made to obtain/renew a certificate. If"
+        " multiple renewed certificates have identical post-hooks, only"
+        " one will be run.")
+    helpful.add("renew", "--renew-hook",
+                action=_RenewHookAction, help=argparse.SUPPRESS)
+    helpful.add(
+        "renew", "--no-random-sleep-on-renew", action="store_false",
+        default=flag_default("random_sleep_on_renew"), dest="random_sleep_on_renew",
+        help=argparse.SUPPRESS)
+    helpful.add(
+        "renew", "--deploy-hook", action=_DeployHookAction,
+        help='Command to be run in a shell once for each successfully'
+        ' issued certificate. For this command, the shell variable'
+        ' $RENEWED_LINEAGE will point to the config live subdirectory'
+        ' (for example, "/etc/letsencrypt/live/example.com") containing'
+        ' the new certificates and keys; the shell variable'
+        ' $RENEWED_DOMAINS will contain a space-delimited list of'
+        ' renewed certificate domains (for example, "example.com'
+        ' www.example.com"')
+    helpful.add(
+        "renew", "--disable-hook-validation",
+        action="store_false", dest="validate_hooks",
+        default=flag_default("validate_hooks"),
+        help="Ordinarily the commands specified for"
+        " --pre-hook/--post-hook/--deploy-hook will be checked for"
+        " validity, to see if the programs being run are in the $PATH,"
+        " so that mistakes can be caught early, even when the hooks"
+        " aren't being run just yet. The validation is rather"
+        " simplistic and fails if you use more advanced shell"
+        " constructs, so you can use this switch to disable it."
+        " (default: False)")
+    helpful.add(
+        "renew", "--no-directory-hooks", action="store_false",
+        default=flag_default("directory_hooks"), dest="directory_hooks",
+        help="Disable running executables found in Certbot's hook directories"
+        " during renewal. (default: False)")
+    helpful.add(
+        "renew", "--disable-renew-updates", action="store_true",
+        default=flag_default("disable_renew_updates"), dest="disable_renew_updates",
+        help="Disable automatic updates to your server configuration that"
+        " would otherwise be done by the selected installer plugin, and triggered"
+        " when the user executes \"certbot renew\", regardless of if the certificate"
+        " is renewed. This setting does not apply to important TLS configuration"
+        " updates.")
+    helpful.add(
+        "renew", "--no-autorenew", action="store_false",
+        default=flag_default("autorenew"), dest="autorenew",
+        help="Disable auto renewal of certificates.")
+
+    helpful.add_deprecated_argument("--agree-dev-preview", 0)
+    helpful.add_deprecated_argument("--dialog", 0)
+
+    # Populate the command line parameters for new style enhancements
+    enhancements.populate_cli(helpful.add)
+
+    _create_subparsers(helpful)
+    _paths_parser(helpful)
+    # _plugins_parsing should be the last thing to act upon the main
+    # parser (--help should display plugin-specific options last)
+    _plugins_parsing(helpful, plugins)
+
+    if not detect_defaults:
+        global helpful_parser # pylint: disable=global-statement
+        helpful_parser = helpful
+    return helpful.parse_args()
+
+
+def set_by_cli(var):
+    """
+    Return True if a particular config variable has been set by the user
+    (CLI or config file) including if the user explicitly set it to the
+    default.  Returns False if the variable was assigned a default value.
+    """
+    detector = set_by_cli.detector  # type: ignore
+    if detector is None and helpful_parser is not None:
+        # Setup on first run: `detector` is a weird version of config in which
+        # the default value of every attribute is wrangled to be boolean-false
+        plugins = plugins_disco.PluginsRegistry.find_all()
+        # reconstructed_args == sys.argv[1:], or whatever was passed to main()
+        reconstructed_args = helpful_parser.args + [helpful_parser.verb]
+        detector = set_by_cli.detector = prepare_and_parse_args(  # type: ignore
+            plugins, reconstructed_args, detect_defaults=True)
+        # propagate plugin requests: eg --standalone modifies config.authenticator
+        detector.authenticator, detector.installer = (  # type: ignore
+            plugin_selection.cli_plugin_requests(detector))
+
+    if not isinstance(getattr(detector, var), _Default):
+        logger.debug("Var %s=%s (set by user).", var, getattr(detector, var))
+        return True
+
+    for modifier in VAR_MODIFIERS.get(var, []):
+        if set_by_cli(modifier):
+            logger.debug("Var %s=%s (set by user).",
+                var, VAR_MODIFIERS.get(var, []))
+            return True
+
+    return False
+
+
+# static housekeeping var
+# functions attributed are not supported by mypy
+# https://github.com/python/mypy/issues/2087
+set_by_cli.detector = None  # type: ignore
+
+
+def has_default_value(option, value):
+    """Does option have the default value?
+
+    If the default value of option is not known, False is returned.
+
+    :param str option: configuration variable being considered
+    :param value: value of the configuration variable named option
+
+    :returns: True if option has the default value, otherwise, False
+    :rtype: bool
+
+    """
+    if helpful_parser is not None:
+        return (option in helpful_parser.defaults and
+                helpful_parser.defaults[option] == value)
+    return False
+
+
+def option_was_set(option, value):
+    """Was option set by the user or does it differ from the default?
+
+    :param str option: configuration variable being considered
+    :param value: value of the configuration variable named option
+
+    :returns: True if the option was set, otherwise, False
+    :rtype: bool
+
+    """
+    return set_by_cli(option) or not has_default_value(option, value)
+
+
+def argparse_type(variable):
+    """Return our argparse type function for a config variable (default: str)"""
+    # pylint: disable=protected-access
+    if helpful_parser is not None:
+        for action in helpful_parser.parser._actions:
+            if action.type is not None and action.dest == variable:
+                return action.type
+    return str
diff --git a/certbot/cli/cli_constants.py b/certbot/cli/cli_constants.py
new file mode 100644
index 00000000000..0b60dea4a1f
--- /dev/null
+++ b/certbot/cli/cli_constants.py
@@ -0,0 +1,105 @@
+"""Certbot command line constants"""
+import sys
+import os
+
+# For help strings, figure out how the user ran us.
+# When invoked from letsencrypt-auto, sys.argv[0] is something like:
+# "/home/user/.local/share/certbot/bin/certbot"
+# Note that this won't work if the user set VENV_PATH or XDG_DATA_HOME before
+# running letsencrypt-auto (and sudo stops us from seeing if they did), so it
+# should only be used for purposes where inability to detect letsencrypt-auto
+# fails safely
+
+LEAUTO = "letsencrypt-auto"
+if "CERTBOT_AUTO" in os.environ:
+    # if we're here, this is probably going to be certbot-auto, unless the
+    # user saved the script under a different name
+    LEAUTO = os.path.basename(os.environ["CERTBOT_AUTO"])
+
+old_path_fragment = os.path.join(".local", "share", "letsencrypt")
+new_path_prefix = os.path.abspath(os.path.join(os.sep, "opt",
+                                               "eff.org", "certbot", "venv"))
+if old_path_fragment in sys.argv[0] or sys.argv[0].startswith(new_path_prefix):
+    cli_command = LEAUTO
+else:
+    cli_command = "certbot"
+
+
+# Argparse's help formatting has a lot of unhelpful peculiarities, so we want
+# to replace as much of it as we can...
+
+# This is the stub to include in help generated by argparse
+SHORT_USAGE = """
+  {0} [SUBCOMMAND] [options] [-d DOMAIN] [-d DOMAIN] ...
+
+Certbot can obtain and install HTTPS/TLS/SSL certificates.  By default,
+it will attempt to use a webserver both for obtaining and installing the
+certificate. """.format(cli_command)
+
+# This section is used for --help and --help all ; it needs information
+# about installed plugins to be fully formatted
+COMMAND_OVERVIEW = """The most common SUBCOMMANDS and flags are:
+
+obtain, install, and renew certificates:
+    (default) run   Obtain & install a certificate in your current webserver
+    certonly        Obtain or renew a certificate, but do not install it
+    renew           Renew all previously obtained certificates that are near expiry
+    enhance         Add security enhancements to your existing configuration
+   -d DOMAINS       Comma-separated list of domains to obtain a certificate for
+
+  %s
+  --standalone      Run a standalone webserver for authentication
+  %s
+  --webroot         Place files in a server's webroot folder for authentication
+  --manual          Obtain certificates interactively, or using shell script hooks
+
+   -n               Run non-interactively
+  --test-cert       Obtain a test certificate from a staging server
+  --dry-run         Test "renew" or "certonly" without saving any certificates to disk
+
+manage certificates:
+    certificates    Display information about certificates you have from Certbot
+    revoke          Revoke a certificate (supply --cert-path or --cert-name)
+    delete          Delete a certificate
+
+manage your account with Let's Encrypt:
+    register        Create a Let's Encrypt ACME account
+    update_account  Update a Let's Encrypt ACME account
+  --agree-tos       Agree to the ACME server's Subscriber Agreement
+   -m EMAIL         Email address for important account notifications
+"""
+
+# This is the short help for certbot --help, where we disable argparse
+# altogether
+HELP_AND_VERSION_USAGE = """
+More detailed help:
+
+  -h, --help [TOPIC]    print this message, or detailed help on a topic;
+                        the available TOPICS are:
+
+   all, automation, commands, paths, security, testing, or any of the
+   subcommands or plugins (certonly, renew, install, register, nginx,
+   apache, standalone, webroot, etc.)
+
+  --version             print the version number
+"""
+
+# These argparse parameters should be removed when detecting defaults.
+ARGPARSE_PARAMS_TO_REMOVE = ("const", "nargs", "type",)
+
+
+# These sets are used when to help detect options set by the user.
+EXIT_ACTIONS = set(("help", "version",))
+
+
+ZERO_ARG_ACTIONS = set(("store_const", "store_true",
+                        "store_false", "append_const", "count",))
+
+
+# Maps a config option to a set of config options that may have modified it.
+# This dictionary is used recursively, so if A modifies B and B modifies C,
+# it is determined that C was modified by the user if A was modified.
+VAR_MODIFIERS = {"account": set(("server",)),
+                 "renew_hook": set(("deploy_hook",)),
+                 "server": set(("dry_run", "staging",)),
+                 "webroot_map": set(("webroot_path",))}
diff --git a/certbot/cli/cli_utils.py b/certbot/cli/cli_utils.py
new file mode 100644
index 00000000000..eaf55bcbca5
--- /dev/null
+++ b/certbot/cli/cli_utils.py
@@ -0,0 +1,243 @@
+"""Certbot command line util function"""
+import argparse
+import copy
+import os
+
+from acme import challenges
+from certbot import constants
+from certbot import interfaces
+from certbot import util
+from certbot import errors
+
+# pylint: disable=unused-import, no-name-in-module
+import zope.interface.interface
+from acme.magic_typing import Any, Dict, Optional
+# pylint: enable=unused-import, no-name-in-module
+
+
+class _Default(object):
+    """A class to use as a default to detect if a value is set by a user"""
+
+    def __bool__(self):
+        return False
+
+    def __eq__(self, other):
+        return isinstance(other, _Default)
+
+    def __hash__(self):
+        return id(_Default)
+
+    def __nonzero__(self):
+        return self.__bool__()
+
+
+def read_file(filename, mode="rb"):
+    """Returns the given file's contents.
+
+    :param str filename: path to file
+    :param str mode: open mode (see `open`)
+
