This Heroku buildpack adds support for Git submodules. This allows submodules to work with Github Sync. Heroku supports submodules natively, but only through Git pushes. This works around that limitation.

Others have attempted to provide this functionality by manually parsing the .gitmodules file. This is an unreliable methods. This is because the .gitmodules file only describes certain things about the submodules. The exact commit hash a submodule is bound to is actually stored in Git's object tree. Relying solely on .gitmodules to fetch submodules is therefor insufficient.

This buildpack takes a different approach and makes using the native Git way of resolving submodules work. It does this by actually fetching the Git objects. Normally this is lost during deployment, but this buildpack works around that. After that, it's a matter of executing git submodule update --init --recursive.

1. Add the buildpack to your Heroku app:

    heroku buildpacks:add https://github.com/thriver/heroku-buildpack-git-submodule
   

   Keep in mind that the buildpack order is important. If you'll specify this buildpack after your default one (e.g. heroku/nodejs) it'll not work. See https://devcenter.heroku.com/articles/using-multiple-buildpacks-for-an-app for details.

2. Set the GIT_REPO_URL to the SSH URL of your Git repo:

    heroku config:set GIT_REPO_URL=git@github.com:thriver/heroku-buildpack-git-submodule
   

3. Set GIT_SSH_KEY to the private SSH key that can access both your repo and its submodules:

    heroku config:set GIT_SSH_KEY=$(cat ~/.ssh/id_rsa)
   

4. Enjoy the ride :)

1. SSH Authentication only.

MIT License

Copyright (c) 2017 Sector Labs

Permission is hereby granted, free of charge, to any person obtaining a copy
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The above copyright notice and this permission notice shall be included in all
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