release-cut.yml

# Copyright 2026 Google LLC
#
# 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
#
#     http://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.

# Unified release manager. Supports:
# 1. Cutting a new release candidate branch from main or v1.
# 2. Regenerating/updating the changelog PR on an existing candidate branch.
name: "Release: Cut"

on:
  workflow_dispatch:
    inputs:
      action:
        description: 'Action to perform'
        required: true
        default: 'cut'
        type: choice
        options:
          - cut
          - regenerate
      branch:
        description: 'Branch to release from (main or v1)'
        required: true
        default: 'main'
        type: choice
        options:
          - main
          - v1
      commit_sha:
        description: 'Optional Commit SHA (only used for "cut" action; overrides branch latest)'
        required: false
        type: string

permissions:
  contents: write
  pull-requests: write

jobs:
  cut-or-regenerate:
    runs-on: ubuntu-latest
    steps:
      - name: Determine Branch Configurations
        id: config
        run: |
          BRANCH="${{ inputs.branch }}"
          if [ "$BRANCH" = "v1" ]; then
            echo "base_ref=v1" >> $GITHUB_OUTPUT
            echo "candidate_branch=release/v1-candidate" >> $GITHUB_OUTPUT
            echo "config_file=.github/release-please-config-v1.json" >> $GITHUB_OUTPUT
            echo "manifest_file=.github/.release-please-manifest-v1.json" >> $GITHUB_OUTPUT
          else
            echo "base_ref=main" >> $GITHUB_OUTPUT
            echo "candidate_branch=release/candidate" >> $GITHUB_OUTPUT
            echo "config_file=.github/release-please-config.json" >> $GITHUB_OUTPUT
            echo "manifest_file=.github/.release-please-manifest.json" >> $GITHUB_OUTPUT
          fi

      # Action: CUT NEW RELEASE
      - name: Checkout base ref (Cut)
        if: inputs.action == 'cut'
        uses: actions/checkout@v6
        with:
          ref: ${{ inputs.commit_sha || steps.config.outputs.base_ref }}
          token: ${{ secrets.RELEASE_PAT }}

      - name: Check for existing candidate branch (Cut)
        if: inputs.action == 'cut'
        run: |
          CANDIDATE_BRANCH="${{ steps.config.outputs.candidate_branch }}"
          if git ls-remote --exit-code --heads origin "$CANDIDATE_BRANCH" &>/dev/null; then
            echo "Error: Branch $CANDIDATE_BRANCH already exists."
            echo "Please finalize or delete the existing release candidate before starting a new one."
            exit 1
          fi

      - name: Create and push candidate branch (Cut)
        if: inputs.action == 'cut'
        run: |
          CANDIDATE_BRANCH="${{ steps.config.outputs.candidate_branch }}"
          git checkout -b "$CANDIDATE_BRANCH"
          git push origin "$CANDIDATE_BRANCH"
          echo "Created and pushed branch: $CANDIDATE_BRANCH"

      # Action: REGENERATE EXISTING PR
      - name: Checkout existing candidate branch (Regenerate)
        if: inputs.action == 'regenerate'
        uses: actions/checkout@v6
        with:
          ref: ${{ steps.config.outputs.candidate_branch }}
          token: ${{ secrets.RELEASE_PAT }}

      # Run Release Please
      - name: Run Release Please
        uses: googleapis/release-please-action@v4
        with:
          token: ${{ secrets.RELEASE_PAT }}
          config-file: ${{ steps.config.outputs.config_file }}
          manifest-file: ${{ steps.config.outputs.manifest_file }}
          target-branch: ${{ steps.config.outputs.candidate_branch }}