Repository: certbot/certbot

Issue:
certbot --help renew doesn't explain `--cert-name`
## My operating system is (include version):

debian 9.0

## I installed Certbot with (certbot-auto, OS package manager, pip, etc):

certbot-auto

## I ran this command and it produced this output:

```
$ certbot-auto --help renew
```
```
usage:

  certbot renew [--cert-name NAME] [options]

optional arguments:
  -h, --help            show this help message and exit
  -c CONFIG_FILE, --config CONFIG_FILE
                        path to config file (default: /etc/letsencrypt/cli.ini
                        and ~/.config/letsencrypt/cli.ini)

renew:
  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.

  --dry-run             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. Note: 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. (default: False)
  --force-renewal, --renew-by-default
                        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. (default: False)
  --allow-subset-of-names
                        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.
                        (default: False)
  -q, --quiet           Silence all output except errors. Useful for
                        automation via cron. Implies --non-interactive.
                        (default: False)
  --debug-challenges    After setting up challenges, wait for user input
                        before submitting to CA (default: False)
  --preferred-challenges PREF_CHALLS
                        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. (default: [])
  --pre-hook PRE_HOOK   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. (default: None)
  --post-hook POST_HOOK
                        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. (default: None)
  --deploy-hook DEPLOY_HOOK
                        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" (default: None)
  --disable-hook-validation
                        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)
```

## Certbot's behavior differed from what I expected because:

It's true that the usage/syntax line says:
```
  certbot renew [--cert-name NAME] [options]
```

but the arguments are documented starting with:
```
  --dry-run             Perform a test run of the client, obtaining test
```
and `--cert-name` isn't among them.


Discussion:

Resolving patch:
diff --git a/certbot/cli.py b/certbot/cli.py
--- a/certbot/cli.py
+++ b/certbot/cli.py
@@ -897,7 +897,7 @@ def prepare_and_parse_args(plugins, args, detect_defaults=False):  # pylint: dis
              "specified or you already have a certificate for the same "
              "domains. (default: Ask)")
     helpful.add(
-        [None, "run", "certonly", "manage", "delete", "certificates"],
+        [None, "run", "certonly", "manage", "delete", "certificates", "renew"],
         "--cert-name", dest="certname",
         metavar="CERTNAME", default=None,
         help="Certificate name to apply. This name is used by Certbot for housekeeping "


Test patch: