Change default branch to "main"

[vincepri]

Once the community agrees on the naming, we need to change our default development branch to main, and check that any tools or references to it are changed as well.

This includes the container image tag used in development.

/kind cleanup
/wg naming
/milestone Next

[fejta-bot]

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Mark the issue as fresh with /remove-lifecycle stale.
Stale issues rot after an additional 30d of inactivity and eventually close.

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Send feedback to sig-testing, kubernetes/test-infra and/or fejta.
/lifecycle stale

[vincepri]

/lifecycle frozen

[sbueringer]

I unfortunately don't really have time to do it myself, but is this something that we might want to tackle soon @vincepri?

[sbueringer]

https://www.kubernetes.dev/resources/rename/

Steps:

Prerequisites

• Create an issue in your repo to track the branch rename.
  You can paste this checklist in the issue body.

• If you are not a root approver for the repo, assign a root
  approver for approval.

• Once the issue has been approved, send a notice to your SIG's
  mailing list about the potential branch rename.

Changes pre-rename

Make the following changes before renaming the branch the master branch.

Note: There might be additional changes required that have not been
covered in this checklist.

Anytime

These changes are non-disruptive and can be made anytime before renaming
the branch.

• If a presubmit or postsubmit prowjob triggers on the master branch
  (branches field of the prowjob), add the main branch to the list

  • PR: controller-runtime: change jobs to main kubernetes/test-infra#28742

• If the [milestone_applier] prow config references the master branch => milestone applier not used by CR

• If the [branch_protection] prow config references the master branch => not configured for CR

Just before rename

These changes are disruptive and should be made just before renaming the
branch.

• For periodic prowjobs, or any prowjob that mentions the master branch
  in base_ref, update them to the main branch. Ensure that these changes
  happen in lock-step with the branch rename (jobs triggered in between landing
  these changes and renaming the branch will fail).

  • PR: controller-runtime: change jobs to main kubernetes/test-infra#28742

• If a prowjob mentions master in its name, rename the job to not include
  the branch name, e.g. pull-repo-verify-master -> pull-repo-verify.
  [status-reconciler] should automatically migrate PR status contexts to the
  new job name, and retrigger accordingly, but we have anecdotally found it
  sometimes misses changes.

  • NOTE: our infrastructure doesn't understand the concept of job renames, so
    from the perspective of e.g. https://testgrid.k8s.io the job will appear to
    have lost history and start from scratch.
  • PR: controller-runtime: change jobs to main kubernetes/test-infra#28742

• If a prowjob calls scripts or code in your repo that explicitly
  reference master, update all references to use main, or auto-detect the
  remote branch => does not apply

• If the repo has netlify configured for it, ask a member of the GitHub => Netlify is not used

Approval

• Once all non-disruptive tasks have been completed and disruptive tasks
  have been identified, assign the GitHub Management team (@kubernetes/owners)
  for approval.

Rename the default branch

• Rename the default branch from master to main using the GitHub UI
  by following the official instructions.

Changes post-rename

After the default branch has been renamed to main, make the following
changes.

Note: There might be additional changes required that have not been
covered in this checklist.

Prowjobs

• If a prowjob still references the master branch in the branches field,
  remove the master branch (see [Update kubernetes/org job configs post default-branch-rename kubernetes/test-infra#20669] for an example).
  • PR: controller-runtime: remove master after branch rename kubernetes/test-infra#28775

Prow config

• If the [milestone_applier] prow config references the master branch,
  remove it from the config. => does not apply

• If the [branch_protection] prow config references the master branch,
  remove it from the config. => does not apply

Other

• If any docs reference the master branch, update to main
  (URLs will be automatically redirected).

  • PR: 📖 Replace occurences of master with main #2203

• Ensure that CI and PR tests work fine.

  • If there are any outstanding PRs you can /approve to merge, do so to verify
    that presubmits and postsubmits work as expected
  • PR: 📖 Replace occurences of master with main #2203

• Trial the local development experience with a pre-rename clone.

  • ensure Github instructions to rename your local branch work
  • consider updating your fork's default remote branch name such that if you
    have git autocompletion enabled, typing ma<tab> will autocomplete to main

• Send a notice about the branch rename to your SIG's mailing list.
  Include the link to the GitHub instructions to rename your local branch.

  • e.g. https://groups.google.com/g/kubernetes-sig-cluster-lifecycle/c/b8B-VKk2LUQ/m/v5_6soszAAAJ

[sbueringer]

/assign

[sbueringer]

Once the issue has been approved, send a notice to your SIG's mailing list about the potential branch rename.

@vincepri @joelanford @alvaroaleman @FillZpp Any objections?

Also WDYT should we send a mail out before the rename or just afterwards (something like this https://groups.google.com/g/kubernetes-sig-cluster-lifecycle/c/b8B-VKk2LUQ/m/v5_6soszAAAJ)

[vincepri]

Sounds good! Thank you for taking care of this

[FillZpp]

+1 for my part. Looks like we should we send a mail first according to the prerequisites?

[sbueringer]

+1 for my part. Looks like we should we send a mail first according to the prerequisites?

Not sure, that's why I was asking 🙂

[joelanford]

+1 from me as well. I'd suggest message to the mailing list before and after, I think.

[sbueringer]

Mail is out: https://groups.google.com/g/kubernetes-sig-api-machinery/c/KfSVRcA_JC4

[sbueringer]

PR with all the necessary changes before we can actually rename the branch in the repo: kubernetes/test-infra#28742

[sbueringer]

Once all non-disruptive tasks have been completed and disruptive tasks
have been identified, assign the GitHub Management team (@kubernetes/owners)
for approval.

@nikhita Would be great if you can take a look. Thank you :)

Right now we're waiting to see if there are any objections on the mail: https://groups.google.com/g/kubernetes-sig-api-machinery/c/KfSVRcA_JC4 (which seems very very unlikely)

Then we merge this PR: kubernetes/test-infra#28742

And would go ahead with actually renaming the branch in the repo early next week.

[nikhita]

Once all non-disruptive tasks have been completed and disruptive tasks
have been identified, assign the GitHub Management team (@kubernetes/owners)
for approval.

@nikhita Would be great if you can take a look. Thank you :)

Looks great! Let's when lazy consensus is achieved!

[vincepri]

For folks trying to update local environments:

git branch -m master main
git fetch origin
git branch -u origin/main main
git remote set-head origin -a

[sbueringer]

All done

Let us know if any issues occur, but looks all good from my side.

/close

[k8s-ci-robot]

@sbueringer: Closing this issue.

In response to this:

All done

Let us know if any issues occur, but looks all good from my side.

/close

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