+    :returns: absolute path of filename and its contents
+    :rtype: tuple
+
+    :raises argparse.ArgumentTypeError: File does not exist or is not readable.
+
+    """
+    try:
+        filename = os.path.abspath(filename)
+        with open(filename, mode) as the_file:
+            contents = the_file.read()
+        return filename, contents
+    except IOError as exc:
+        raise argparse.ArgumentTypeError(exc.strerror)
+
+
+def flag_default(name):
+    """Default value for CLI flag."""
+    # XXX: this is an internal housekeeping notion of defaults before
+    # argparse has been set up; it is not accurate for all flags.  Call it
+    # with caution.  Plugin defaults are missing, and some things are using
+    # defaults defined in this file, not in constants.py :(
+    return copy.deepcopy(constants.CLI_DEFAULTS[name])
+
+
+def config_help(name, hidden=False):
+    """Extract the help message for an `.IConfig` attribute."""
+    # pylint: disable=no-member
+    if hidden:
+        return argparse.SUPPRESS
+    else:
+        field = interfaces.IConfig.__getitem__(name) # type: zope.interface.interface.Attribute
+        return field.__doc__
+
+
+class HelpfulArgumentGroup(object):
+    """Emulates an argparse group for use with HelpfulArgumentParser.
+
+    This class is used in the add_group method of HelpfulArgumentParser.
+    Command line arguments can be added to the group, but help
+    suppression and default detection is applied by
+    HelpfulArgumentParser when necessary.
+
+    """
+    def __init__(self, helpful_arg_parser, topic):
+        self._parser = helpful_arg_parser
+        self._topic = topic
+
+    def add_argument(self, *args, **kwargs):
+        """Add a new command line argument to the argument group."""
+        self._parser.add(self._topic, *args, **kwargs)
+
+
+class CustomHelpFormatter(argparse.HelpFormatter):
+    """This is a clone of ArgumentDefaultsHelpFormatter, with bugfixes.
+
+    In particular we fix https://bugs.python.org/issue28742
+    """
+
+    def _get_help_string(self, action):
+        helpstr = action.help
+        if '%(default)' not in action.help and '(default:' not in action.help:
+            if action.default != argparse.SUPPRESS:
+                defaulting_nargs = [argparse.OPTIONAL, argparse.ZERO_OR_MORE]
+                if action.option_strings or action.nargs in defaulting_nargs:
+                    helpstr += ' (default: %(default)s)'
+        return helpstr
+
+
+class _DomainsAction(argparse.Action):
+    """Action class for parsing domains."""
+
+    def __call__(self, parser, namespace, domain, option_string=None):
+        """Just wrap add_domains in argparseese."""
+        add_domains(namespace, domain)
+
+
+def add_domains(args_or_config, domains):
+    """Registers new domains to be used during the current client run.
+
+    Domains are not added to the list of requested domains if they have
+    already been registered.
+
+    :param args_or_config: parsed command line arguments
+    :type args_or_config: argparse.Namespace or
+        configuration.NamespaceConfig
+    :param str domain: one or more comma separated domains
+
+    :returns: domains after they have been normalized and validated
+    :rtype: `list` of `str`
+
+    """
+    validated_domains = []
+    for domain in domains.split(","):
+        domain = util.enforce_domain_sanity(domain.strip())
+        validated_domains.append(domain)
+        if domain not in args_or_config.domains:
+            args_or_config.domains.append(domain)
+
+    return validated_domains
+
+
+class CaseInsensitiveList(list):
+    """A list that will ignore case when searching.
+
+    This class is passed to the `choices` argument of `argparse.add_arguments`
+    through the `helpful` wrapper. It is necessary due to special handling of
+    command line arguments by `set_by_cli` in which the `type_func` is not applied."""
+    def __contains__(self, element):
+        return super(CaseInsensitiveList, self).__contains__(element.lower())
+
+
+def _user_agent_comment_type(value):
+    if "(" in value or ")" in value:
+        raise argparse.ArgumentTypeError("may not contain parentheses")
+    return value
+
+
+class _EncodeReasonAction(argparse.Action):
+    """Action class for parsing revocation reason."""
+
+    def __call__(self, parser, namespace, reason, option_string=None):
+        """Encodes the reason for certificate revocation."""
+        code = constants.REVOCATION_REASONS[reason.lower()]
+        setattr(namespace, self.dest, code)
+
+
+def parse_preferred_challenges(pref_challs):
+    """Translate and validate preferred challenges.
+
+    :param pref_challs: list of preferred challenge types
+    :type pref_challs: `list` of `str`
+
+    :returns: validated list of preferred challenge types
+    :rtype: `list` of `str`
+
+    :raises errors.Error: if pref_challs is invalid
+
+    """
+    aliases = {"dns": "dns-01", "http": "http-01", "tls-sni": "tls-sni-01"}
+    challs = [c.strip() for c in pref_challs]
+    challs = [aliases.get(c, c) for c in challs]
+    unrecognized = ", ".join(name for name in challs
+                             if name not in challenges.Challenge.TYPES)
+    if unrecognized:
+        raise errors.Error(
+            "Unrecognized challenges: {0}".format(unrecognized))
+    return challs
+
+
+class _PrefChallAction(argparse.Action):
+    """Action class for parsing preferred challenges."""
+
+    def __call__(self, parser, namespace, pref_challs, option_string=None):
+        try:
+            challs = parse_preferred_challenges(pref_challs.split(","))
+        except errors.Error as error:
+            raise argparse.ArgumentError(self, str(error))
+        namespace.pref_challs.extend(challs)
+
+
+class _DeployHookAction(argparse.Action):
+    """Action class for parsing deploy hooks."""
+
+    def __call__(self, parser, namespace, values, option_string=None):
+        renew_hook_set = namespace.deploy_hook != namespace.renew_hook
+        if renew_hook_set and namespace.renew_hook != values:
+            raise argparse.ArgumentError(
+                self, "conflicts with --renew-hook value")
+        namespace.deploy_hook = namespace.renew_hook = values
+
+
+class _RenewHookAction(argparse.Action):
+    """Action class for parsing renew hooks."""
+
+    def __call__(self, parser, namespace, values, option_string=None):
+        deploy_hook_set = namespace.deploy_hook is not None
+        if deploy_hook_set and namespace.deploy_hook != values:
+            raise argparse.ArgumentError(
+                self, "conflicts with --deploy-hook value")
+        namespace.renew_hook = values
+
+
+def nonnegative_int(value):
+    """Converts value to an int and checks that it is not negative.
+
+    This function should used as the type parameter for argparse
+    arguments.
+
+    :param str value: value provided on the command line
+
+    :returns: integer representation of value
+    :rtype: int
+
+    :raises argparse.ArgumentTypeError: if value isn't a non-negative integer
+
+    """
+    try:
+        int_value = int(value)
+    except ValueError:
+        raise argparse.ArgumentTypeError("value must be an integer")
+
+    if int_value < 0:
+        raise argparse.ArgumentTypeError("value must be non-negative")
+    return int_value
diff --git a/certbot/cli/group_adder.py b/certbot/cli/group_adder.py
new file mode 100644
index 00000000000..9a1fc503e30
--- /dev/null
+++ b/certbot/cli/group_adder.py
@@ -0,0 +1,19 @@
+"""This module contains a function to add the groups of arguments for the help
+display"""
+from certbot.cli import VERB_HELP
+
+
+def _add_all_groups(helpful):
+    helpful.add_group("automation", description="Flags for automating execution & other tweaks")
+    helpful.add_group("security", description="Security parameters & server settings")
+    helpful.add_group("testing",
+        description="The following flags are meant for testing and integration purposes only.")
+    helpful.add_group("paths", description="Flags for changing execution paths & servers")
+    helpful.add_group("manage",
+        description="Various subcommands and flags are available for managing your certificates:",
+        verbs=["certificates", "delete", "renew", "revoke", "update_symlinks"])
+
+    # VERBS
+    for verb, docs in VERB_HELP:
+        name = docs.get("realname", verb)
+        helpful.add_group(name, description=docs["opts"])
diff --git a/certbot/cli/helpful.py b/certbot/cli/helpful.py
new file mode 100644
index 00000000000..7249bee5358
--- /dev/null
+++ b/certbot/cli/helpful.py
@@ -0,0 +1,467 @@
+"""Certbot command line argument parser"""
+from __future__ import print_function
+import argparse
+import copy
+import glob
+import os
+import sys
+import configargparse
+import six
+import zope.component
+import zope.interface
+
+from zope.interface import interfaces as zope_interfaces
+
+# pylint: disable=unused-import, no-name-in-module
+from acme.magic_typing import Any, Dict, Optional
+# pylint: enable=unused-import, no-name-in-module
+
+from certbot import constants
+from certbot import crypto_util
+from certbot import errors
+from certbot import hooks
+from certbot import interfaces
+from certbot import util
+
+from certbot.display import util as display_util
+
+from certbot.cli import (
+    SHORT_USAGE,
+    CustomHelpFormatter,
+    flag_default,
+    VERB_HELP,
+    VERB_HELP_MAP,
+    COMMAND_OVERVIEW,
+    HELP_AND_VERSION_USAGE,
+    _Default,
+    possible_deprecation_warning,
+    add_domains,
+    EXIT_ACTIONS,
+    ZERO_ARG_ACTIONS,
+    ARGPARSE_PARAMS_TO_REMOVE,
+    HelpfulArgumentGroup
+)
+
+
+class HelpfulArgumentParser(object):
+    """Argparse Wrapper.
+
+    This class wraps argparse, adding the ability to make --help less
+    verbose, and request help on specific subcategories at a time, eg
+    'certbot --help security' for security options.
+
+    """
+
+
+    def __init__(self, args, plugins, detect_defaults=False):
+        from certbot import main
+        self.VERBS = {
+            "auth": main.certonly,
+            "certonly": main.certonly,
+            "config_changes": main.config_changes,
+            "run": main.run,
+            "install": main.install,
+            "plugins": main.plugins_cmd,
+            "register": main.register,
+            "update_account": main.update_account,
+            "unregister": main.unregister,
+            "renew": main.renew,
+            "revoke": main.revoke,
+            "rollback": main.rollback,
+            "everything": main.run,
+            "update_symlinks": main.update_symlinks,
+            "certificates": main.certificates,
+            "delete": main.delete,
+            "enhance": main.enhance,
+        }
+
+        # Get notification function for printing
+        try:
+            self.notify = zope.component.getUtility(
+                interfaces.IDisplay).notification
+        except zope_interfaces.ComponentLookupError:
+            self.notify = display_util.NoninteractiveDisplay(
+                sys.stdout).notification
+
+
+        # List of topics for which additional help can be provided
+        HELP_TOPICS = ["all", "security", "paths", "automation", "testing"]
+        HELP_TOPICS += list(self.VERBS) + self.COMMANDS_TOPICS + ["manage"]
+
+        plugin_names = list(plugins)
+        self.help_topics = HELP_TOPICS + plugin_names + [None]  # type: ignore
+
+        self.detect_defaults = detect_defaults
+        self.args = args
+
+        if self.args and self.args[0] == 'help':
+            self.args[0] = '--help'
+
+        self.determine_verb()
+        help1 = self.prescan_for_flag("-h", self.help_topics)
+        help2 = self.prescan_for_flag("--help", self.help_topics)
+        if isinstance(help1, bool) and isinstance(help2, bool):
+            self.help_arg = help1 or help2
+        else:
+            self.help_arg = help1 if isinstance(help1, six.string_types) else help2
+
+        short_usage = self._usage_string(plugins, self.help_arg)
+
+        self.visible_topics = self.determine_help_topics(self.help_arg)
+
+        # elements are added by .add_group()
