botfriend 0.7.0
A server-side framework that makes it easy to manage artistic bots that post to social media.
License: MIT

# Botfriend

Botfriend is a Python framework for managing a lot of creative bots
that post to a number of different services.

I think the primary features of Botfriend are these:

* Minimal Python coding -- just write the interesting part of your bot.
* Simple configuration based on YAML.
* Easy scheduling of posts.
* Each bot can post to Twitter and/or Mastodon. (Tumblr support is planned.)
* Built-in access to art supplies through [Olipy](https://github.com/leonardr/olipy).

Botfriend is a Python library that runs on a server. If you're not
comfortable with setting up a cron job, or writing Python code, I
recommend you instead check out [Cheap Bots, Done
Quick](http://cheapbotsdonequick.com/) or [Cheap Bots, Toot
Sweet!](https://cheapbotstootsweet.com/), as a simpler way to express
your creativity.

# The Story

I wrote Botfriend to manage about [thirty different Twitter
bots](https://www.crummy.com/features/) that I created. I found myself
constantly copying and pasting, writing the same code over and
over. Every bot does something different, but they all have certain
basic needs: connecting to various services and APIs, deciding when to
post something, managing backlogs of content, and so on. There's no
reason each bot needs its own version of this code. The only part of a
bot that needs new code is the creative bit.

My other big problem was, I've come to dislike Twitter. It's a great
platform for creative bots, but every time I created a bot, I felt
guilty about increasing the value of an platform I think is making the
world worse. (Also, Twitter has started suspending my bots for no reason.)

I didn't want to give up my botmaking hobby, so I started
investigating the world of [Mastodon](https://joinmastodon.org/)
bots. This created another problem: it's a big pain to rewrite thirty
bots to post to a different service. If I was going to do that much
work, I wanted the end product to be a reusable library that could
save everyone time.

So I went through my thirty bots, rewrote everything, and moved all of
the reusable code into Botfriend. Now my bots are a lot smaller and
easier to manage. All of the tedious code is in one place, and I can
focus on the fun part of bot-writing.

Consider a bot like [A Dull Bot](https://botsin.space/@ADullBot)
([source](https://github.com/leonardr/botfriend/tree/master/bots.sample/a-dull-bot)). Creating
this bot was a fair amount of work. But all of the work went into the
fun part: creating an accurate software model of the typewriter from
_The Shining_. There's no code for making sure the bot posts once an
hour, or for pushing the typewritten text through the Twitter or
Mastodon APIs. Botfriend takes care of all that stuff.

If you want to save code on your own bot projects, port your bots from
Twitter to Mastodon, or just expand the reach of your bots, I hope
you'll consider Botfriend.

# Setup

I recommend you run Botfriend in a Python virtual environment. Here's
how to create a virtual environment called `env` and install Botfriend
into it.

```
$ virtualenv env
$ source env/bin/activate
$ pip install botfriend
```

You'll interact with Botfriend exclusively through command-line
scripts. From this point on I'll be giving lots of example command
lines. All of my examples assume you've entered the Botfriend virtual
environment by running this command beforehand:

```
$ source env/bin/activate
```

# A simple example: Number Jokes

By default, Botfriend expects you to put the source code for the bots
in a directory `bots/`, located in the same directory as your virtual
environment. So if your virtual environment is located in
`/home/myusername/botfriend/env`, Botfriend will expect your bots to
live underneath `/home/myusername/botfriend/bots`.

The Botfriend database itself will be stored in the bot directory as
`botfriend.sqlite`.

If you want to store your Botfriend data somewhere other than `bots/`,
every Botfriend script takes a `--config` argument that points to your
bot directory. But most of the time, `bots/` is fine.

Each individual bot will live in a subdirectory of your bot directory,
named after the bot. Let's get started with a simple example, called
`number-jokes`.

```
$ mkdir bots
$ mkdir bots/number-jokes
```

Each bot needs to contain two special files: `__init__.py` for source
code and `bot.yaml` for configuration.

