Merging from Upstream Buildpacks
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This topic describes how to maintain your forked buildpack by merging it with the upstream buildpack. This allows you to keep your fork updated with changes from the original buildpack, providing patches, updates, and new features.
The following procedure assumes that you are maintaining a custom buildpack that was forked from a Cloud Foundry system buildpack. However, you can use the same procedure to update a buildpack forked from any upstream buildpack.
To sync your forked buildpack with an upstream Cloud Foundry buildpack:
Navigate to your forked repo on GitHub and click Compare in the upper right to display the Comparing changes page. This page shows the unmerged commits between your forked buildpack and the upstream buildpack.
Inspect the unmerged commits and confirm that you want to merge them all.
In a terminal window, navigate to the forked repo and set the upstream remote as the Cloud Foundry buildpack repo.
$ cd ~/workspace/ruby-buildpack $ git remote add upstream email@example.com:cloudfoundry/ruby-buildpack.git
Pull down the remote upstream changes.
$ git fetch upstream
Merge the upstream changes into the intended branch. You may need to resolve merge conflicts. This example shows merging the
masterbranch of the upstream buildpack into the
masterbranch of the forked buildpack.
$ git checkout master $ git merge upstream/master
Note: When merging upstream buildpacks, do not use
git rebase. This approach is not sustainable because you confront the same merge conflicts repeatedly.
Run the buildpack test suite to ensure that the upstream changes do not break anything.
$ BUNDLE_GEMFILE=cf.Gemfile buildpack-build
Push the updated branch.
$ git push
Your forked buildpack is now synced with the upstream Cloud Foundry buildpack.
For more information about syncing forks, see the Github topic Syncing a Fork.