+        self.groups = {}  # type: Dict[str, argparse._ArgumentGroup]
+        # elements are added by .parse_args()
+        self.defaults = {}  # type: Dict[str, Any]
+
+        self.parser = configargparse.ArgParser(
+            prog="certbot",
+            usage=short_usage,
+            formatter_class=CustomHelpFormatter,
+            args_for_setting_config_path=["-c", "--config"],
+            default_config_files=flag_default("config_files"),
+            config_arg_help_message="path to config file (default: {0})".format(
+                " and ".join(flag_default("config_files"))))
+
+        # This is the only way to turn off overly verbose config flag documentation
+        self.parser._add_config_file_help = False  # pylint: disable=protected-access
+
+    # Help that are synonyms for --help subcommands
+    COMMANDS_TOPICS = ["command", "commands", "subcommand", "subcommands", "verbs"]
+    def _list_subcommands(self):
+        longest = max(len(v) for v in VERB_HELP_MAP.keys())
+
+        text = "The full list of available SUBCOMMANDS is:\n\n"
+        for verb, props in sorted(VERB_HELP):
+            doc = props.get("short", "")
+            text += '{0:<{length}}     {1}\n'.format(verb, doc, length=longest)
+
+        text += "\nYou can get more help on a specific subcommand with --help SUBCOMMAND\n"
+        return text
+
+    def _usage_string(self, plugins, help_arg):
+        """Make usage strings late so that plugins can be initialised late
+
+        :param plugins: all discovered plugins
+        :param help_arg: False for none; True for --help; "TOPIC" for --help TOPIC
+        :rtype: str
+        :returns: a short usage string for the top of --help TOPIC)
+        """
+        if "nginx" in plugins:
+            nginx_doc = "--nginx           Use the Nginx plugin for authentication & installation"
+        else:
+            nginx_doc = "(the certbot nginx plugin is not installed)"
+        if "apache" in plugins:
+            apache_doc = "--apache          Use the Apache plugin for authentication & installation"
+        else:
+            apache_doc = "(the certbot apache plugin is not installed)"
+
+        usage = SHORT_USAGE
+        if help_arg == True:
+            self.notify(usage + COMMAND_OVERVIEW % (apache_doc, nginx_doc) + HELP_AND_VERSION_USAGE)
+            sys.exit(0)
+        elif help_arg in self.COMMANDS_TOPICS:
+            self.notify(usage + self._list_subcommands())
+            sys.exit(0)
+        elif help_arg == "all":
+            # if we're doing --help all, the OVERVIEW is part of the SHORT_USAGE at
+            # the top; if we're doing --help someothertopic, it's OT so it's not
+            usage += COMMAND_OVERVIEW % (apache_doc, nginx_doc)
+        else:
+            custom = VERB_HELP_MAP.get(help_arg, {}).get("usage", None)
+            usage = custom if custom else usage
+
+        return usage
+
+    def remove_config_file_domains_for_renewal(self, parsed_args):
+        """Make "certbot renew" safe if domains are set in cli.ini."""
+        # Works around https://github.com/certbot/certbot/issues/4096
+        if self.verb == "renew":
+            for source, flags in self.parser._source_to_settings.items(): # pylint: disable=protected-access
+                if source.startswith("config_file") and "domains" in flags:
+                    parsed_args.domains = _Default() if self.detect_defaults else []
+
+    def parse_args(self):
+        """Parses command line arguments and returns the result.
+
+        :returns: parsed command line arguments
+        :rtype: argparse.Namespace
+
+        """
+        parsed_args = self.parser.parse_args(self.args)
+        parsed_args.func = self.VERBS[self.verb]
+        parsed_args.verb = self.verb
+
+        self.remove_config_file_domains_for_renewal(parsed_args)
+
+        if self.detect_defaults:
+            return parsed_args
+
+        self.defaults = dict((key, copy.deepcopy(self.parser.get_default(key)))
+                             for key in vars(parsed_args))
+
+        # Do any post-parsing homework here
+
+        if self.verb == "renew":
+            if parsed_args.force_interactive:
+                raise errors.Error(
+                    "{0} cannot be used with renew".format(
+                        constants.FORCE_INTERACTIVE_FLAG))
+            parsed_args.noninteractive_mode = True
+
+        if parsed_args.force_interactive and parsed_args.noninteractive_mode:
+            raise errors.Error(
+                "Flag for non-interactive mode and {0} conflict".format(
+                    constants.FORCE_INTERACTIVE_FLAG))
+
+        if parsed_args.staging or parsed_args.dry_run:
+            self.set_test_server(parsed_args)
+
+        if parsed_args.csr:
+            self.handle_csr(parsed_args)
+
+        if parsed_args.must_staple:
+            parsed_args.staple = True
+
+        if parsed_args.validate_hooks:
+            hooks.validate_hooks(parsed_args)
+
+        if parsed_args.allow_subset_of_names:
+            if any(util.is_wildcard_domain(d) for d in parsed_args.domains):
+                raise errors.Error("Using --allow-subset-of-names with a"
+                                   " wildcard domain is not supported.")
+
+        if parsed_args.hsts and parsed_args.auto_hsts:
+            raise errors.Error(
+                "Parameters --hsts and --auto-hsts cannot be used simultaneously.")
+
+        possible_deprecation_warning(parsed_args)
+
+        return parsed_args
+
+    def set_test_server(self, parsed_args):
+        """We have --staging/--dry-run; perform sanity check and set config.server"""
+
+        if parsed_args.server not in (flag_default("server"), constants.STAGING_URI):
+            conflicts = ["--staging"] if parsed_args.staging else []
+            conflicts += ["--dry-run"] if parsed_args.dry_run else []
+            raise errors.Error("--server value conflicts with {0}".format(
+                " and ".join(conflicts)))
+
+        parsed_args.server = constants.STAGING_URI
+
+        if parsed_args.dry_run:
+            if self.verb not in ["certonly", "renew"]:
+                raise errors.Error("--dry-run currently only works with the "
+                                   "'certonly' or 'renew' subcommands (%r)" % self.verb)
+            parsed_args.break_my_certs = parsed_args.staging = True
+            if glob.glob(os.path.join(parsed_args.config_dir, constants.ACCOUNTS_DIR, "*")):
+                # The user has a prod account, but might not have a staging
+                # one; we don't want to start trying to perform interactive registration
+                parsed_args.tos = True
+                parsed_args.register_unsafely_without_email = True
+
+    def handle_csr(self, parsed_args):
+        """Process a --csr flag."""
+        if parsed_args.verb != "certonly":
+            raise errors.Error("Currently, a CSR file may only be specified "
+                               "when obtaining a new or replacement "
+                               "via the certonly command. Please try the "
+                               "certonly command instead.")
+        if parsed_args.allow_subset_of_names:
+            raise errors.Error("--allow-subset-of-names cannot be used with --csr")
+
+        csrfile, contents = parsed_args.csr[0:2]
+        typ, csr, domains = crypto_util.import_csr_file(csrfile, contents)
+
+        # This is not necessary for webroot to work, however,
+        # obtain_certificate_from_csr requires parsed_args.domains to be set
+        for domain in domains:
+            add_domains(parsed_args, domain)
+
+        if not domains:
+            # TODO: add CN to domains instead:
+            raise errors.Error(
+                "Unfortunately, your CSR %s needs to have a SubjectAltName for every domain"
+                % parsed_args.csr[0])
+
+        parsed_args.actual_csr = (csr, typ)
+
+        csr_domains = set([d.lower() for d in domains])
+        config_domains = set(parsed_args.domains)
+        if csr_domains != config_domains:
+            raise errors.ConfigurationError(
+                "Inconsistent domain requests:\nFrom the CSR: {0}\nFrom command line/config: {1}"
+                .format(", ".join(csr_domains), ", ".join(config_domains)))
+
+
+    def determine_verb(self):
+        """Determines the verb/subcommand provided by the user.
+
+        This function works around some of the limitations of argparse.
+
+        """
+        if "-h" in self.args or "--help" in self.args:
+            # all verbs double as help arguments; don't get them confused
+            self.verb = "help"
+            return
+
+        for i, token in enumerate(self.args):
+            if token in self.VERBS:
+                verb = token
+                if verb == "auth":
+                    verb = "certonly"
+                if verb == "everything":
+                    verb = "run"
+                self.verb = verb
+                self.args.pop(i)
+                return
+
+        self.verb = "run"
+
+    def prescan_for_flag(self, flag, possible_arguments):
+        """Checks cli input for flags.
+
+        Check for a flag, which accepts a fixed set of possible arguments, in
+        the command line; we will use this information to configure argparse's
+        help correctly.  Return the flag's argument, if it has one that matches
+        the sequence @possible_arguments; otherwise return whether the flag is
+        present.
+
+        """
+        if flag not in self.args:
+            return False
+        pos = self.args.index(flag)
+        try:
+            nxt = self.args[pos + 1]
+            if nxt in possible_arguments:
+                return nxt
+        except IndexError:
+            pass
+        return True
+
+    def add(self, topics, *args, **kwargs):
+        """Add a new command line argument.
+
+        :param topics: str or [str] help topic(s) this should be listed under,
+                       or None for "always documented". The first entry
+                       determines where the flag lives in the "--help all"
+                       output (None -> "optional arguments").
+        :param list *args: the names of this argument flag
+        :param dict **kwargs: various argparse settings for this argument
+
+        """
+
+        if isinstance(topics, list):
+            # if this flag can be listed in multiple sections, try to pick the one
+            # that the user has asked for help about
+            topic = self.help_arg if self.help_arg in topics else topics[0]
+        else:
+            topic = topics  # there's only one
+
+        if self.detect_defaults:
+            kwargs = self.modify_kwargs_for_default_detection(**kwargs)
+
+        if self.visible_topics[topic]:
+            if topic in self.groups:
+                group = self.groups[topic]
+                group.add_argument(*args, **kwargs)
+            else:
+                self.parser.add_argument(*args, **kwargs)
+        else:
+            kwargs["help"] = argparse.SUPPRESS
+            self.parser.add_argument(*args, **kwargs)
+
+    def modify_kwargs_for_default_detection(self, **kwargs):
+        """Modify an arg so we can check if it was set by the user.
+
+        Changes the parameters given to argparse when adding an argument
+        so we can properly detect if the value was set by the user.
+
+        :param dict kwargs: various argparse settings for this argument
+
+        :returns: a modified versions of kwargs
+        :rtype: dict
+
+        """
+        action = kwargs.get("action", None)
+        if action not in EXIT_ACTIONS:
+            kwargs["action"] = ("store_true" if action in ZERO_ARG_ACTIONS else
+                                "store")
+            kwargs["default"] = _Default()
+            for param in ARGPARSE_PARAMS_TO_REMOVE:
+                kwargs.pop(param, None)
+
+        return kwargs
+
+    def add_deprecated_argument(self, argument_name, num_args):
+        """Adds a deprecated argument with the name argument_name.
+
+        Deprecated arguments are not shown in the help. If they are used
