You will need to have a script of some sort build the various branches of content for you. The basic way to do this is to add the content to the database (in your case, just by committing them to the master branch), then in a temporary index, reading in all the contents you want to have in each branch (git read-tree/git update-index), writing that tree out (git write-tree), writing a commit object (git commit-tree) and updating the branch to that new commit (git update-ref). These are all plumbing commands that are not normally used in day-to-day operations but allow you to build snapshots without having all the contents in a directory on disk at the same time.
An example script to do something like this is here:
http://github.com/schacon/gitcrazy/blob/master/update_content.rb
Here I define a number of servers that each have one or more roles ( memcache , database or webserver ). Then I can add content to a role like this:
$ update_content.rb /path/to/content file_name memcache
That will add the content to my git db, then update the branches for the servers that are affected (that have the memcache role, in this case). I can do that for multiple files for any of the roles and git will keep track of what content each server should have. Then each server can fetch their specific branch ( server/s1 , server/s2 , etc).
I m thinking of doing a quick screencast demonstrating this soon - hope the example script is helpful. It should be pretty easy to run and figure out what s going on. In the same project there is a list script that lists out what content is on which server branch.
