I’m looking for a tool or set of tools to manage configuration both for our scala application stack and other applications, e.g. lighttpd.
I’ve been thinking of using Apache Zookeeper, but I haven’t found anything that looks like a module for lighttpd (and possibly others). I also considered using for example Puppet, but there doesn’t seem to be much of a Zookeeper module for it.
Essentially what I’m trying to achieve is to have one service that keeps configuration & that I can reconfigure dynamically and that would propagate to all services, both on and off the JVM.
Honestly, pick one of the Open Source Configuration Management Systems. One interesting choice that have recently appear and is not listed on Wiki is ANSIBLE.
Also, your problem might be one of orchestration, in which case tools like Chef’s Knife, Capistrano, Fabric or MCollective are more adequate.
It might even be you want both, of course.
The best choice would be one written in a language you are familiar with. I don’t know of any written in Scala, though this blog post is interesting. For programmers, Chef has great attraction, and handles very dynamic configurations well. I know someone who uses it to create/destroy VM instances on-demand, depending on the application load — try that with Puppet, and you’ll cry.
I like Puppet’s declarative configuration style, and in particular the fact that it insulates you a lot from the Operating System differences. To Puppet, a Package is a Package, no matter what operating system you are using.
As for “Zookeeper module”… you might find good recipes/modules for these tools online, but you better be prepared to write your own. Do not chose based on the existence of one particular module — chose based on how comfortable you feel writing them.