## `__init__.py`: Coming up with the joke

Imagine walking up to to a comedian and saying "Tell me a joke!" A
human comedian probably won't appreciate it, but this is what bots
live for. For a Botfriend bot, `__init__.py` is where the comedian
comes up with their jokes.

To get started, we'll make a simple bot that makes up observational
humor about numbers.

To get started, open up `bots/number-jokes/__init__.py` in a text
editor and write this in there:

```
import random
from botfriend.bot import TextGeneratorBot

class NumberJokes(TextGeneratorBot):

    def generate_text(self):
        """Tell a joke about numbers."""
        num = random.randint(1,10)
        arguments = dict(
            num=num,
            plus_1=num+1,
            plus_3=num+3
        )
        setup = "Why is %(num)d afraid of %(plus_1)d? "
        punchline = "Because %(plus_1)d ate %(plus_3)d!"
        return (setup + punchline) % arguments

Bot = NumberJokes
```

Botfriend provides a lot of utilities to help you write a good
`__init__.py`, but there's only one hard-and-fast rule: by the end of
the file, you have to have a class called `Bot`. The Botfriend scripts
are going to load your `Bot` class, instantiate it, and use it to
do... whatever the bot does.

Some bots do a lot of work to come up with a single "joke". They might
draw pictures, do database queries, make API calls, all sorts of
complicated things. As befits an example, `NumberJokes` here does
almost no work. It just picks a random number and puts it into a string.

## `bot.yaml`: Telling the joke

Like most comedians, bots are constantly coming up with jokes. But if
no one ever hears the joke, what's the point? The `bot.yaml` file
explains how a Botfriend bot should _tell_ its jokes to the public.

Open up the file `bots/number-jokes/bot.yaml` and write this in there:

```
name: "Number Jokes"
schedule: 60
publish:
    file:
      filename: "number-jokes.txt"
```

Like `__init__.py`, `bot.yaml` can get really complicated, but most of
the time it's pretty simple. This file is saying:

* The name of the bot is "Number Jokes".

* The bot should 'tell a joke' once an hour.

* This bot tells jokes by writting them to the file
  `number-jokes.txt`. (This is relative to the bot directory, so it's going
  to be in `bots/number-jokes/number-jokes.txt`.)

Now you're ready to make your bot tell some jokes, using some basic
Botfriend scripts.

# The basic scripts

## `botfriend.post`

The `botfriend.post` script makes each of your bots come up with a
joke and tell it. Run it now:

```
$ botfriend.post
# Number Jokes | file | Published 2019-01-20 | Why is 4 afraid of 5… 
```

Now look at the file you configured in `bot.yaml`. You told Number
Jokes to post its jokes to `bots/number-jokes/number-jokes.txt`. That file
didn't exist before you ran `botfriend.post`, but now it does exist,
and it's got a joke in it:

```
$ cat bots/number-jokes/number-jokes.txt
2019-01-20 10:23:44 | Why is 4 afraid of 5? Because 5 ate 7!
```

Hilarious, right? You'll be running this script a lot, probably as
part of an automated process. On my site I run `botfriend.post` every
five minutes. (I show an example of how to do this at the end of this
document.)

If your bot isn't scheduled to tell a joke, `botfriend.post` will do
nothing. Run it again now -- nothing will happen.

```
$ botfriend.post
```

Number Jokes told a joke the first time you ran it, and (as you told
it in `bot.yaml`) it's only supposed to tell one joke an hour. So, no
new joke.

If you were to wait an hour and run `botfriend.post` again, you'd get
another joke. But don't wait -- keep going through this tutorial!

