How to realise a deployment branch in Git

I'm using git for a PHP project, I think it's really handy. There is one thing that would be great if I get it to work.

I have created a branch, meant for deployment. It has some differences, like different configuration files and documentation.

I can't just ignore them, because then they will stay in both branches, while I would like to keep them different in both branches.

The problem is that when I merge the branches, those files that are meant to be different are merged too.

Is there any convenient way to accomplish such a thing? How is this normally done?

Solution

Update Feb. 2021: Git itself is still not a good fit, but GitHub Action environment could help.

2009: I am not sure Git is meant to be used this way.

First a quick Linus advice, always "colorful" and informative ;)

Git very fundamentally tracks project state, not file state. Which means that you very much can NOT try to "merge a file". It is a senseless operation in git, and in fact, any SCM that allows it pretty much is doomed to be a total piece of sh*t (*).

(*) And I'm not saying that just because git doesn't do it. It's much more fundamental than that. Once you start doing per-file branching and merging, you've basically screwed yourself, and you'll never be able to work on the project as a "whole project" any more - you no longer have a well-defined history that actually is the history of the whole project.

There.

That said, you could:

manage those config/doc files a separate git sub-projects (note: the use of submodules has been discussed here)
or record partial merge (using "ours" strategy for files we don't want to merge), then --amend it.

Other solutions in this thread involve working on a "server-specific" branch on your deployment server

Development        Deployment

#origin/master:
x--x               $ git clone

                   # master
                   x--x

                   $ git checkout -b deployment origin/master

                   x--x
                       \ 
                        -- #deployment

                   $ .... #makes changes for config files
                          #or other specific deployment files

                   x--x
                       \
                        --d1--d2 # no need to push that branch ever.

#new developments
x--x--x--x

                   $ git pull --rebase #pull origin/master and 
                                       #replay current branch on top of it
                   x--x--x--x
                             \
                              --d1'--d2' #SHA1 rewritten in deployment branch
                                         #not important since this branch 
                                         #is not pushed (published)