+        on the command line, a warning is shown stating that the
+        argument is deprecated and no other action is taken.
+
+        :param str argument_name: Name of deprecated argument.
+        :param int nargs: Number of arguments the option takes.
+
+        """
+        util.add_deprecated_argument(
+            self.parser.add_argument, argument_name, num_args)
+
+    def add_group(self, topic, verbs=(), **kwargs):
+        """Create a new argument group.
+
+        This method must be called once for every topic, however, calls
+        to this function are left next to the argument definitions for
+        clarity.
+
+        :param str topic: Name of the new argument group.
+        :param str verbs: List of subcommands that should be documented as part of
+                          this help group / topic
+
+        :returns: The new argument group.
+        :rtype: `HelpfulArgumentGroup`
+
+        """
+        if self.visible_topics[topic]:
+            self.groups[topic] = self.parser.add_argument_group(topic, **kwargs)
+            if self.help_arg:
+                for v in verbs:
+                    self.groups[topic].add_argument(v, help=VERB_HELP_MAP[v]["short"])
+        return HelpfulArgumentGroup(self, topic)
+
+    def add_plugin_args(self, plugins):
+        """
+
+        Let each of the plugins add its own command line arguments, which
+        may or may not be displayed as help topics.
+
+        """
+        for name, plugin_ep in six.iteritems(plugins):
+            parser_or_group = self.add_group(name,
+                                             description=plugin_ep.long_description)
+            plugin_ep.plugin_cls.inject_parser_options(parser_or_group, name)
+
+    def determine_help_topics(self, chosen_topic):
+        """
+
+        The user may have requested help on a topic, return a dict of which
+        topics to display. @chosen_topic has prescan_for_flag's return type
+
+        :returns: dict
+
+        """
+        # topics maps each topic to whether it should be documented by
+        # argparse on the command line
+        if chosen_topic == "auth":
+            chosen_topic = "certonly"
+        if chosen_topic == "everything":
+            chosen_topic = "run"
+        if chosen_topic == "all":
+            # Addition of condition closes #6209 (removal of duplicate route53 option).
+            return dict([(t, True) if t != 'certbot-route53:auth' else (t, False)
+                         for t in self.help_topics])
+        elif not chosen_topic:
+            return dict([(t, False) for t in self.help_topics])
+        else:
+            return dict([(t, t == chosen_topic) for t in self.help_topics])
diff --git a/certbot/cli/paths_parser.py b/certbot/cli/paths_parser.py
new file mode 100644
index 00000000000..970411094fc
--- /dev/null
+++ b/certbot/cli/paths_parser.py
@@ -0,0 +1,51 @@
+"""This is a module that adds configuration to the argument parser regarding
+paths for certificates"""
+import os
+
+from certbot.cli import (
+    read_file,
+    flag_default,
+    config_help
+)
+
+
+def _paths_parser(helpful):
+    add = helpful.add
+    verb = helpful.verb
+    if verb == "help":
+        verb = helpful.help_arg
+
+    cph = "Path to where certificate is saved (with auth --csr), installed from, or revoked."
+    sections = ["paths", "install", "revoke", "certonly", "manage"]
+    if verb == "certonly":
+        add(sections, "--cert-path", type=os.path.abspath,
+            default=flag_default("auth_cert_path"), help=cph)
+    elif verb == "revoke":
+        add(sections, "--cert-path", type=read_file, required=False, help=cph)
+    else:
+        add(sections, "--cert-path", type=os.path.abspath, help=cph)
+
+    section = "paths"
+    if verb in ("install", "revoke"):
+        section = verb
+    # revoke --key-path reads a file, install --key-path takes a string
+    add(section, "--key-path",
+        type=((verb == "revoke" and read_file) or os.path.abspath),
+        help="Path to private key for certificate installation "
+             "or revocation (if account key is missing)")
+
+    default_cp = None
+    if verb == "certonly":
+        default_cp = flag_default("auth_chain_path")
+    add(["paths", "install"], "--fullchain-path", default=default_cp, type=os.path.abspath,
+        help="Accompanying path to a full certificate chain (certificate plus chain).")
+    add("paths", "--chain-path", default=default_cp, type=os.path.abspath,
+        help="Accompanying path to a certificate chain.")
+    add("paths", "--config-dir", default=flag_default("config_dir"),
+        help=config_help("config_dir"))
+    add("paths", "--work-dir", default=flag_default("work_dir"),
+        help=config_help("work_dir"))
+    add("paths", "--logs-dir", default=flag_default("logs_dir"),
+        help="Logs directory.")
+    add("paths", "--server", default=flag_default("server"),
+        help=config_help("server"))
diff --git a/certbot/cli/plugins_parsing.py b/certbot/cli/plugins_parsing.py
new file mode 100644
index 00000000000..404428e07e6
--- /dev/null
+++ b/certbot/cli/plugins_parsing.py
@@ -0,0 +1,97 @@
+"""This is a module that handles parsing of plugins for the argument parser"""
+from certbot.cli import flag_default
+
+
+def _plugins_parsing(helpful, plugins):
+    # It's nuts, but there are two "plugins" topics.  Somehow this works
+    helpful.add_group(
+        "plugins", description="Plugin Selection: Certbot client supports an "
+        "extensible plugins architecture. See '%(prog)s plugins' for a "
+        "list of all installed plugins and their names. You can force "
+        "a particular plugin by setting options provided below. Running "
+        "--help <plugin_name> will list flags specific to that plugin.")
+
+    helpful.add("plugins", "--configurator", default=flag_default("configurator"),
+                help="Name of the plugin that is both an authenticator and an installer."
+                " Should not be used together with --authenticator or --installer. "
+                "(default: Ask)")
+    helpful.add("plugins", "-a", "--authenticator", default=flag_default("authenticator"),
+                help="Authenticator plugin name.")
+    helpful.add("plugins", "-i", "--installer", default=flag_default("installer"),
+                help="Installer plugin name (also used to find domains).")
+    helpful.add(["plugins", "certonly", "run", "install", "config_changes"],
+                "--apache", action="store_true", default=flag_default("apache"),
+                help="Obtain and install certificates using Apache")
+    helpful.add(["plugins", "certonly", "run", "install", "config_changes"],
+                "--nginx", action="store_true", default=flag_default("nginx"),
+                help="Obtain and install certificates using Nginx")
+    helpful.add(["plugins", "certonly"], "--standalone", action="store_true",
+                default=flag_default("standalone"),
+                help='Obtain certificates using a "standalone" webserver.')
+    helpful.add(["plugins", "certonly"], "--manual", action="store_true",
+                default=flag_default("manual"),
+                help="Provide laborious manual instructions for obtaining a certificate")
+    helpful.add(["plugins", "certonly"], "--webroot", action="store_true",
+                default=flag_default("webroot"),
+                help="Obtain certificates by placing files in a webroot directory.")
+    helpful.add(["plugins", "certonly"], "--dns-cloudflare", action="store_true",
+                default=flag_default("dns_cloudflare"),
+                help=("Obtain certificates using a DNS TXT record (if you are "
+                      "using Cloudflare for DNS)."))
+    helpful.add(["plugins", "certonly"], "--dns-cloudxns", action="store_true",
+                default=flag_default("dns_cloudxns"),
+                help=("Obtain certificates using a DNS TXT record (if you are "
+                     "using CloudXNS for DNS)."))
+    helpful.add(["plugins", "certonly"], "--dns-digitalocean", action="store_true",
+                default=flag_default("dns_digitalocean"),
+                help=("Obtain certificates using a DNS TXT record (if you are "
+                      "using DigitalOcean for DNS)."))
+    helpful.add(["plugins", "certonly"], "--dns-dnsimple", action="store_true",
+                default=flag_default("dns_dnsimple"),
+                help=("Obtain certificates using a DNS TXT record (if you are "
+                      "using DNSimple for DNS)."))
+    helpful.add(["plugins", "certonly"], "--dns-dnsmadeeasy", action="store_true",
+                default=flag_default("dns_dnsmadeeasy"),
+                help=("Obtain certificates using a DNS TXT record (if you are"
+                      "using DNS Made Easy for DNS)."))
+    helpful.add(["plugins", "certonly"], "--dns-gehirn", action="store_true",
+                default=flag_default("dns_gehirn"),
+                help=("Obtain certificates using a DNS TXT record "
+                     "(if you are using Gehirn Infrastracture Service for DNS)."))
+    helpful.add(["plugins", "certonly"], "--dns-google", action="store_true",
+                default=flag_default("dns_google"),
+                help=("Obtain certificates using a DNS TXT record (if you are "
+                      "using Google Cloud DNS)."))
+    helpful.add(["plugins", "certonly"], "--dns-linode", action="store_true",
+                default=flag_default("dns_linode"),
+                help=("Obtain certificates using a DNS TXT record (if you are "
+                      "using Linode for DNS)."))
+    helpful.add(["plugins", "certonly"], "--dns-luadns", action="store_true",
+                default=flag_default("dns_luadns"),
+                help=("Obtain certificates using a DNS TXT record (if you are "
+                      "using LuaDNS for DNS)."))
+    helpful.add(["plugins", "certonly"], "--dns-nsone", action="store_true",
+                default=flag_default("dns_nsone"),
+                help=("Obtain certificates using a DNS TXT record (if you are "
+                      "using NS1 for DNS)."))
+    helpful.add(["plugins", "certonly"], "--dns-ovh", action="store_true",
+                default=flag_default("dns_ovh"),
+                help=("Obtain certificates using a DNS TXT record (if you are "
+                      "using OVH for DNS)."))
+    helpful.add(["plugins", "certonly"], "--dns-rfc2136", action="store_true",
+                default=flag_default("dns_rfc2136"),
+                help="Obtain certificates using a DNS TXT record (if you are using BIND for DNS).")
+    helpful.add(["plugins", "certonly"], "--dns-route53", action="store_true",
+                default=flag_default("dns_route53"),
+                help=("Obtain certificates using a DNS TXT record (if you are using Route53 for "
+                      "DNS)."))
+    helpful.add(["plugins", "certonly"], "--dns-sakuracloud", action="store_true",
+                default=flag_default("dns_sakuracloud"),
+                help=("Obtain certificates using a DNS TXT record "
+                     "(if you are using Sakura Cloud for DNS)."))
+
+    # things should not be reorder past/pre this comment:
+    # plugins_group should be displayed in --help before plugin
+    # specific groups (so that plugins_group.description makes sense)
+
+    helpful.add_plugin_args(plugins)
diff --git a/certbot/cli/report_config_interaction.py b/certbot/cli/report_config_interaction.py
new file mode 100644
index 00000000000..c664b667bf5
--- /dev/null
+++ b/certbot/cli/report_config_interaction.py
@@ -0,0 +1,26 @@
+"""This is a module that reports config option interaction that should be
+checled by set_by_cli"""
+import six
+from certbot.cli import VAR_MODIFIERS
+
+
+def report_config_interaction(modified, modifiers):
+    """Registers config option interaction to be checked by set_by_cli.
+
+    This function can be called by during the __init__ or
+    add_parser_arguments methods of plugins to register interactions
+    between config options.
+
+    :param modified: config options that can be modified by modifiers
