I have just started creating a new sample Bcfg2 repository on github. This post details the strategy used in this repository in order to make it easy to pull in updates and merge them seamlessly with your running Bcfg2 instance.
The primary goal for this repository is to be nondestructive when someone tries to pull in the changes from upstream. However, in order to do this, there is a slightly more complicated repository structure involved.
The first thing you’ll probably want to do is grab a copy of the repository:
git clone git://github.com/solj/bcfg2-repo.git
As you inspect the repository, you’ll notice that I have tried to make use of Xinclude in order to prevent overwriting custom repository files. The idea is that you will have 3 separate files (file.xml, upstreamfile.xml, and localfile.xml). The basic format for file.xml will be a comment with information about the purpose of the file. Then it will xinclude localfile.xml and have a comment containing the xinclude for upstreamfile.xml. The reasoning behind this is that you will most often have slight changes in your local repository from what is contained upstream. Therefore, you will most likely populate localfile.xml and merge in any changes from upstreamfile.xml manually.
This appears to be working out well so far (although I haven’t really added enough content yet). I am also considering adding paths to default configuration files (e.g. ssh). I am thinking about populating them using group-specific files so that they can be overridden by adding a group file with a higher priority. I am also considering possibly adding a separate layout under Cfg/TCheetah/TGenshi and using altsrc to bind the entries from the Bundles.
I’m hoping this all works out and any comments/criticisms are welcome. I know that the useful examples out there are sparse and widespread. I’m hoping that we can get something together which allows people to collaborate on useful configurations easily so that the initial barrier to using Bcfg2 is decreased.