update-docker-latest.yml

name: Promote Docker Tag to Latest

on:
  workflow_dispatch:
    inputs:
      tag:
        description: "Existing tag to promote to latest (e.g. 7.1.0)"
        required: true
        type: string

env:
  REGISTRY: docker.io
  IMAGE_NAME: predic8/membrane

jobs:
  promote-latest:
    runs-on: ubuntu-latest
    permissions:
      contents: read

    steps:
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3

      - name: Log in to Docker Hub
        uses: docker/login-action@v3
        with:
          registry: ${{ env.REGISTRY }}
          username: ${{ secrets.DOCKER_HUB_USER }}
          password: ${{ secrets.DOCKER_HUB_PASS }}

      - name: Validate source tag exists
        run: |
          docker buildx imagetools inspect \
            "${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ inputs.tag }}"

      - name: Promote tag to latest
        run: |
          SRC="${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ inputs.tag }}"
          DST="${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest"

          docker buildx imagetools create --tag "$DST" "$SRC"

      - name: Verify latest
        run: |
          docker buildx imagetools inspect \
            "${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:latest"