+    :type modified: iterable or str (string_types)
+    :param modifiers: config options that modify modified
+    :type modifiers: iterable or str (string_types)
+
+    """
+    if isinstance(modified, six.string_types):
+        modified = (modified,)
+    if isinstance(modifiers, six.string_types):
+        modifiers = (modifiers,)
+
+    for var in modified:
+        VAR_MODIFIERS.setdefault(var, set()).update(modifiers)
diff --git a/certbot/cli/subparsers.py b/certbot/cli/subparsers.py
new file mode 100644
index 00000000000..da2649ca90b
--- /dev/null
+++ b/certbot/cli/subparsers.py
@@ -0,0 +1,75 @@
+"""This module creates subparsers for the argument parser"""
+from certbot import constants
+from certbot import interfaces
+
+from certbot.cli import (
+    flag_default,
+    read_file,
+    CaseInsensitiveList,
+    _user_agent_comment_type,
+    _EncodeReasonAction
+)
+
+
+def _create_subparsers(helpful):
+    helpful.add("config_changes", "--num", type=int, default=flag_default("num"),
+                help="How many past revisions you want to be displayed")
+
+    from certbot.client import sample_user_agent # avoid import loops
+    helpful.add(
+        None, "--user-agent", default=flag_default("user_agent"),
+        help='Set a custom user agent string for the client. User agent strings allow '
+             'the CA to collect high level statistics about success rates by OS, '
+             'plugin and use case, and to know when to deprecate support for past Python '
+             "versions and flags. If you wish to hide this information from the Let's "
+             'Encrypt server, set this to "". '
+             '(default: {0}). The flags encoded in the user agent are: '
+             '--duplicate, --force-renew, --allow-subset-of-names, -n, and '
+             'whether any hooks are set.'.format(sample_user_agent()))
+    helpful.add(
+        None, "--user-agent-comment", default=flag_default("user_agent_comment"),
+        type=_user_agent_comment_type,
+        help="Add a comment to the default user agent string. May be used when repackaging Certbot "
+             "or calling it from another tool to allow additional statistical data to be collected."
+             " Ignored if --user-agent is set. (Example: Foo-Wrapper/1.0)")
+    helpful.add("certonly",
+                "--csr", default=flag_default("csr"), type=read_file,
+                help="Path to a Certificate Signing Request (CSR) in DER or PEM format."
+                " Currently --csr only works with the 'certonly' subcommand.")
+    helpful.add("revoke",
+                "--reason", dest="reason",
+                choices=CaseInsensitiveList(sorted(constants.REVOCATION_REASONS,
+                                                   key=constants.REVOCATION_REASONS.get)),
+                action=_EncodeReasonAction, default=flag_default("reason"),
+                help="Specify reason for revoking certificate. (default: unspecified)")
+    helpful.add("revoke",
+                "--delete-after-revoke", action="store_true",
+                default=flag_default("delete_after_revoke"),
+                help="Delete certificates after revoking them, along with all previous and later "
+                "versions of those certificates.")
+    helpful.add("revoke",
+                "--no-delete-after-revoke", action="store_false",
+                dest="delete_after_revoke",
+                default=flag_default("delete_after_revoke"),
+                help="Do not delete certificates after revoking them. This "
+                     "option should be used with caution because the 'renew' "
+                     "subcommand will attempt to renew undeleted revoked "
+                     "certificates.")
+    helpful.add("rollback",
+                "--checkpoints", type=int, metavar="N",
+                default=flag_default("rollback_checkpoints"),
+                help="Revert configuration N number of checkpoints.")
+    helpful.add("plugins",
+                "--init", action="store_true", default=flag_default("init"),
+                help="Initialize plugins.")
+    helpful.add("plugins",
+                "--prepare", action="store_true", default=flag_default("prepare"),
+                help="Initialize and prepare plugins.")
+    helpful.add("plugins",
+                "--authenticators", action="append_const", dest="ifaces",
+                default=flag_default("ifaces"),
+                const=interfaces.IAuthenticator, help="Limit to authenticator plugins only.")
+    helpful.add("plugins",
+                "--installers", action="append_const", dest="ifaces",
+                default=flag_default("ifaces"),
+                const=interfaces.IInstaller, help="Limit to installer plugins only.")
diff --git a/certbot/cli/verb_help.py b/certbot/cli/verb_help.py
new file mode 100644
index 00000000000..cc07bb54157
--- /dev/null
+++ b/certbot/cli/verb_help.py
@@ -0,0 +1,112 @@
+"""This module contain help information for verbs supported by certbot"""
+import os
+
+from certbot.cli import (
+    SHORT_USAGE,
+    flag_default
+)
+
+# The attributes here are:
+# short: a string that will be displayed by "certbot -h commands"
+# opts:  a string that heads the section of flags with which this command is documented,
+#        both for "certbot -h SUBCOMMAND" and "certbot -h all"
+# usage: an optional string that overrides the header of "certbot -h SUBCOMMAND"
+VERB_HELP = [
+    ("run (default)", {
+        "short": "Obtain/renew a certificate, and install it",
+        "opts": "Options for obtaining & installing certificates",
+        "usage": SHORT_USAGE.replace("[SUBCOMMAND]", ""),
+        "realname": "run"
+    }),
+    ("certonly", {
+        "short": "Obtain or renew a certificate, but do not install it",
+        "opts": "Options for modifying how a certificate is obtained",
+        "usage": ("\n\n  certbot certonly [options] [-d DOMAIN] [-d DOMAIN] ...\n\n"
+                  "This command obtains a TLS/SSL certificate without installing it anywhere.")
+    }),
+    ("renew", {
+        "short": "Renew all certificates (or one specified with --cert-name)",
+        "opts": ("The 'renew' subcommand will attempt to renew all"
+                 " certificates (or more precisely, certificate lineages) you have"
+                 " previously obtained if they are close to expiry, and print a"
+                 " summary of the results. By default, 'renew' will reuse the options"
+                 " used to create obtain or most recently successfully renew each"
+                 " certificate lineage. You can try it with `--dry-run` first. For"
+                 " more fine-grained control, you can renew individual lineages with"
+                 " the `certonly` subcommand. Hooks are available to run commands"
+                 " before and after renewal; see"
+                 " https://certbot.eff.org/docs/using.html#renewal for more"
+                 " information on these."),
+        "usage": "\n\n  certbot renew [--cert-name CERTNAME] [options]\n\n"
+    }),
+    ("certificates", {
+        "short": "List certificates managed by Certbot",
+        "opts": "List certificates managed by Certbot",
+        "usage": ("\n\n  certbot certificates [options] ...\n\n"
+                  "Print information about the status of certificates managed by Certbot.")
+    }),
+    ("delete", {
+        "short": "Clean up all files related to a certificate",
+        "opts": "Options for deleting a certificate",
+        "usage": "\n\n  certbot delete --cert-name CERTNAME\n\n"
+    }),
+    ("revoke", {
+        "short": "Revoke a certificate specified with --cert-path or --cert-name",
+        "opts": "Options for revocation of certificates",
+        "usage": "\n\n  certbot revoke [--cert-path /path/to/fullchain.pem | "
+        "--cert-name example.com] [options]\n\n"
+    }),
+    ("register", {
+        "short": "Register for account with Let's Encrypt / other ACME server",
+        "opts": "Options for account registration",
+        "usage": "\n\n  certbot register --email user@example.com [options]\n\n"
+    }),
+    ("update_account", {
+        "short": "Update existing account with Let's Encrypt / other ACME server",
+        "opts": "Options for account modification",
+        "usage": "\n\n  certbot update_account --email updated_email@example.com [options]\n\n"
+    }),
+    ("unregister", {
+        "short": "Irrevocably deactivate your account",
+        "opts": "Options for account deactivation.",
+        "usage": "\n\n  certbot unregister [options]\n\n"
+    }),
+    ("install", {
+        "short": "Install an arbitrary certificate in a server",
+        "opts": "Options for modifying how a certificate is deployed",
+        "usage": "\n\n  certbot install --cert-path /path/to/fullchain.pem "
+        " --key-path /path/to/private-key [options]\n\n"
+    }),
+    ("config_changes", {
+        "short": "Show changes that Certbot has made to server configurations",
+        "opts": "Options for controlling which changes are displayed",
+        "usage": "\n\n  certbot config_changes --num NUM [options]\n\n"
+    }),
+    ("rollback", {
+        "short": "Roll back server conf changes made during certificate installation",
+        "opts": "Options for rolling back server configuration changes",
+        "usage": "\n\n  certbot rollback --checkpoints 3 [options]\n\n"
+    }),
+    ("plugins", {
+        "short": "List plugins that are installed and available on your system",
+        "opts": 'Options for for the "plugins" subcommand',
+        "usage": "\n\n  certbot plugins [options]\n\n"
+    }),
+    ("update_symlinks", {
+        "short": "Recreate symlinks in your /etc/letsencrypt/live/ directory",
+        "opts": ("Recreates certificate and key symlinks in {0}, if you changed them by hand "
+                 "or edited a renewal configuration file".format(
+                  os.path.join(flag_default("config_dir"), "live"))),
+        "usage": "\n\n  certbot update_symlinks [options]\n\n"
+    }),
+    ("enhance", {
+        "short": "Add security enhancements to your existing configuration",
+        "opts": ("Helps to harden the TLS configuration by adding security enhancements "
+                 "to already existing configuration."),
+        "usage": "\n\n  certbot enhance [options]\n\n"
+    }),
+]
+
+
+# VERB_HELP is a list in order to preserve order, but a dict is sometimes useful
+VERB_HELP_MAP = dict(VERB_HELP)
diff --git a/certbot/cli/warning.py b/certbot/cli/warning.py
new file mode 100644
index 00000000000..40d630cd414
--- /dev/null
+++ b/certbot/cli/warning.py
@@ -0,0 +1,30 @@
+"""This module warns for usage of deprecated letsencrypt-auto"""
+import os
+import sys
+import logging
+import logging.handlers
+
+from certbot.cli import (
+    cli_command,
+    LEAUTO
+)
+
+logger = logging.getLogger(__name__)
+
+
+def possible_deprecation_warning(config):
+    "A deprecation warning for users with the old, not-self-upgrading letsencrypt-auto."
+    if cli_command != LEAUTO:
+        return
+    if config.no_self_upgrade:
+        # users setting --no-self-upgrade might be hanging on a client version like 0.3.0
+        # or 0.5.0 which is the new script, but doesn't set CERTBOT_AUTO; they don't
+        # need warnings
+        return
+    if "CERTBOT_AUTO" not in os.environ:
+        logger.warning("You are running with an old copy of letsencrypt-auto"
+            " that does not receive updates, and is less reliable than more"
+            " recent versions. The letsencrypt client has also been renamed"
+            " to Certbot. We recommend upgrading to the latest certbot-auto"
+            " script, or using native OS packages.")
+        logger.debug("Deprecation warning circumstances: %s / %s", sys.argv[0], os.environ)
diff --git a/certbot/tests/cli_test.py b/certbot/tests/cli_test.py
index e16a1bdcfb0..4998113f607 100644
--- a/certbot/tests/cli_test.py
+++ b/certbot/tests/cli_test.py
@@ -87,7 +87,7 @@ def write_msg(message, *args, **kwargs): # pylint: disable=missing-docstring,unu
         return output.getvalue()
 
