add-dependabot-branch-entries

add-dependabot-branch-entries

Duplicates the entries in a repository's Dependabot config that target one branch, retargeting the copies at a newly created branch, so Dependabot starts raising PRs against the new release line.

This is the inverse of what retire-branch.yml does when a line is retired, and it edits the config in the same place: the repository's default branch. Dependabot reads .github/dependabot.yml only from there — a copy on any other branch is inert, which is what separates this action from copy-dependabot-config.

Behaviour

1. Clones the default branch and finds .github/dependabot.yml or .github/dependabot.yaml. With neither present it warns and exits 0.
2. If any entry already targets the new branch, it stops — this is what makes a re-run safe.
3. Copies every entry that targets the source branch, with target-branch set to the new branch. The originals are left exactly as they were.
   • When the source branch is the default branch, entries with no target-branch are part of the set: an absent target-branch implicitly means the default branch. Their copies get an explicit one.
   • The copies are produced by merging {"target-branch": <new>} rather than assigning: inside yq's += argument an assignment to a key the entry does not already have is silently dropped, which would leave those copies duplicating the originals verbatim.
4. Stages, captures the patch, then commits and pushes to the default branch.

What it does not do

A copied entry keeps the original's milestone. After a train rollover main's milestone number belongs to the new branch's line, so the copy is right and main's own entry is left pointing at the old milestone. Repointing it is a manual follow-up.

Inputs

Name	Required	Default	Description
repository	yes		Repository whose config is updated (org/repo-name)
new-branch	yes		Branch the duplicated entries should target (e.g. 5.0.x)
source-branch	no	the default branch	Branch whose entries are duplicated
commit-message	no	Add Dependabot entries for <new-branch>	Commit message
git-user-name	no	Spring Builds	Git author name
git-user-email	no	svc.spring-builds@broadcom.com	Git author email
dry-run	no	false	Stage and capture the patch, commit and push nothing
token	yes		Token with contents: write on the repository

Outputs

Name	Description
changed	true when entries were added
patch-file	Path to the captured diff, empty when nothing changed

Example

- uses: spring-cloud/spring-cloud-github-actions/.github/actions/add-dependabot-branch-entries@main
  with:
    repository: spring-cloud/spring-cloud-config
    new-branch: 5.0.x
    token:      ${{ secrets.GH_ACTIONS_REPO_TOKEN }}

Used by setup-next-release-train.yml.