angry_mob

This is AngryMob

AngryMob (AM) is the automated system configuration component of YesMaster.

It combines:

• convenient configuration data (the node)
• idempotent code to ensure the configuration of the parts of a system (targets)
• and a method of controlling the flow of the setup (acts)

AngryMob values having:

• zero external dependencies.
• a small, simple core.
• Rubiness.

Having zero external dependencies means that AM can be used from the very moment a bare ruby interpreter is installed on a server.

A small, simple core means that debugging and testing the code is simplified. It also allows AM to be embedded directly into other projects.

Please note that AngryMob is a reaction to Chef. Despite this, I retain the utmost respect the Chef movement and the guys who've built it.

AM purposely omits or eschews the following features you might be familiar with from Chef:

• The client and server and its dependencies. AM operates similarly to "chef-solo" or is combined with other components for network based "chef-client"-like operation.
• A built in, fixed cookbook layout and metadata. You can define your own ResourceLocator, or use the basic supplied one.
• A single copy nirvana implementation. Again, define it yourself if you want it.
• The puppet resource/provider separation. I don't have a particular solution to supporting multiple operating systems, but its strongly YAGNI for now.
• Exhaustive system discovery like Ohai. I think Ohai is great, but running it before every AM run to find the hostname and IP is excessive.
• Type-checking of data. This is ruby, where ducks rule the roost.

Status

AngryMob is young and fluid, but I'm using it a lot in the maintainence of VPSes at PLUS2.

In particular, AM lacks any unit-level specs or tests so far. The servers it maintains are valid functional testing in my eyes ;)

Taxonomy

• The node is a glob of data representing the thing you're configuring.
• targets are things you want to configure.
• acts are groups of target invocations. They can also schedule the execution of other acts.
• mobs are groups of acts and targets.

The Node

The Node is a place to hang your data. In essence its a Hash (though more specifically its an AngryHash, which is similar to Hashie::Mash)

Targets

Targets are parts of the server which you want to configure, for example:

• directories
• templates
• users

Note the targets interface is likely to change soon. Its overly complicated right now.

Targets perform a similar role to Chef/puppet resource/providers.

TODO talk about Target definition dsl and SingletonTargets

Acts

Acts are groups of targets. They're conceptually similar to a rake task. Subsequent acts can be scheduled.

Mobs

Mobs are groups of target definitions and acts. They can be mixed and matched.

common mob

http://github.com/plus2/common_mob

A small toolkit of handy targets:

• dir
• file
• template - ERB
• symlink
• tarball
• fetch
• git
• user
• apt - apt-get package
• gem - a rubygem
• block - a ruby block
• sh - a shell command
• service - a super-class for defining ubuntu service targets

The mob command

"chef-solo"-like command for setting an AngryMob on your server.

TODO write!

Meta

AngryMob was written by Lachie Cox for PLUS2 and YesMaster.

It lives at http://github.com/plus2/angry_mob.

Please try it out and send us feedback via the github page.

License

Copyright (c) 2010 PLUS2

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.