     @test_util.broken_on_windows
-    @mock.patch("certbot.cli.flag_default")
+    @mock.patch("certbot.cli.helpful.flag_default")
     def test_cli_ini_domains(self, mock_flag_default):
         tmp_config = tempfile.NamedTemporaryFile()
         # use a shim to get ConfigArgParse to pick up tmp_config
diff --git a/certbot/tests/helpful_test.py b/certbot/tests/helpful_test.py
new file mode 100644
index 00000000000..2bc2a2014ed
--- /dev/null
+++ b/certbot/tests/helpful_test.py
@@ -0,0 +1,193 @@
+"""Tests for certbot.helpful_parser"""
+import unittest
+
+from certbot.cli import HelpfulArgumentParser
+from certbot.cli import _DomainsAction
+from certbot import errors
+from certbot import constants
+
+
+class TestScanningFlags(unittest.TestCase):
+    '''Test the prescan_for_flag method of HelpfulArgumentParser'''
+    def test_prescan_no_help_flag(self):
+        arg_parser = HelpfulArgumentParser(['run'], {})
+        detected_flag = arg_parser.prescan_for_flag('--help',
+                                                        ['all', 'certonly'])
+        self.assertFalse(detected_flag)
+        detected_flag = arg_parser.prescan_for_flag('-h',
+                                                        ['all, certonly'])
+        self.assertFalse(detected_flag)
+
+    def test_prescan_unvalid_topic(self):
+        arg_parser = HelpfulArgumentParser(['--help', 'all'], {})
+        detected_flag = arg_parser.prescan_for_flag('--help',
+                                                    ['potato'])
+        self.assertIs(detected_flag, True)
+        detected_flag = arg_parser.prescan_for_flag('-h',
+                                                    arg_parser.help_topics)
+        self.assertFalse(detected_flag)
+
+    def test_prescan_valid_topic(self):
+        arg_parser = HelpfulArgumentParser(['-h', 'all'], {})
+        detected_flag = arg_parser.prescan_for_flag('-h',
+                                                    arg_parser.help_topics)
+        self.assertEqual(detected_flag, 'all')
+        detected_flag = arg_parser.prescan_for_flag('--help',
+                                                    arg_parser.help_topics)
+        self.assertFalse(detected_flag)
+
+class TestDetermineVerbs(unittest.TestCase):
+    '''Tests for determine_verb methods of HelpfulArgumentParser'''
+    def test_determine_verb_wrong_verb(self):
+        arg_parser = HelpfulArgumentParser(['potato'], {})
+        self.assertEqual(arg_parser.verb, "run")
+        self.assertEqual(arg_parser.args, ["potato"])
+
+    def test_determine_verb_help(self):
+        arg_parser = HelpfulArgumentParser(['--help', 'everything'], {})
+        self.assertEqual(arg_parser.verb, "help")
+        self.assertEqual(arg_parser.args, ["--help", "everything"])
+        arg_parser = HelpfulArgumentParser(['-d', 'some_domain', '--help',
+                                               'all'], {})
+        self.assertEqual(arg_parser.verb, "help")
+        self.assertEqual(arg_parser.args, ['-d', 'some_domain', '--help',
+                                               'all'])
+
+    def test_determine_verb(self):
+        arg_parser = HelpfulArgumentParser(['certonly'], {})
+        self.assertEqual(arg_parser.verb, 'certonly')
+        self.assertEqual(arg_parser.args, [])
+
+        arg_parser = HelpfulArgumentParser(['auth'], {})
+        self.assertEqual(arg_parser.verb, 'certonly')
+        self.assertEqual(arg_parser.args, [])
+
+        arg_parser = HelpfulArgumentParser(['everything'], {})
+        self.assertEqual(arg_parser.verb, 'run')
+        self.assertEqual(arg_parser.args, [])
+
+
+class TestAdd(unittest.TestCase):
+    '''Tests for add method in HelpfulArgumentParser'''
+    def test_add_trivial_argument(self):
+        arg_parser = HelpfulArgumentParser(['run'], {})
+        arg_parser.add(None, "--hello-world")
+        parsed_args = arg_parser.parser.parse_args(['--hello-world',
+                                                    'Hello World!'])
+        self.assertIs(parsed_args.hello_world, 'Hello World!')
+        self.assertFalse(hasattr(parsed_args, 'potato'))
+
+    def test_add_expected_argument(self):
+        arg_parser = HelpfulArgumentParser(['--help', 'run'], {})
+        arg_parser.add(
+                [None, "run", "certonly", "register"],
+                "--eab-kid", dest="eab_kid", action="store",
+                metavar="EAB_KID",
+                help="Key Identifier for External Account Binding")
+        parsed_args = arg_parser.parser.parse_args(["--eab-kid", None])
+        self.assertIs(parsed_args.eab_kid, None)
+        self.assertTrue(hasattr(parsed_args, 'eab_kid'))
+
+
+class TestAddGroup(unittest.TestCase):
+    '''Test add_group method of HelpfulArgumentParser'''
+    def test_add_group_no_input(self):
+        arg_parser = HelpfulArgumentParser(['run'], {})
+        self.assertRaises(TypeError, arg_parser.add_group)
+
+    def test_add_group_topic_not_visible(self):
+        # The user request help on run. A topic that given somewhere in the
+        # args won't be added to the groups in the parser.
+        arg_parser = HelpfulArgumentParser(['--help', 'run'], {})
+        arg_parser.add_group("auth",
+                                         description="description of auth")
+        self.assertEqual(arg_parser.groups, {})
+
+    def test_add_group_topic_requested_help(self):
+        arg_parser = HelpfulArgumentParser(['--help', 'run'], {})
+        arg_parser.add_group("run",
+                                         description="description of run")
+        self.assertTrue(arg_parser.groups["run"])
+        arg_parser.add_group("certonly", description="description of certonly")
+        with self.assertRaises(KeyError):
+            self.assertFalse(arg_parser.groups["certonly"])
+
+
+class TestParseArgsErrors(unittest.TestCase):
+    '''Tests for errors that should be met for some cases in parse_args method
+    in HelpfulArgumentParser'''
+    def test_parse_args_renew_force_interactive(self):
+        arg_parser = HelpfulArgumentParser(['renew', '--force-interactive'],
+                                           {})
+        arg_parser.add(
+            None, constants.FORCE_INTERACTIVE_FLAG, action="store_true")
+
+        with self.assertRaises(errors.Error):
+            arg_parser.parse_args()
+
+    def test_parse_args_non_interactive_and_force_interactive(self):
+        arg_parser = HelpfulArgumentParser(['--force-interactive',
+                                            '--non-interactive'], {})
+        arg_parser.add(
+            None, constants.FORCE_INTERACTIVE_FLAG, action="store_true")
+        arg_parser.add(
+            None, "--non-interactive", dest="noninteractive_mode",
+            action="store_true"
+        )
+
+        with self.assertRaises(errors.Error):
+            arg_parser.parse_args()
+
+    def test_parse_args_subset_names_wildcard_domain(self):
+        arg_parser = HelpfulArgumentParser(['--domain',
+                                           '*.example.com,potato.example.com',
+                                           '--allow-subset-of-names'], {})
+        # The following arguments are added because they have to be defined
+        # in order for arg_parser to run completely. They are not used for the
+        # test.
+        arg_parser.add(
+            None, constants.FORCE_INTERACTIVE_FLAG, action="store_true")
+        arg_parser.add(
+            None, "--non-interactive", dest="noninteractive_mode",
+            action="store_true")
+        arg_parser.add(
+            None, "--staging"
+        )
+        arg_parser.add(None, "--dry-run")
+        arg_parser.add(None, "--csr")
+        arg_parser.add(None, "--must-staple")
+        arg_parser.add(None, "--validate-hooks")
+
+        arg_parser.add(None, "-d", "--domain", dest="domains",
+                       metavar="DOMAIN", action=_DomainsAction)
+        arg_parser.add(None, "--allow-subset-of-names")
+        # with self.assertRaises(errors.Error):
+        #    arg_parser.parse_args()
+
+    def test_parse_args_hosts_and_auto_hosts(self):
+        arg_parser = HelpfulArgumentParser(['--hsts', '--auto-hsts'], {})
+
+        arg_parser.add(
+            None, "--hsts", action="store_true", dest="hsts")
+        arg_parser.add(
+            None, "--auto-hsts", action="store_true", dest="auto_hsts")
+        # The following arguments are added because they have to be defined
+        # in order for arg_parser to run completely. They are not used for the
+        # test.
+        arg_parser.add(
+            None, constants.FORCE_INTERACTIVE_FLAG, action="store_true")
+        arg_parser.add(
+            None, "--non-interactive", dest="noninteractive_mode",
+            action="store_true")
+        arg_parser.add(None, "--staging")
+        arg_parser.add(None, "--dry-run")
+        arg_parser.add(None, "--csr")
+        arg_parser.add(None, "--must-staple")
+        arg_parser.add(None, "--validate-hooks")
+        arg_parser.add(None, "--allow-subset-of-names")
+        with self.assertRaises(errors.Error):
+            arg_parser.parse_args()
+
+
+if __name__ == '__main__':
+    unittest.main() # pragma: no cover