## Running a script on just one bot

By specifying a directory name on the command line, you can make
`botfriend.post` (and most other Botfriend scripts) operate on just
one bot, not all of your bots. Right now, it doesn't make a
difference, because you only have one bot, but here's how to do it:

```
$ botfriend.post number-jokes
```

## Forcing a bot to post

You can use `--force` to make a bot tell a joke even if its schedule
wouldn't normally allow it.

```
$ botfriend.post number-jokes --force
# LOG 2019-01-20 | Number Jokes | file | Published 2019-01-20 | Why is 9 afraid of 10… 
```

Now `bots/number-jokes/number-jokes.txt` contains two jokes.

```
$ cat bots/number-jokes/number-jokes.txt
2019-01-20 10:23:44 | Why is 4 afraid of 5? Because 5 ate 7!
2019-01-20 10:26:12 | Why is 9 afraid of 10? Because 10 ate 11!
```

## `botfriend.dashboard`

This script is good for getting an overview of your bots. It shows
what they've been up to lately and when they're scheduled to post again.

```
$ botfriend.dashboard number-jokes
# Number Jokes | Most recent post: Why is 9 afraid of 10? Because 10 ate 12!
# Number Jokes | file posted 0m ago (2019-01-20 10:26:12)
# Number Jokes | Next post in 59m
```

## `botfriend.bots`

If you have a lot of bots, it can be annoying to remember all their
names. The `botfriend.bots` script just lists all the bots known to
Botfriend.

```
$ botfriend.bots
# number-jokes
```

Still only one bot so far.

## `botfriend.test.stress`

It's difficult to test a bot that does random things. You might have a
bug that makes the bot crash only one time in a thousand. Or your bot
might never crash, but sometimes take a long time to run.

This is why we have the `botfriend.test.stress` script, which asks a
bot to come up with ten thousand jokes in a row. The jokes aren't
published anywhere; the goal is just to give a good test of all the
possible cases that might happen inside your bot.

Since Number Jokes is really simple, it can generate ten thousand jokes
with no problem, although some of them are repeats:

```
$ botfriend.test.stress number-jokes
# Why is 2 afraid of 3? Because 3 ate 5!
# Why is 7 afraid of 8? Because 8 ate 10!
# Why is 1 afraid of 2? Because 2 ate 4!
# Why is 4 afraid of 5? Because 5 ate 7!
# Why is 4 afraid of 5? Because 5 ate 7!
# Why is 7 afraid of 8? Because 8 ate 10!
# ... etc. etc. ...
```

If you've got a complicated bot, it can be a good idea to run
`botfriend.test.stress` on it a couple of times before using it for real.

# How to publish

There are a few more interesting features of Botfriend, but let's take
a minute to talk about the boring features. It's easy to make a bot
write its posts to a file, but nobody's going to see that. What you
really need is to get some Twitter or Mastodon credentials. (Specific
instructions are below.)

Once you have some credentials, open up your bot's `bot.yaml` file,
add your credentials to the `publish` configuration setting. This will
give your bot additional ways to publish its posts.

Here's an example. This is what the configuration for Number Jokes
would look like if it had Twitter and Mastodon connections set up, in
addition to writing everything to a file.

```
name: Number Jokes
schedule: 60
publish:
  file:
    filename: number-jokes.txt
  mastodon:
    api_base_url: 'https://botsin.space/'
    client_id: cc13bf3de67fb399475c315e4a9bf5dd4dfb7ea0f3a521fca72a9c8bf02075ab
    client_secret: 0946d2634d7b6aa1ea93af4b183fccf14e9df2e2b55db8fcdb0c8a5f267ff312
    access_token: c76eb18c5c0dc7c1fe09b53ac175b3b9ed081b0e43ea4d60e94ee721b83c1eda
  twitter:
    consumer_key: t7CfbbNLB3jfoAKI
    consumer_secret: 2teOyqqgFpFpytFanuOXzfjvR3vEmYH3
    access_token: 3341062559-SbUlEDFCDn6k6vHHDWGwqlK0wyZ0fKRegaZMyS9lwBa4L5VXY5fdl
    access_token_secret: ALc2CPkkrSBf33swYluxEgdC0GNueQK3x6D4pEr8GGDpqrmed
```

(These credentials won't work -- I made them up to resemble real
Twitter and Mastodon credentials.)

