Using git, how do I ignore a file in one branch but have it committed in another branch?

I've got a project that I'm deploying to Heroku. The source code tree includes a bunch of mp3 files (the website will be for a recording project I was heavily involved with).

I'd like to put the source code for it up on GitHub, but GitHub has a 300 MB limit on their free accounts. I don't want to use 50 MB of my limit on a bunch of mp3 files. Obviously, I could add them to the .gitignore file to keep them out of my repo.

However, I deploy to Heroku using git push heroku. The mp3 files must be present in the branch I push to Heroku so that they get get deployed.

Ideally, I'd like to .gitignore the mp3 files in my local master branch so that when I push that to GitHub, the mp3s are not included. Then I'd keep a local production branch that has the mp3s committed rather than ignored. To deploy, I would merge master into production, and then push the production branch to Heroku.

I can't get this to work right.

Here's an example of what I'm trying to do...

$ git init git-ignore-test
$ cd git-ignore-test
$ echo "*.ignored" >> .gitignore
$ git add .gitignore && git commit -m "Ignore .ignored files"
$ touch Foo.ignored

At this point, Foo.ignored is ignored in my master branch, but it's still present, so my project can use it.

$ git checkout -b unignored
$ cat /dev/null > .gitignore
$ git add Foo.ignored .gitignore && git commit -m "Unignore .ignored files"

Now I've got a branch with these files committed, as I want. However, when I switch back to my master branch, Foo.ignored is gone.

Anyone got any suggestions for a better way to set this up?

Edit: just to clarify, I want the mp3 files to be present in both branches so that when I run the site locally (using either branch) the site works. I just want the files ignored in one branch so when I push to GitHub they are not pushed as well. Usually .gitignore works well for this kind of thing (i.e. keeping a local copy of a file that does not get included in a push to a remote), but when I switch to the branch with the files checked in, and then back to the branch with the files ignored, the files vanish.

This solution appears to work only for certain, patched versions of git. See a new answer pointing to workarounds and another answer and subsequent comments for a hint which versions may work.

I wrote a blog post on how to effectively use the excludesfile for different branches, like one for public github and one for heroku deployment.

Here's the quick and dirty:

$ git branch public_viewing
$ cd .git/
$ touch info/exclude_from_public_viewing
$ echo "path/to/secret/file" > info/exclude_from_public_viewing 

then in the .git/config file add these lines:

[core]
excludesfile = +info/exclude


[branch "public_viewing"]
excludesfile = +info/exclude_from_public_viewing

Now all the global ignore stuff is in the info/exclude file and the branch specific is in the info/exclude_from_public_viewing

Hope that helps!

http://cogniton-mind.tumblr.com/post/1423976659/howto-gitignore-for-different-branches

Important hint: The accepted answer by Cognition.Mind doesn't work (anymore, for several years now, or perhaps for vanilla versions of git); see the comments. A valid answer and workaround can be found here:

https://stackoverflow.com/a/29583813/2157640

Another alternative workaround (working for my particular problem, but demanding manual stash operations or implementation of a hook) would be git stash -u -a. This is tedious when the differences are large.

And finally, the solution I'm now going with is having forked my VM that we hold our development environment in, and set up info/excludes appropriately for the branch, respectively deleting the offending, uncommitted files/folders.

Let's say we want to ignore build folder from all other branch except production branch . As we want to push build folder in production.

1) Dont include build in .gitignore . If you do that it will always be ignored for all branches .

2) Create a file exclude_from_public_viewing inside ./.git/info (This folder already exists) folder touch ./.git/info/exclude_from_public_viewing

3) Inside exclude_from_public_viewing write one line (As you are trying to ignore build for all the branches). !build

4)There's an existing file .git/info/exclude . We need to add following line in it.

 build

We want to ignore build folder but hasn't added it in .gitignore . So how git will know what to ignore ? Answer is we are adding it to exclude file and conditionally passing that file to git config

5) Now we have to conditionally unignore build folder for production branch. to do that perform following

6) There is a existing file called ./.git/config we need to add following -

a) excludesfile = +info/exclude below [core]

[core]
     excludesfile = +info/exclude

b) Create a new section in the end of ./.git/config as

[branch "production"]
    excludesfile = +info/exclude_from_public_viewing

Solution 2

There is one smart alternate solution . Lets say you want to add build/ folder in production branch and ignore it in all other branches.

1) Add it to your gitignore file.

2) In production branch, while doing git add, force add build folder: git add -f --all build/

I would strongly advise considering putting those MP3 files on S3. Having them be part of your Heroku push (and thus part of your Heroku slug) will greatly slow down your dyno startup time. Since Heroku uses EC2, if the files are on S3 and are only accessed by your app (if users aren't directly linked to S3) you won't even pay any bandwidth charges, only the charge to store 50MB.

Have you tried having .gitignore be different in your branch?

You should be able to ignore what you want based on the branch you are in as long as the files are not tracked on that branch.