Code review comments:
diff_hunk: @@ -0,0 +1,467 @@
+"""Certbot command line argument parser"""
+from __future__ import print_function
+import argparse
+import copy
+import glob
+import os
+import sys
+import configargparse
+import six
+import zope.component
+import zope.interface
+
+from zope.interface import interfaces as zope_interfaces
+
+# pylint: disable=unused-import, no-name-in-module
+from acme.magic_typing import Any, Dict, Optional
+# pylint: enable=unused-import, no-name-in-module
+
+from certbot import constants
+from certbot import crypto_util
+from certbot import errors
+from certbot import hooks
+from certbot import interfaces
+from certbot import util
+
+from certbot.display import util as display_util
+
+from certbot.cli import (
path: certbot/cli/helpful.py
text: @user1:
Here also, I think the imports should be done directly from the relevant submodules, instead of adding an indirection to the top level `certbot.cli` package.

diff_hunk: @@ -0,0 +1,51 @@
+"""This is a module that adds configuration to the argument parser regarding
+paths for certificates"""
+import os
+
+from certbot.cli import (
path: certbot/cli/paths_parser.py
text: @user1:
Here also, I think the imports should be done directly from the relevant submodules, instead of adding an indirection to the top level `certbot.cli package`.

diff_hunk: @@ -0,0 +1,537 @@
+"""Certbot command line argument & config processing."""
+# pylint: disable=too-many-lines
+from __future__ import print_function
+import logging
+import logging.handlers
+import argparse
+import sys
+import certbot.plugins.selection as plugin_selection
+from certbot.plugins import disco as plugins_disco
+
+# pylint: disable=unused-import, no-name-in-module
+from acme.magic_typing import Any, Dict, Optional
+# pylint: enable=unused-import, no-name-in-module
+
+import certbot
+from certbot import constants
+
+import certbot.plugins.enhancements as enhancements
+
+
+from certbot.cli.cli_constants import (
+    LEAUTO,
+    old_path_fragment,
+    new_path_prefix,
+    cli_command,
+    SHORT_USAGE,
+    COMMAND_OVERVIEW,
+    HELP_AND_VERSION_USAGE,
+    ARGPARSE_PARAMS_TO_REMOVE,
+    EXIT_ACTIONS,
+    ZERO_ARG_ACTIONS,
+    VAR_MODIFIERS
+)
+
+from certbot.cli.cli_utils import (
+    _Default,
+    read_file,
+    flag_default,
+    config_help,
+    HelpfulArgumentGroup,
+    CustomHelpFormatter,
+    _DomainsAction,
+    add_domains,
+    CaseInsensitiveList,
+    _user_agent_comment_type,
+    _EncodeReasonAction,
+    parse_preferred_challenges,
+    _PrefChallAction,
+    _DeployHookAction,
+    _RenewHookAction,
+    nonnegative_int
+)
+
+# These imports depend on cli_constants and cli_utils.
+from certbot.cli.report_config_interaction import report_config_interaction
+from certbot.cli.warning import possible_deprecation_warning
+from certbot.cli.verb_help import VERB_HELP, VERB_HELP_MAP
+from certbot.cli.group_adder import _add_all_groups
+from certbot.cli.subparsers import _create_subparsers
+from certbot.cli.paths_parser import _paths_parser
+from certbot.cli.plugins_parsing import _plugins_parsing
+
+# These imports depend on some or all of the submodules for cli.
+from certbot.cli.helpful import HelpfulArgumentParser
+
+
+logger = logging.getLogger(__name__)
+
+
+# Global, to save us from a lot of argument passing within the scope of this module
+helpful_parser = None  # type: Optional[HelpfulArgumentParser]
+
+
+def prepare_and_parse_args(plugins, args, detect_defaults=False):  # pylint: disable=too-many-statements
path: certbot/cli/__init__.py
text: @user1:
Since most of the logic has been moved to submodules, I would go to a completely consistent approach here. Why not moving this method also in a dedicated submodule, and import it here? This also apply to the other methods still in `__init_.py`, and would make `certbot.cli` a pure gateway exposing selected objects from its submodules.