## Publish to a file

This is the simplest publication technique, and it's really only good
for testing and for keeping a log. The `file` publisher takes one
configuration setting: `filename`, the name of the file to write to.

```
publish:
    file:
        filename: "anniversary.txt"
```

## Publish to Twitter

To get your bot on Twitter, you need to create a Twitter account for
the bot, log in as the bot, and then get four different values:
`consumer_key`, `consumer_secret`, `access_token` and
`access_token_secret`. These four values, when inserted into
`bot.yaml`, give you the ability to post to a specific Twitter account
using the Twitter API.

Getting those four values can be tricky, and Twitter periodically
changes up the rules and the processes. [Bot Wiki links to various
tutorials](https://botwiki.org/resource/tutorial/how-to-make-a-twitter-bot-the-definitive-guide/) for setting this stuff up.

Once you have these four values, put them into `bot.yaml`, and your bot
will be able to post to its Twitter account.

## Publish to a Mastodon instance

To connect your bot to Mastodon, you create a Mastodon account for the
bot, log in as the bot, and then get four values.

First, `api_base_url`-- this is easy, it's just the URL to the
Mastodon instance you used to create the account. I like to use
[botsin.space](https://botsin.space/), a Mastodon instance created
especially for bots.

Then you need to get `client_id`, `client_secret`, and `access_token`.
You can get these values by logging in as your bot, going to the
Settings page, clicking "Development", and creating a new
application. (If that's not working for you, try [Darius Kazemi's
instructions](https://tinysubversions.com/notes/mastodon-bot/index.html).)

Once you have these four values, put them into `bot.yaml`, and your bot
will be able to post to its Mastodon account.

Okay, now back to the cool bots you can write with Botfriend.

## `botfriend.test.publisher`: test your publishing credentials

The `botfriend.test.publisher` script tries out all of your bots'
publishing credentials to make sure they work. If a bot is having
trouble posting, the problem will show up here.

For every bot with a publishing technique that works, you'll get a
line that starts with `GOOD`. For every publishing technique that's
broken, you'll get a line that starts with `FAIL`.

In this example, writing to a file works fine, but since the Twitter
and Mastodon credentials are made up, Twitter and Mastodon won't
actually accept them.

```
$ botfriend.test.publisher
# GOOD Number Jokes file
# FAIL Number Jokes twitter: [{u'message': u'Bad Authentication data.', u'code': 215}]
# FAIL Number Jokes mastodon: {u'error': u'The access token is invalid'}
```

# Bots that keep a backlog: Boat Names

Some comedians can come up with original jokes on the fly, over and
over again. Others keep a Private Joke File: a list of jokes assembled
ahead of time which they can dip into as necessary.

Instead of writing a bunch of generator code in a Botfriend bot, you
can generate a _backlog_ of posts, however you like. It's easy to
create a bot that simply posts items from its backlog, in order, one
at a time.

If your style is more writing than programming, you can just write the
backlog in a text editor. This way you can create a Botfriend bot
without writing any code at all.

Let's make a simple backlog bot that posts interesting names for
boats, taken from the website [Ten Thousand Boat
Names](http://www.10000boatnames.com/). (What I'm about to describe is
exactly how my real bot [Boat Names](https://botsin.space/@BoatNames)
works.)

First, make a directory for the bot:

```
$ mkdir bots/boat-names
```

This bot is so simple that you don't need any code to program its
behavior. Just create an empty `__init__.py` file, so that Botfriend
knows this is a bot and not some random directory.

```
$ touch bots/boat-names/__init__.py
```

Just like Number Jokes, Boat Names needs a `bot.yaml` to tell it where
to post and how often. Create `bots/boat-names/bot.yaml` and put this
text in there:

```
name: Boat Names
publish:
    file: boat-names.txt
schedule:
    mean: 480
    stdev: 15
```

The schedule here is a little different than in the first example
bot. The first example's posts will come exactly one hour apart. This
bot posts every eight hours (480 minutes), _on average_, but there is
some random variation--usually up to fifteen or thirty minutes in
either direction.

