Default branch migration

[mrueg]

Default Branch Migration

This document outlines steps needed to migrate the default branch
of your repo from master to main.

Note: This document is currently a work in progress.

If you have questions about the process, reach out to the GitHub Management Team
on the #github-management channel on slack or open an issue in the kubernetes/org repo.

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
  (see kubernetes/test-infra#20665 for an example).

• If the milestone_applier prow config references the master branch,
  add the main branch to the config (see kubernetes/test-infra#20675 for an example).

• If the branch_protection prow config references the master branch,
  add the main branch to the config.

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).

  • For bootstrap-based jobs, ensure the branch is explicitly specified,
    e.g. kubernetes/foo=main. kubernetes/test-infra#20667 may eventually
    allow for non-disruptive changes.
  • For pod-utils based jobs, ensure the branch is explicitly specified,
    e.g. base_ref: main. kubernetes/test-infra#20672 may eventually allow
    for non-disruptive changes.

• 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.

• 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

  • e.g. using git to auto-detect

  # for existing clones, update their view of the remote
  git fetch origin
  git remote set-head origin -a
  # for new clones, or those updated as above, this prints "main" post-rename
  echo $(git symbolic-ref refs/remotes/origin/HEAD)

  • e.g. using github's api to auto-detect

  # gh is https://github.com/cli/cli, this will print "main" post-rename
  gh api /repos/kubernetes-sigs/slack-infra | jq -r .default_branch

• If the repo has netlify configured for it, ask a member of the GitHub
  Management Team to rename the master branch to main in the netlify site config.
  It can't be controlled through the netlify config in the repo.

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 kubernetes/test-infra#20669 for an example).

Prow config

• If the milestone_applier prow config references the master branch,
  remove it from the config.

• If the branch_protection prow config references the master branch,
  remove it from the config.

Other

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

• 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

• 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.

Cross-ref: kubernetes/org#2222

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[k8s-triage-robot]

The Kubernetes project currently lacks enough contributors to adequately respond to all issues and PRs.

This bot triages issues and PRs according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Mark this issue or PR as fresh with /remove-lifecycle stale
• Mark this issue or PR as rotten with /lifecycle rotten
• Close this issue or PR with /close
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/lifecycle stale

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/remove-lifecycle stale

[k8s-triage-robot]

The Kubernetes project currently lacks enough contributors to adequately respond to all issues and PRs.

This bot triages issues and PRs according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Mark this issue or PR as fresh with /remove-lifecycle stale
• Mark this issue or PR as rotten with /lifecycle rotten
• Close this issue or PR with /close
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/lifecycle stale

[mrueg]

/remove-lifecycle stale

[k8s-triage-robot]

The Kubernetes project currently lacks enough contributors to adequately respond to all issues and PRs.

This bot triages issues and PRs according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Mark this issue or PR as fresh with /remove-lifecycle stale
• Mark this issue or PR as rotten with /lifecycle rotten
• Close this issue or PR with /close
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/lifecycle stale

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/lifecycle frozen

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This is scheduled for Friday 9th Dec.