Application management

[Paul Dlug]

We have a stack of FreeBSD and solaris webservers behind load 
balancers. Most of our applications are pretty easy to deploy, 
requiring an apache install, some NFS mounts and some supporting 
software. I'd like to be able to run any application on any of our 
servers.

I'm trying to break up the parts of our cfengine configuration from the 
system specific to the application specific. I've been using the groups 
to define applications, such as "Webserver", adding a host to this 
group causes it to copy an additional apache configuration file and 
restart the server. It also adds necessary NFS mounts. This would 
enable us to increase and decrease the number of hosts  serving an 
application just by modifying a few group memberships.

(Sorry for the long background).

My issues are:
- Package management: what methods are people using to manage FreeBSD 
and/or Solaris packages with cfengine? I'd like to use platform 
specific packages were possible instead of something like RPM or OpenPKG
- "Undo": how do you gracefully handle the case were a server has been 
removed from a group and should no longer have the 
software/mounts/configuration needed for that app.
- Overlap: breaking up each application into a cfengine conf file 
leaves it self contained but creates overlaps (if different apps use 
the same NFS mount for example). What's the best way to define it once 
and list dependencies so that once the dependencies are gone the 
software decides it's no longer needed and removes it (thus solving the 
above problem).

Any suggestions would be greatly appreciated.

(If anyone would like to collaborate on using cfengine for application 
management and monitoring please let me know. I'm really interested in 
bringing forward some concrete solutions other people can implement).

--Paul