Now, running `botfriend.bots` will list both of your bots.

```
$ botfriend.bots
# boat-names
# number-jokes
```

Running `botfriend.post` will tell both bots to post something if they
want, but Boat Names can never post anything, because it has no
backlog and no logic for generating new posts. It can't come up with
its own jokes -- you have to help it.

## `botfriend.backlog.load`

The `botfriend.backlog.load` script lets you add items to a bot's
backlog from a file. The simplest way to do this is with a text file
containing one post per line.

Let's create a backlog file. This can go anywhere, but I
recommend keeping it in the same directory as the rest of the bot, in
case something goes wrong and you need to recreate it. Open up a file
`bots/boat-names/backlog.txt` and put a few boat names in it:

```
Honukele
LA PARISIENNE
Stryss
Cozy Cat
Hull # 14
Always On Vacation
Sea Deuce
Bay Viewer
Tanden
Clean Livin'
Goodnight Moon
SPECIAL OCASSION
Innocent Dream
```

Now you can load the backlog:

```
$ botfriend.backlog.load boat-names --file=bots/boat-names/backlog.txt
# LOG | Backlog load script | Appended 13 items to backlog.
# LOG | Backlog load script | Backlog size now 13 items
```

Once there are items in the backlog, `botfriend.post` will work:

```
# botfriend.post
# LOG | Boat Names | file | Published 2019-01-20 03:15 | Honukele
```

## `botfriend.backlog.show`

The `botfriend.backlog.show` script will summarize a bot's current
backlog. It'll show you how many items are in the backlog and what's
coming up next.

```
$ botfriend.backlog.show boat-names
# Boat Names | 12 posts in backlog
# Boat Names | LA PARISIENNE
```

## `botfriend.backlog.clear`

The `botfriend.backlog.clear` script will completely erase a bot's
backlog.

```
$ bin/backlog.clear boat-names
# Boat Names | About to clear the backlog for Boat Names.
# Boat Names | Sleeping for 2 seconds to give you a chance to Ctrl-C.

$ bin/backlog.show boat-names
#  Boat Names | No backlog.
```

# Bots that keep state: Web Words

Sometimes a bot needs to do something that takes a long time, or
something that might be annoying if it happened
frequently. Botfriend allows this difficult or annoying thing to be
done rarely. The results are stored in the bot's _state_ for later
reference.

Let's create one more example bot. This one's called "Web Words". Its
job is to download random web pages and pick random phrases from them.

```
$ mkdir bots/web-words
```

We're going to split the "download a random web page" part of the bot
from the "pick a random phrase" part. The "pick a random phrase" part
will run every time the bot is asked to post something. The "download
a random web page" part will only run once a day, because it involves
making a bunch of HTTP requests to random domain names. But once you
have a web page downloaded, it's quick and easy to pull a random chunk
out of it.

This time let's start with the `bot.yaml` file:

```
name: "Web Words"
schedule: 60
state_update_schedule: 1440
publish:
    file:
      filename: "web-words.txt"
```

This bot will post according to its `schedule`, once an hour (60
minutes). But there's another thing that's going to happen once a day
(every 1440 minutes): a "state update".

