It was interesting to see Clint Adams describe love and dissatification with configuration management.
At work I've got control of 150(ish) machines which are managed via CFEngine. These machines are exclusively running Debian Lenny. In addition to these hosts we also have several machines running Solaris, OpenBSD, and various Ubuntu releases for different purposes.
Unfortunately I made a mistake when I setup the CFEngine infrastructure and when writing all the policies, files, etc, I essentially said "OK CFEngine controlled? Then it is Debian". (This has been slowly changing over time, but not very quickly.)
But in short this means that the machines running *BSD, Solaris, and non-Debian distributions haven't been managed as well via CFEngine as the rest, even though technically they could have been.
A while back I decided that it was time to deal with this situation. Looking around the various options it seemed Puppet was the way of the future and using that we could rewrite/port our policies and make sure they were both cleanly organised and made no assumptions.
So I setup a puppetmaster machine, then I installed the client on a range of client machines (openbsd, debian lenny, ubuntu, solaris) so that I could convince myself my approach was valid, and that the tool itself could do everything I wanted it to do.
Unfortunately using puppet soon became painful. It has primitives for doing various things such as maintaining local users, working with cronjobs, and similar. Unfortunately not all primitives work upon all platforms, which kinda makes me think "what's the point?". For example the puppet client running upon FreeBSD will let you add a local user, setup a ~/.ssh/authorized_keys file but will not let you setup a password. (Which means you can add users who can login, but then cannot use sudo. Subpar)
At this point I've taken a step back. As I think I've mentioned before I don't actually do too much with CFEngine. Just a few jobs:
- Fetch a file from the master machine and copy into the local filesystem. (Making no changes.)
- Fetch a file from the master machine, move it to the local system after applying a simple edit. (e.g "s/##HOSTNAME##/`hostname`/g")
- Install a package.
- Purge a package.
- Setup local user accounts, with ~/.ssh handled properly.
- Apply one-line sed-style edits to files. (e.g. "s/ENABLED=no/ENABLED=yes/" /etc/default/foo)
(i.e. I don't use cron facilities, I add files to cron directories. Similarly I don't use process monitoring, instead I install the monit package and drop /etc/monit/monitrc into place.)
There is a pretty big decision to make in the future with the alternatives being:
- Look at Chef.
- Stick with CFEngine but start again with a better layout, with more care and attention to portability things.
- Replace the whole mess with in-house-fu.
If we ignore the handling of local users, and sudo setup, then the tasks that remain are almost trivial. Creating a simple parser for a "toy-language" which can let you define copies, edits, and package operations would be an afternoons work. Then add some openssl key authentication and you've got a cfengine-lite.
For the moment I'm punting the decision but I'm 90% certain that the choice is CFEngine vs. Chef vs. In-House-Fu - and that puppet is no longer under consideration.
Anyway despite having taken months to arrive at this point I'm going to continue to punt. Instead my plan is to move toward using LDAP for all user management, login stuff, and sudo management. That will be useful in its own right, and it will coincidentally mean that whatever management system we do end up using will have on less task to deal with. (Which can only be a good thing.)
ObFilm: Terminator II
