[Goladus]

About testing puppet changes...

If I had to do it again I would probably ditch the puppetmaster altogether and use an rsync server to distribute the entire configure repository to every server, then run puppet locally to apply changes. This way you can simply modify any local repository and run puppet to apply the desired configuration to any machine you want. When you're happy with the changes you can check them in.

Using the puppetmaster and the puppet fileserver was trickier, essentially I would use FACTER_var="value" to pass in a value to puppet that would use local files rather than central files (which came pretty close to the purely decentralized model anyway).