Here's the code for Web Words. Put this in
`bots/web-words/__init__.py`:

```
import random
import re
from olipy import corpora
import requests
from botfriend.bot import TextGeneratorBot

class WebWords(TextGeneratorBot):
    """A bot that pulls random words from a random webpage."""

    def update_state(self):
        """Choose random domain names until we find one that hosts a web page
        larger than ten kilobytes.
        """
        new_state = None
        while not new_state:

            # Make up a random URL.
            word = random.choice(corpora.words.english_words['words'])
            domain = random.choice(["com", "net", "org"])
            url = "http://www.%s.%s/" % (word, domain)

            try:
                self.log.info("Trying to get new state from %s" % url)
                response = requests.get(url, timeout=5)
                potential_new_state = response.content
                if len(potential_new_state) < 1024 * 10:
                    # This is probably a generic domain parking page.
                    self.log.info("That was too small, trying again.")
                    continue
                new_state = response.content
                self.log.info("Success!")
            except Exception as e:
                self.log.info("That didn't work, trying again.")
        return new_state

    def generate_text(self):
        """Choose some words at random from a webpage."""
        webpage = self.model.state

        # Choose a random point in the web page that's not right at the end.
        total_size = len(webpage)
        near_the_end = int(total_size * 0.9)
        starting_point = random.randint(0, near_the_end)

        # Find some stuff in the webpage that looks like words, rather than HTML.
        some_words = re.compile("([A-Za-z\s]{10,})")
        match = some_words.search(webpage[starting_point:])

        if not match:
            # Because we didn't find anything, we're choosing not to post
            # anything right now.
            return None
        data = match.groups()[0].strip()
        return data

Bot = WebWords
```

The first time you tell Botfriend to post something for this bot,
Botfriend will call the `update_state()` method. This method may try
several times to find a web page it can use, but it will eventually
succeed.

```
$ botfriend.post web-words
Web Words | Trying to get new state from http://www.stenographical.com/
Web Words | That was too small, trying again.
Web Words | Trying to get new state from http://www.bronchologic.org/
Web Words | That didn't work, trying again.
Web Words | Trying to get new state from http://www.dentonomy.org/
Web Words | That was too small, trying again.
Web Words | Trying to get new state from http://www.crummy.com/
Web Words | Success!
Web Words | file | Published 2019-01-10 01:45 | e experimental group
```

Once the state is in place, running `botfriend.post` again won't
download a whole new web page every time. Instead, Web Words will
choose another random string from the webpage it's already downloaded.

```
$ botfriend.post web-words --force
Web Words | file | Published 2019-01-10 01:46 an old superstition
```

This bot's state expires in one day (this was set in its
`bot.yaml`). 24 hours after `update_state()` is called for the first
time, running `botfriend.post` will cause Botfriend to call that
method again. A brand new web page will be downloaded, and for the
next 24 hours all of the Web Words posts will come from that new web page.

## `botfriend.state.show` - Showing the state

This script simply prints out a bot's current state.

```
$ botfriend.state.show web-words
```

## `botfriend.state.refresh` - Refreshing the state

You can use this script to forcibly refresh a bot's state by calling
`update_state()`, even if the bot's configured `state_update_schedule`
says it's not time to call that method yet.

```
$ botfriend.state.refresh web-words
# Web Words | Trying to get new state from http://www.choristoblastoma.org/
# ...
```

## `botfriend.state.set` - Setting the state to a specific value

You can use this script to set a bot's state to a specific value,
rather than setting the state by calling the `update_state()`
method. Here, instead of telling Web Words to pick random strings from
a web page, we're telling it to pick random strings from its own
source code.

```
$ bin/state.set web-words --file=bots/web-words/__init__.py

$ bin/post web-words --force
Web Words | file | Published 2019-01-21 1:56 | olipy import corpora
```

## `botfriend.state.clear` - Clearing the state

This script will completely erase a bot's script, making it as though
`update_state()` has never been called.

```
$ bin/state.clear web-words
```

# More examples

The [the `botfriend` source
repository](https://github.com/leonardr/botfriend/) includes complete
source code for about ten bots, including the three covered in this
document and several actual bots that I run. To try them out, check
out the repository and copy the contents of its `bots.sample`
directory into your `bots` directory.

```
$ git clone git@github.com:leonardr/botfriend.git
$ cp -r botfriend/bots.sample/* bots
$ ls bots
# a-dull-bot   boat-names         frances-daily   postcards
# ama          botfriend.sqlite   __init__.py     roller-derby
# anniversary  crowd-board-games  link-relations  serial-entrepreneur
# best-of-rhp  euphemism          number-jokes    web-words
```

Every bot directory contains a `README.md` file explaining how that
bot works and which special features of Botfriend (if any) it uses.

