create-release-tag.yml

name: Create Release Tag

on:
  workflow_dispatch:
    inputs:
      release_ref:
        description: Git ref to tag
        required: true
        default: main

permissions:
  contents: write

env:
  git_user_name: localstack[bot]
  git_user_email: localstack-bot@users.noreply.github.com

concurrency:
  group: create-release-tag
  cancel-in-progress: false

jobs:
  create-tag:
    name: Create next CalVer tag
    runs-on: ubuntu-latest
    steps:
      - name: Checkout code
        uses: actions/checkout@v6
        with:
          ref: ${{ inputs.release_ref }}
          fetch-depth: 0

      - name: Configure Git user
        env:
          GIT_USER_NAME: ${{ env.git_user_name }}
          GIT_USER_EMAIL: ${{ env.git_user_email }}
        run: |
          git config user.name "${GIT_USER_NAME}"
          git config user.email "${GIT_USER_EMAIL}"

      - name: Fetch tags
        run: git fetch --tags --force

      - name: Compute next CalVer tag
        id: next_tag
        run: |
          set -euo pipefail
          year="$(date -u +%Y)"
          month="$(date -u +%-m)"
          prefix="${year}.${month}."

          latest="$(git tag --list "${prefix}*" --sort=-v:refname | grep -E "^${year}\.${month}\.[0-9]+$" | head -n 1 || true)"
          if [[ -z "${latest}" ]]; then
            patch=0
          else
            patch="$(( ${latest##*.} + 1 ))"
          fi

          tag="${year}.${month}.${patch}"
          if git rev-parse -q --verify "refs/tags/${tag}" >/dev/null; then
            echo "Tag ${tag} already exists"
            exit 1
          fi

          echo "tag=${tag}" >> "${GITHUB_OUTPUT}"

      - name: Create and push tag
        run: |
          tag="${{ steps.next_tag.outputs.tag }}"
          git tag -a "${tag}" -m "Release ${tag}"
          git push origin "${tag}"

      - name: Print created tag
        run: echo "Created tag ${{ steps.next_tag.outputs.tag }}"