ac480f6c85 | ||
---|---|---|
Propellor | ||
Utility | ||
debian | ||
privdata | ||
.gitignore | ||
CHANGELOG | ||
GPL | ||
Makefile | ||
Propellor.hs | ||
README.md | ||
Setup.hs | ||
TODO | ||
config-joeyh.hs | ||
config-simple.hs | ||
config.hs | ||
propellor.cabal | ||
propellor.hs |
README.md
This is a configuration management system using Haskell and Git.
Propellor enures that the system it's run against satisfies a list of properties, taking action as necessary when a property is not yet met.
Propellor is configured via a git repository, which typically lives in ~/.propellor/. The git repository contains a config.hs file, and also the entire source code to propellor.
You typically want to have the repository checked out on a laptop, in order to make changes and push them out to hosts. Each host will also have a clone of the repository, and in that clone "make" can be used to build and run propellor. This can be done by a cron job (which propellor can set up), or a remote host can be triggered to update by running propellor on your laptop: propellor --spin $host
Properties are defined using Haskell. Edit config.hs to get started. For API documentation, see http://hackage.haskell.org/package/propellor/
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.
Also avoided is any form of node classification. Ie, which hosts are part of which classes and share which configuration. It might be nice to use reclass[1], but then again a host is configured using simply haskell code, and so it's easy to factor out things like classes of hosts as desired.
quick start
-
Get propellor installed
cabal install propellor
orapt-get install propellor
-
Run propellor for the first time. It will set up a
~/.propellor/
git repository for you. -
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. -
If you don't have a gpg private key, generate one:
gpg --gen-key
-
Run:
propellor --add-key $KEYID
-
Edit
~/.propellor/config.hs
, and add a host you want to manage. You can start by not adding any properties, or only a few. -
Pick a host and run:
propellor --spin $HOST
-
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. :) -
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
andgit push
changes that affect any number of hosts. -
Write some neat new properties and send patches to propellor@joeyh.name!
security
Propellor's security model is that the hosts it's used to deploy are untrusted, and that the central git repository server is untrusted too.
The only trusted machine is the laptop where you run propellor --spin
to connect to a remote host. And that one only because you have a ssh key
or login password to the host.
Since the hosts propellor deploys are not trusted by the central git repository, they have to use git:// or http:// to pull from the central git repository, rather than ssh://.
So, to avoid a MITM attack, propellor checks that any commit it fetches from origin is gpg signed by a trusted gpg key, and refuses to deploy it otherwise.
That is only done when privdata/keyring.gpg exists. To set it up:
gpg --gen-key # only if you don't already have a gpg key
propellor --add-key $MYKEYID
In order to be secure from the beginning, when propellor --spin
is used
to bootstrap propellor on a new host, it transfers the local git repositry
to the remote host over ssh. After that, the remote host knows the
gpg key, and will use it to verify git fetches.
Since the propoellor git repository is public, you can't store in cleartext private data such as passwords, ssh private keys, etc.
Instead, propellor --spin $host
looks for a
~/.propellor/privdata/$host.gpg
file and if found decrypts it and sends
it to the remote host using ssh. This lets a remote host know its own
private data, without seeing all the rest.
To securely store private data, use: propellor --set $host $field
The field name will be something like 'Password "root"'; see PrivData.hs
for available fields.
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.