Here are the example bots:

* [A Dull
Bot](https://github.com/leonardr/botfriend/tree/master/bots.sample/a-dull-bot) - A simple text generation bot.
* [I Am A
Bot. AMA!](https://github.com/leonardr/botfriend/tree/master/bots.sample/ama) - A bot that keeps complex state for the sake of not repeating a joke.
* [Anniversary
Materials](https://github.com/leonardr/botfriend/tree/master/bots.sample/anniversary) - A text generation bot that uses a lot of different types of input.
* [Best of
RHP](https://github.com/leonardr/botfriend/tree/master/bots.sample/best-of-rhp) - A Twitter-specific bot that does nothing but selectively retweet another account.
* [Boat Names](https://github.com/leonardr/botfriend/tree/master/bots.sample/boat-names) - A simple bot that posts from a backlog. The second example bot described in this document.
* [Crowd Board
Games](https://github.com/leonardr/botfriend/tree/master/bots.sample/crowd-board-games) - A bot that parses an RSS feed and creates a post for every entry.
* [Euphemism
Bot](https://github.com/leonardr/botfriend/tree/master/bots.sample/euphemism) - A text generation bot that builds its posts from a grammar.
* [Frances Daily](https://github.com/leonardr/botfriend/tree/master/bots.sample/frances-daily) - A bot whose posts are scheduled for specific dates and times, rather than randomly or every-so-often. On some days, there are no posts at all.
* [Junk Mail](https://github.com/leonardr/botfriend/tree/master/bots.sample/junkmail) - A bot that keeps track of new additions to a collection on Internet Archive, and posts randomly selected pages from random texts in that collection.
* [Link Relations](https://github.com/leonardr/botfriend/tree/master/bots.sample/link-relations) - A bot that periodically scrapes a web page and posts about anything new it finds.
* [Number Jokes](https://github.com/leonardr/botfriend/tree/master/bots.sample/number-jokes) - The first example bot described in this help document, a simple text generator bot.
* [Podcast Roulette](https://github.com/leonardr/botfriend/tree/master/bots.sample/podcast) - A bot that generates an RSS podcast feed made up of episodes from other podcasts.
* [Roy's
Postcards](https://github.com/leonardr/botfriend/tree/master/bots.sample/postcards) - A bot that posts images as well as text.
* [Deathbot
3000](https://github.com/leonardr/botfriend/tree/master/bots.sample/roller-derby) - A backlog-based bot that loads its backlog in a custom format and formats it dynamically, rather than loading in strings and posting the strings.
* [Serial
Entrepreneur](https://github.com/leonardr/botfriend/tree/master/bots.sample/serial-entrepreneur) - A complex text generator bot.
* [Web Words](https://github.com/leonardr/botfriend/tree/master/bots.sample/web-words) - The third example bot described in this help document. A bot that keeps randomly selected web pages as state.

# Posting on a regular basis

Once you have a few bots, you'll need to run the `botfriend.post` script
regularly to keep new content flowing. The best way to do this is to
set up a cron job to schedule the `botfriend.post` script to run every few
minutes. Don't worry about posting too often. Bots that need to post
something will post when they're ready. Bots that don't need to post
anything right when `botfriend.post` is run, will be quiet, and bide their time.

Here's what my cron script looks like:

```
#!/bin/bash
source $HOME/scripts/botfriend/env/bin/activate
botfriend.post
```

Here's how I use a cron job to run it every five minutes

```
*/5 * * * * /home/leonardr/scripts/botfriend/cron 2> /home/leonardr/scripts/botfriend_err
```

Any errors that happen during the run are appended to a file,
`botfriend_err`, which I can check periodically.

That's pretty much it. The rest of this document is just talking about
some advanced features of Botfriend, which you probably won't need
your first time out.

