Configuration Management Software for Linux for "harvesting" config-files

Managing 50 servers manually, and been looking through the different cms for linux (cfengine,puppet,chef etc) It's use will primarily for CM for config-files.

Is there a cms out there that gather information from the existing servers? So i don't have to write class'es, recipies etc for each server, but automatically gets config-files from my server, so I can edit them centrally later?

Blueprint can generate Puppet or Chef configurations from your existing servers, if you want to start using one of those two tools.

Alternatively, etckeeper will help you keep the whole of /etc in a VCS, if that's all you need (with a little bit of config, you could then keep the repositories somewhere central).

Blueprint author here and it does exactly what you need. We like to say it reverse engineers a server - that is detects packages, source files and configurations tweaks, then packages it up in a reusable format. Check it out on github: https://github.com/devstructure/blueprint.