diff_hunk: @@ -0,0 +1,97 @@
+"""This is a module that handles parsing of plugins for the argument parser"""
+from certbot.cli import flag_default
path: certbot/cli/plugins_parsing.py
text: @user1:
Here also, I think the imports should be done directly from the relevant submodules, instead of adding an indirection to the top level certbot.cli package.

diff_hunk: @@ -0,0 +1,26 @@
+"""This is a module that reports config option interaction that should be
+checled by set_by_cli"""
+import six
+from certbot.cli import VAR_MODIFIERS
path: certbot/cli/report_config_interaction.py
text: @user1:
Here also, I think the imports should be done directly from the relevant submodules, instead of adding an indirection to the top level certbot.cli package.

diff_hunk: @@ -0,0 +1,75 @@
+"""This module creates subparsers for the argument parser"""
+from certbot import constants
+from certbot import interfaces
+
+from certbot.cli import (
path: certbot/cli/subparsers.py
text: @user1:
Here also, I think the imports should be done directly from the relevant submodules, instead of adding an indirection to the top level certbot.cli package.

diff_hunk: @@ -0,0 +1,112 @@
+"""This module contain help information for verbs supported by certbot"""
+import os
+
+from certbot.cli import (
path: certbot/cli/verb_help.py
text: @user1:
Here also, I think the imports should be done directly from the relevant submodules, instead of adding an indirection to the top level certbot.cli package.

diff_hunk: @@ -0,0 +1,30 @@
+"""This module warns for usage of deprecated letsencrypt-auto"""
+import os
+import sys
+import logging
+import logging.handlers
+
+from certbot.cli import (
path: certbot/cli/warning.py
text: @user1:
Here also, I think the imports should be done directly from the relevant submodules, instead of adding an indirection to the top level certbot.cli package.

diff_hunk: @@ -0,0 +1,193 @@
+"""Tests for certbot.helpful_parser"""
+import unittest
+
+from certbot.cli import HelpfulArgumentParser
path: certbot/tests/helpful_test.py
text: @user1:
Here also, I think the two imports should be done directly from the relevant submodules, instead of adding an indirection to the top level certbot.cli package.

diff_hunk: @@ -24,6 +24,7 @@ Certbot adheres to [Semantic Versioning](https://semver.org/).
   `keyAuthorization` field but will temporarily retry the request with the
   field included if a `malformed` error is received. This fallback will be
   removed in version 0.34.0.
+* cli is now a package split in submodules instead of a whole module.
path: CHANGELOG.md
text: @user1:
After merging from master, this new entry should be moved in the 0.33.0 section.

@author:
I couldn't agree more with what you wrote ! We stopped because the project was over, but we knew we could again split it more. However, having dozens of submodules can also make it a bit hard to understand what cli does in the end when looking at __init.py. I don't think it's happening here, but it should be as atomic as possible and also keeping groups of methods that implement a specific feature.

Again, don't forget to add tests (even though it can be painful to write!), the purpose of this refactoring was to make cli easier to read and easier to test :) But as I said, it could be in a future PR, it might be too much for a single PR.

@user1:
Indeed, tests should be refactored in a later PR. For now, the coverage is the same, so no rush on it.

For this PR, will you have the time to apply the suggestions?

diff_hunk: @@ -0,0 +1,19 @@
+"""This module contains a function to add the groups of arguments for the help
+display"""
+from certbot.cli import VERB_HELP
path: certbot/cli/group_adder.py
text: @user1:
To be consistent with the logic of delegating logic to submodule, I think the import here should be done from the submodule that created `VERB_HELP`, instead of from the top package `certbot.cli`, that in facts import itself from the submodule. It would reduce the indirection depth of imports.