Mattermost tick-tock Branching Strategy

Mattermost uses a tick-tock release strategy where every other release is a “quality release” that only has bug fixes and no new features.

The following diagram provides an overview of the branching strategy used to accomplish this. As an example, release-5.4 is a feature release and release-5.5 is a quality release. Note the “quality release” branch is based on the previous release branch.

Cherry Pick Process - Developer 

When your PR is required on a release branch, you will follow the cherry picking process.

1. Make a PR to ‘master’ like normal.
2. Add the appropriate milestone and the CherryPick/Approved label.
3. When your PR is approved, it will be assigned back to you to perform the merge and any cherry picking if necessary.
4. Merge the PR.
5. An automated cherry-pick process will try to cherry-pick the PR. If the automatic process succeeds, a new PR pointing to the correct release branch will open with all the appropriate labels.
6. If the automated cherry-pick fails, the developer will need to cherry-pick the PR manually. Cherry-pick the master commit back to the appropriate releases. If the release branches have not been cut yet, leave the labels as-is and cherry-pick once the branch has been cut. The release manager will remind you to finish your cherry-pick.
7. Set the CherryPick/Done label when completed.

• If the cherry-pick fails, the developer needs to apply the cherry-pick manually.
• Cherry-pick the commit from master to the affected releases. See the steps below:
• Run the checks for lint and tests.
• Push your changes directly to the remote branch if the check style and tests passed.
• No new pull request is required unless there are substantial merge conflicts.
• Remove the CherryPick/Approved label and apply the CherryPick/Done label.

Note: - If the PR need to go to other release branches, you can run the command /cherry-pick release-x.yz in the PR comments and it will try to cherry-pick it to the branch you specified.

Cherry Pick Process - Reviewer 

If you are the second reviewer reviewing a PR that needs to be cherry-picked, do not merge the PR. If the submitter is a core team member, you should set the Reviews Complete label and assign it to the submitter to cherry pick. If the submitter is a community member who is not available to cherry pick their PR or can not do it themselves, you should follow the cherry pick process above.