Merging

Pull Requests

You have some commits in a branch, and you’re ready to merge. The Pulp Team makes use of pull requests for all contributions. Please have a look at our Contribution checklist.

On the GitHub page for the repo where your development branch lives, there will be a “Pull Request” button. Click it. From there you will choose the source and destination branches.

If there is a bug for this issue, please title the pull request “<bug_id> - Short Message”. In the comment section below, please include a link to the issue. Use of GitHub’s markdown for the link is prefered. Example: [Issue 123456](https://link.tobug) Additionally, please also include a link to the pull request in the bugs notes.

If there is a Redmine issue associated with the commit, please add closes #<issue number> somewhere in the commit. This will set the issue to MODIFIED upon merging. Additionally, you can add re #<issue number> <some message> which will add a comment to the issue upon merging.

For details about using pull requests, see GitHub’s official documentation.

Review

Once a pull request has been submitted, a member of the team will review it. That person can indicate their intent to review a particular pull request by assigning it to themself.

Comments on a pull request are meant to be helpful for the patch author. They may point out critical flaws, suggest more efficient approaches, express admiration for your work, ask questions, make jokes, etc. Once review is done, the reviewer assigns the pull request back to the author. The next step for the author will go in one of two directions:

  1. If you have commit access and can merge the pull request yourself, you can take the comments for whatever you think they are worth. Use your own judgement, make any revisions you see fit, and merge when you are satisfied. Think of the review like having someone proof-read your paper in college.
  2. If you are a community member and do not have commit access, we ask that you take the review more literally. Since the Pulp Team is accepting responsibility for maintaining your code into perpetuity, please address all concerns expressed by the reviewer, and assign it back to them when you are done. The reviewer will strive to make it clear which issues are blocking your pull request from being merged.

Note

To the community: The Pulp Team is very grateful for your contribution and values your involvement tremendously! There are few things in an OSS project as satisfying as receiving a pull request from the community.

We are very open and honest when we review each other’s work. We will do our best to review your contribution with respect and professionalism. In return, we hope you will accept our review process as an opportunity for everyone to learn something, and to make Pulp the best product it can be. If you are uncertain about comments or instructions, please let us know!

Rebasing and Squashing

Before you submit a pull request, consider an interactive rebase with some squashing. We prefer each PR to contain a single commit. This offers some significant advantages:

  • Squashing makes it more likely that your merge will be fast-forward only, which helps avoid conflicts.
  • Nobody wants to see your typo fixes in the commit log. Consider squashing trivial commits so that each commit you merge is as story-focused as possible.
  • The git commit --amend command is very useful, but be sure that you understand what it does before you use it! GitHub will update the PR and keep the comments when you force push an amended commit.
  • Rebasing makes cherry picking features and bug fixes much simpler.

If this is not something that you are comfortable with, an excellent resource can be found here:

How to Rebase a Pull Request

Warning

Keep in mind that rebasing creates new commits that are unique from your original commits. Thus, if you have three commits and rebase them, you must make sure that all copies of those original commits get deleted. Did you push your branch to origin? Delete it and re-push after the rebase.

Merging Checklist

Before you merge your Pull Request on Github, here is a list of things to consider. Note that not all may be applicable to your change. For example, a pulp-smash test plan is not needed for changes that only refactor code.

  • Post the Github pull request URL as a comment on the plan.io issue and transition the state of the issue to POST
  • Add and associate a pulp-smash test plan to your plan.io issue if needed
  • If your change is a new feature, add a release note
  • If your change is a new feature, add documentation for the feature

Merging your Changes

After a PR is marked as approved by all reviewers, you can then merge your changes. First, hit the “Merge pull request” button on your PR on the Github website.

You will now need to merge your changes forward. Here are the rules for merging forward:

  • If your commit is on X.Y-dev, you want to merge X.Y-dev to the next higher version’s dev branch. This will typically be X.Y+1-dev.
  • When you are done merging through the various dev branches, merge the highest dev branch to 2-master.

For example, if you merge a PR to 2.7-dev and the only newer dev branch is 2.8-dev, you would merge 2.7-dev into 2.8-dev, then 2.8-dev into 2-master.

You will also want to set the “Target Release” field in the redmine issue. “Target Release” is available for Issues, Refactors, and Stories but not for Tasks. If you have a task that appears to need a target release, please consider using one of the other three issue types.

For cases where there are substantial merge conflicts whose resolution merits review, create a new branch from your working branch and merge the dev branch into it. For example, assume you have branch hot-new-feature based on the 2.7-dev branch, and substantial conflicts merging to 2.8-dev.

$ git checkout hot-new-feature
$ git checkout -b hot-new-feature-2.8
$ git merge 2.8-dev

At this point you can resolve conflicts, then create a pull request from hot-new-feature-2.8 into 2.8-dev.

Merging to Old Releases Only

Infrequently, there may be a need to apply a change to an old release but not newer releases. This should only be a last resort.

One way or another, it is important to merge this change into newer release branches, even if the actual changes don’t get applied. When fixing code that no longer exists in newer branches, simply do the merge and resolve any conflicts that arise.

Otherwise, to merge the work but not apply any of its code changes, use merge strategy “ours”.

$ git merge -s ours my-important-fix

In either case, git’s history records that your fix has been applied to each branch. Make sure the human-readable description of your fix accurately describes its scope. For more on how to write a good commit message, see the Commit Messages section of our branching page.