cherry-pick.yml

# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

name: Cherry Pick to Release Branch

on:
  issue_comment:
    types: [created]

permissions:
  contents: write
  issues: write
  pull-requests: write

jobs:
  cherry-pick:
    runs-on: ubuntu-latest
    if: |
      github.event.issue.pull_request != null &&
      github.event.issue.pull_request.merged_at != null &&
      (github.event.comment.body == '/cherry-pick' ||
       startsWith(github.event.comment.body, '/cherry-pick '))
    steps:
      - name: Check permission
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          COMMENTER: ${{ github.event.comment.user.login }}
        run: |
          PR_DATA=$(gh pr view "${{ github.event.issue.number }}" \
            --repo "${{ github.repository }}" \
            --json author,reviews,mergedBy)

          if ! echo "$PR_DATA" | jq -e --arg user "$COMMENTER" '
            .author.login == $user or
            (.mergedBy.login // "") == $user or
            ([ .reviews[].author.login ] | index($user)) != null
          ' > /dev/null; then
            gh api \
              --method POST \
              -H "Accept: application/vnd.github+json" \
              "/repos/${{ github.repository }}/issues/${{ github.event.issue.number }}/comments" \
              -f body="@${COMMENTER} ⛔ You don't have permission to trigger a cherry-pick. Only the PR author, reviewers, or the person who merged the PR can use this command."
            exit 1
          fi

      - name: Parse command
        id: parse
        env:
          COMMENT_BODY: ${{ github.event.comment.body }}
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          COMMENTER: ${{ github.event.comment.user.login }}
        run: |
          # Extract required branch argument
          TARGET_BRANCH=$(echo "$COMMENT_BODY" | sed 's|^/cherry-pick[[:space:]]*||' | xargs)

          if [ -z "$TARGET_BRANCH" ]; then
            gh api \
              --method POST \
              -H "Accept: application/vnd.github+json" \
              "/repos/${{ github.repository }}/issues/${{ github.event.issue.number }}/comments" \
              -f body="@${COMMENTER} Please specify a target release branch, e.g. \`/cherry-pick v0.9.9-release\`."
            exit 1
          fi

          echo "target_branch=$TARGET_BRANCH" >> "$GITHUB_OUTPUT"

      - name: Get PR details
        id: pr
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          PR_NUMBER="${{ github.event.issue.number }}"
          REPO="${{ github.repository }}"

          PR_DATA=$(gh pr view "$PR_NUMBER" --repo "$REPO" \
            --json mergeCommit,title)

          MERGE_COMMIT=$(echo "$PR_DATA" | jq -r '.mergeCommit.oid // empty')
          PR_TITLE=$(echo "$PR_DATA" | jq -r '.title')

          echo "merge_commit=$MERGE_COMMIT" >> "$GITHUB_OUTPUT"
          echo "pr_title=$PR_TITLE" >> "$GITHUB_OUTPUT"

      - name: Validate target branch
        id: branch
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          INPUT_TARGET: ${{ steps.parse.outputs.target_branch }}
          COMMENTER: ${{ github.event.comment.user.login }}
        run: |
          TARGET="$INPUT_TARGET"

          # Verify the specified branch exists
          if ! gh api "/repos/${{ github.repository }}/branches/$TARGET" > /dev/null 2>&1; then
            gh api \
              --method POST \
              -H "Accept: application/vnd.github+json" \
              "/repos/${{ github.repository }}/issues/${{ github.event.issue.number }}/comments" \
              -f body="@${COMMENTER} ❌ Cannot cherry-pick: Branch \`$TARGET\` does not exist in this repository."
            exit 1
          fi

          echo "target=$TARGET" >> "$GITHUB_OUTPUT"

      - name: Post acknowledgement comment
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          TARGET_BRANCH: ${{ steps.branch.outputs.target }}
          COMMENTER: ${{ github.event.comment.user.login }}
        run: |
          gh api \
            --method POST \
            -H "Accept: application/vnd.github+json" \
            "/repos/${{ github.repository }}/issues/${{ github.event.issue.number }}/comments" \
            -f "body=@${COMMENTER} 🍒 Attempting to cherry-pick to \`${TARGET_BRANCH}\`…"

      - name: Checkout repository
        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
        with:
          fetch-depth: 0
          token: ${{ secrets.GITHUB_TOKEN }}

      - name: Configure git
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"

