Err is a plugin based chatbot designed to be easily deployable, extensible and maintainable. It allows you to start scripts interactively from your chatrooms for any reason: random humour, starting a build, monitoring commits, triggering alerts... The possibilities are endless.

It is written and extensible in Python, and, where possible, uses external libraries instead of reinventing the wheel. We use yapsy for plugin management, jinja2 for templating and bottle as a micro web framework with rocket providing the built-in webserver to power it. Additionally, sleekxmpp and irc are used for the XMPP and IRC backends and six is used for Python 2.7 compatibility.

Err is available as open source software under the GPL3 license.

Err has a google plus community, please feel free to mention it with +err if you need support, have any questions or wish to share some of your creations. If you have a bug to report or wish to request a feature, please log these on it's github page.

We strongly encourage you to share your creations. The only thing you have to do to make your new plugin available to Err installations is to provide a Git url pointing to it. Or, if you feel your new feature could fit as a part of an existing plugin, please feel free to open a pull request for it on github.

Main features:

• XMPP support: Tested with Google Talk, Hipchat, Openfire and Jabber but should be compatible with any standard XMPP server
• CampFire support
• Basic IRC support
• Multi User Chatroom (MUC) support
• A dynamic plugin architecture: Bot admins can install/uninstall/update/enable/disable plugins dynamically just by chatting with the bot
• Advanced security/access control features (see below)

Included:

• A !help command that dynamically generates documentation for commands using the docstrings in the plugin source code
• A per-user command history system where users can recall previous commands
• The ability to proxy and route one-to-one messages to MUC so it can enable simpler XMPP notifiers to be MUC compatible (for example the Jira XMPP notifier)
• Local text and graphical consoles for testing and development

Administration and Security:

• Can be setup so a restricted list of people have administrative rights
• Fine-grained access controls may be defined which allow all or just specific commands to be limited to specific users and/or rooms
• Plugins may be hosted publicly or privately and dynamically installed (by admins) via their Git url
• Plugins can be configured directly from chat (no need to change setup files for every plugin)
• Configs can be exported and imported again with two commands (!export and !import respectively)
• Technical logs can be logged to file and inspected from the chat or optionally be logged to Sentry

An extensive framework for writing custom plugins:

• Writing new plugins has a really low learning curve (see below)
• Graphical and text development consoles allow for fast development roundtrips
• Plugins get out of the box support for subcommands
• We provide an automatic persistence store per plugin
• There's really simple webhooks integration
• As well as a polling framework for plugins
• An easy configuration framework
• A test backend for unittests for plugins which can make assertions about issued commands and their responses
• And a templating framework to display fancy HTML messages. Automatic conversion from HTML to plaintext when the backend doesn't support HTML means you don't have to make seperate text and HTML versions of your command output yourself

Err runs under Python 2.7 as well as Python 3.3+ on Linux, Windows and Mac.

You need to have registered a user for the bot to use on the XMPP or IRC server that you wish to run Err on. A lot of plugins use multi user chatrooms (MUC) as well, so it is recommended (but not required) to have a least one MUC for Err to use as well.

Err may be installed directly from PyPi using pip (easy_install works too) by issuing:

pip install err

Or if you wish to try out the latest, bleeding edge version:

pip install https://github.com/gbin/err/archive/master.zip

However, in these cases, installing into a dedicated virtualenv is recommended.

On some distributions, Err is available as a package via your usual package manager. In these cases, it is generally recommended to use your distribution's package instead of installing from PyPi.

Extra dependencies

requirements.txt lists only the bare minimum list of dependencies needed to run Err. Depending on the backend you choose, additional requirements need to be installed.

For the XMPP based backends you must also install:

sleekxmpp
pyasn1
pyasn1-modules
dnspython3  # dnspython for Python 2.7

For the IRC backend, you must install:

irc

Configuration

After installing Err, you must create a data directory somewhere on your system where config and data may be stored. Find the installation directory of Err, then copy the file <install_directory>/errbot/config-template.py to your data directory as config.py

(If you installed Err via pip, the installation directory will most likely be /usr/lib64/python<python_version_number>/site-packages/errbot)

Read the documentation within this file and edit the values as needed so the bot can connect to your chosen XMPP or IRC server.

Starting the daemon

The first time you start Err, it is recommended to run it in foreground mode. This can be done with:

<path_to_install_directory>/scripts/err.py

In many cases, just typing err.py will be enough as it is generally added to the PATH automatically. Please pass -h or --help to err.py to get a list of supported parameters. Depending on your situation, you may need to pass --config or --backend when starting Err.

If all that worked, you can now use the -d (or --daemon) parameter to run it in a detached mode:

<path_to_install_directory>/scripts/err.py --daemon

If you are going to run your bot all the time then using some process control system such as supervisor is highly recommended. Installing and configuring such a system is outside the scope of this document however.

Hacking on Err's code directly

It's important to know that as of version 2.0, Err is written for Python 3. In order to run under Python 2.7 the code is run through 3to2 at install time. This means that while it is possible to run Err under Python 3.3+ directly from a source checkout, it is not possible to do so with Python 2.7. If you wish to develop or test with Err's code under 2.7, you must run:

python setup.py install

Alternatively, you can also look into the --editable parameter of pip install.

After starting Err, you should add the bot to your buddy list if you haven't already. You can now send commands directly to the bot, or issue commands in a chatroom that the bot has also joined.

To get a list of all available commands, you can issue:

!help full

If you just wish to know more about a specific command you can issue:

!help command

Managing plugins

To get a list of public plugin repos you can issue:

!repos

To install a plugin from this list, issue:

!repos install <name of plugin>

You can always uninstall a plugin again with:

!repos uninstall <plugin>

You will probably want to update your plugins periodically. This can be done with:

!repos update all

Note: Please pay attention when you install a plugin, it may have additional dependencies. If the plugin contains a requirements.txt then Err wil automatically check them and warn you when you are missing dependencies.

Writing your own plugins is extremely simple. As an example, this is all it takes to create a "Hello, world!" plugin for Err:

from errbot import BotPlugin, botcmd

class Hello(BotPlugin):
    """Example 'Hello, world!' plugin for Err"""

    @botcmd
    def hello(self, msg, args):
        """Return the phrase "Hello, world!" to you"""
        return "Hello, world!"

This plugin will create the command "!hello" which, when issued, returns "Hello, world!" to you. For more info on everything you can do with plugins, see the documentation at https://github.com/gbin/err/wiki/plugin-dev