# Sophisticated configuration

Let's take another look at the `bot.yaml` file for the "Number Jokes" bot:

```
name: Number Jokes
schedule: 60
publish:
  file:
    filename: number-jokes.txt
```

The `name` option should be self-explanatory -- it's the human-readable name of
the bot. Now let's take a detailed look at the other two options.

## `schedule`

The `schedule` configuration option controls how often your bot should
post. There are basically three strategies.

1. Set `schedule` to a number of minutes. (This is what Number Jokes
does.) Your bot will post at exact
intervals, with that number of minutes between posts.
2. Give `schedule` a `mean` number of minutes. Your bot will post at
randomly determined intervals, with _approximately_ that number of
minutes between posts, but with a fair amount of random variation.
3. To fine-tune the randomness, you can specify a `stdev` to go along
with the mean. This sets the standard deviation used when calculating
when the next post should be. Set it to a low number, and posts will
nearly `mean` minutes apart. Set it to a high number, and the posting
schedule will vary widely.

You can omit `schedule` if your bot schedules all of its posts ahead
of time (like [Frances
Daily](https://github.com/leonardr/botfriend/tree/master/bots.sample/frances-daily)
does).

### `state_update_schedule`

There's a related option, `state_update_schedule`, which you only need
to set if your bot keeps internal state, like Web Words does. This
option works the same way as `schedule`, but instead of controlling
how often the bot should post, it controls how often your
`update_state()` method is called.


## Other configuration settings

Certain types of bots have other specific configuration settings. A
subclass of `RetweetBot`, like [Best of
RHP](https://github.com/leonardr/botfriend/tree/master/bots.sample/best-of-rhp),
will use a special configuration setting called `retweet-user`. This
controls which Twitter account the bot retweets. [Podcast Roulette](https://github.com/leonardr/botfriend/tree/master/bots.sample/podcast) has a number of configuration settings like `description` that are copied into the RSS feed.

Your bot can define its own custom configuration options--the
configuration object is parsed as YAML and passed into the `Bot`
constructor as the `config` argument. You can look in there and pick
out whatever information you want.

## Defaults

If you put a file called `default.yaml` in your Botfriend directory
(next to `botfriend.sqlite`), all of your bots will inherit the values
in that file.

Almost all my bots use the same Mastodon and Twitter client keys (but
different application keys), and all my Mastodon bots are hosted at
botsin.space. I keep these configuration settings in `default.yaml` so
I don't have to repeat them in every single `bot.yaml` file. My
`default.yaml` looks like this:

```
publish:
  mastodon: {api_base_url: 'https://botsin.space/', client_id: a, client_secret: b}
  twitter: {consumer_key: c, consumer_secret: d}
```

This way, inside a given `bot.yaml` file, I only have to fill in the
information that's not specified in `default.yaml`:

```
name: My Bot
publish:
 mastodon:
  access_token: efg
 twitter:
  access_token: hij
  access_token_secret: klm
schedule:
 mean: 120
```

## Programmatic access to an API

Sometimes you'll need to use a site's API for more than just posting
to the site. Every bot has a number of publishers configured through
its `publish` settings, and the corresponding `Publisher objects are
available from inside a `Bot` as `self.publishers`. Once you have a
`Publisher` object, the raw API client will always be available as
`Publisher.api`.

See the [`IAmABot`
constructor](https://github.com/leonardr/botfriend/blob/master/bots.sample/ama/__init__.py)
for an example. This bot needs a Twitter API client to get its data,
so it looks through `self.publishers` until it finds the Twitter
publisher, and grabs its `.api`, storing it for later.

# Conclusion

There are a lot of features of Botfriend that I've barely touched or
not mentioned at all: bots that retweet other Twitter accounts, bots
that get their posts by scraping a web page for their content, scripts
for republishing posts that weren't posted properly the first time.

But the features I've covered are the main ones you need to get
started and to see the power of Botfriend. I hope you enjoy it!