_shared-docker-clone.yaml

name: Reusable docker clone workflow
on:
  workflow_call:
    inputs:
      source_repository:
        description: 'Source Docker Hub Repository'
        default: ''
        required: false
        type: string
      target_repository:
        description: 'Target Docker Hub Repository'
        default: ''
        required: false
        type: string
      tags:
        description: 'Docker Image Tags (JSON)'
        default: ''
        required: false
        type: string
    secrets:
      DOCKERHUB_USERNAME:
        description: 'Docker Hub Username'
        required: false
      DOCKERHUB_TOKEN:
        description: 'Docker Hub Token'
        required: false

# shared build jobs
jobs:
  clone_docker_images:
    name: Clone docker images to ${{ inputs.target_repository }}
    if: ${{ inputs.tags }}
    runs-on: ubuntu-latest
    strategy:
      matrix:
        tag: ${{ fromJSON(inputs.tags) }}
    steps:

    # prepare docker
    - name: Set up Docker Buildx
      uses: docker/setup-buildx-action@v2
    - name: Login to Docker Hub
      uses: docker/login-action@v2
      with:
        username: ${{ secrets.DOCKERHUB_USERNAME }}
        password: ${{ secrets.DOCKERHUB_TOKEN }}
    
    - name: Get tag names
      id: tags
      run: |
        tagstr="${{ matrix.tag }}"
        tagparts=(${tagstr//:/ })
        echo "source_tag=${tagparts[0]}" >> $GITHUB_OUTPUT
        if [ -z "${tagparts[1]}" ]; then
          echo "target_tag=${tagparts[0]}" >> $GITHUB_OUTPUT
        else
          echo "target_tag=${tagparts[1]}" >> $GITHUB_OUTPUT
        fi

    # build multiarch image
    - name: "Copy docker image: ${{ steps.tags.outputs.target_tag }}"
      run: |
        docker buildx imagetools create -t ${{ inputs.target_repository }}:${{ steps.tags.outputs.target_tag }} \
         ${{ inputs.source_repository }}:${{ steps.tags.outputs.source_tag }}-amd64 \
         ${{ inputs.source_repository }}:${{ steps.tags.outputs.source_tag }}-arm64