Propellor is a configuration management system using Haskell and Git. Each system has a list of properties, which Propellor ensures are satisfied.

Propellor is configured via a git repository, which typically lives in ~/.propellor/ on your development machine. Propellor clones the repository to each host it manages, in a secure way.

To trigger propellor to run on a host, run propellor --spin $host. Or run /usr/local/propellor/propellor on the host. Or use the runPropellor property to have Propellor set up a cron job.

Properties are defined using Haskell. Edit ~/.propellor/config.hs to get started. There is fairly complete API documentation.

There is no special language as used in puppet, chef, ansible, etc.. just the full power of Haskell. Hopefully that power can be put to good use in making declarative properties that are powerful, nicely idempotent, and easy to adapt to a system's special needs!

If using Haskell to configure Propellor seems intimidating, see configuration for the Haskell newbie.

quick start

1. Get propellor installed cabal install propellor or apt-get install propellor

2. Run propellor for the first time. It will set up a ~/.propellor/ git repository for you.

3. cd ~/.propellor/; use git to push the repository to a central server (github, or your own git server). Configure that central server as the origin remote of the repository.

4. If you don't have a gpg private key, generate one: gpg --gen-key

5. Run: propellor --add-key $KEYID

6. Edit ~/.propellor/config.hs, and add a host you want to manage. You can start by not adding any properties, or only a few.

7. Pick a host and run: propellor --spin $HOST

8. Now you have a simple propellor deployment, but it doesn't do much to the host yet, besides installing propellor.

   So, edit ~/.propellor/config.hs to configure the host (maybe start with a few simple properties), and re-run step 7. Repeat until happy and move on to the next host. :)

9. To move beyond manually running propellor --spin against hosts when you change their properties, add a property to your hosts like: Cron.runPropellor "30 * * * *"

   Now they'll automatically update every 30 minutes, and you can git commit -S and git push changes that affect any number of hosts.

10. Write some neat new properties and send patches to propellor@joeyh.name!

debugging

Set PROPELLOR_DEBUG=1 to make propellor print out all the commands it runs and any other debug messages that Properties choose to emit.