      - name: Cherry-pick commit
        id: cherry_pick
        env:
          MERGE_COMMIT: ${{ steps.pr.outputs.merge_commit }}
          TARGET_BRANCH: ${{ steps.branch.outputs.target }}
          PR_NUMBER: ${{ github.event.issue.number }}
        run: |
          NEW_BRANCH="cherry-pick-${PR_NUMBER}-to-${TARGET_BRANCH}"

          git fetch origin "$TARGET_BRANCH"
          git checkout -b "$NEW_BRANCH" "origin/$TARGET_BRANCH"

          if git cherry-pick -x "$MERGE_COMMIT"; then
            echo "success=true" >> "$GITHUB_OUTPUT"
          else
            echo "success=false" >> "$GITHUB_OUTPUT"
            git cherry-pick --abort || true
          fi

          echo "new_branch=$NEW_BRANCH" >> "$GITHUB_OUTPUT"

      - name: Push branch and create PR
        if: steps.cherry_pick.outputs.success == 'true'
        id: create_pr
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          NEW_BRANCH: ${{ steps.cherry_pick.outputs.new_branch }}
          TARGET_BRANCH: ${{ steps.branch.outputs.target }}
          PR_NUMBER: ${{ github.event.issue.number }}
          PR_TITLE: ${{ steps.pr.outputs.pr_title }}
          COMMENTER: ${{ github.event.comment.user.login }}
          COMMENT_URL: ${{ github.event.comment.html_url }}
        run: |
          git push origin "$NEW_BRANCH"

          PR_BODY=$(printf 'Cherry-pick of #%s to `%s`.\n\nTriggered by @%s via [comment](%s).' \
            "$PR_NUMBER" "$TARGET_BRANCH" "$COMMENTER" "$COMMENT_URL")

          PR_URL=$(gh pr create \
            --repo "${{ github.repository }}" \
            --base "$TARGET_BRANCH" \
            --head "$NEW_BRANCH" \
            --title "[$TARGET_BRANCH] $PR_TITLE" \
            --body "$PR_BODY")

          echo "pr_url=$PR_URL" >> "$GITHUB_OUTPUT"

      - name: Comment success
        if: steps.cherry_pick.outputs.success == 'true'
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          TARGET_BRANCH: ${{ steps.branch.outputs.target }}
          NEW_PR_URL: ${{ steps.create_pr.outputs.pr_url }}
          COMMENTER: ${{ github.event.comment.user.login }}
        run: |
          gh api \
            --method POST \
            -H "Accept: application/vnd.github+json" \
            "/repos/${{ github.repository }}/issues/${{ github.event.issue.number }}/comments" \
            -f "body=@${COMMENTER} ✅ Cherry-pick to \`${TARGET_BRANCH}\` succeeded! New PR created: ${NEW_PR_URL}"

      - name: Comment conflict
        if: steps.cherry_pick.outputs.success == 'false'
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          MERGE_COMMIT: ${{ steps.pr.outputs.merge_commit }}
          TARGET_BRANCH: ${{ steps.branch.outputs.target }}
          PR_NUMBER: ${{ github.event.issue.number }}
          COMMENTER: ${{ github.event.comment.user.login }}
        run: |
          MANUAL_STEPS="git fetch origin"
          MANUAL_STEPS+=$'\n'"git checkout -b cherry-pick-${PR_NUMBER}-to-${TARGET_BRANCH} origin/${TARGET_BRANCH}"
          MANUAL_STEPS+=$'\n'"git cherry-pick -x ${MERGE_COMMIT}"
          MANUAL_STEPS+=$'\n'"# resolve conflicts, then:"
          MANUAL_STEPS+=$'\n'"git cherry-pick --continue"
          MANUAL_STEPS+=$'\n'"git push origin cherry-pick-${PR_NUMBER}-to-${TARGET_BRANCH}"
          CONFLICT_BODY=$(printf '@%s ⚠️ Cherry-pick to `%s` failed due to conflicts. Please resolve them manually:\n\n```bash\n%s\n```\n\nThen open a PR from `cherry-pick-%s-to-%s` to `%s`.' \
            "$COMMENTER" "$TARGET_BRANCH" "$MANUAL_STEPS" "$PR_NUMBER" "$TARGET_BRANCH" "$TARGET_BRANCH")
          gh api \
            --method POST \
            -H "Accept: application/vnd.github+json" \
            "/repos/${{ github.repository }}/issues/${{ github.event.issue.number }}/comments" \
            -f "body=$CONFLICT_BODY"
          exit 1