sample

gistfile1.txt

jobs:
  publish_docker_linux:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      packages: write
    strategy:
      fail-fast: false
      matrix:
        include:
        - os: linux
          arch: x64
        - os: linux
          arch: arm64
    env:
      ContainerImageTagSuffix: ${{ matrix.os }}-${{ matrix.arch }}
    steps:
    - uses: actions/checkout@v6
  
    - name: Setup .NET SDK
      uses: actions/setup-dotnet@v5

    - name: run tests
      run: dotnet test

    - uses: actions/upload-artifact@v7
      if: always()
      with:
        name: test-results-${{ matrix.os }}-${{ matrix.arch }}
        path: '**/TestResults/**/*'

    - run: docker run --privileged --rm tonistiigi/binfmt --install all
  
    - name: Log in to Docker
      uses: docker/login-action@v4
      with:
        registry: ${{ env.ContainerRegistry }}
        username: ${{ github.actor }}
        password: ${{ secrets.GITHUB_TOKEN }}

    - name: run local docker registry
      run: docker run -d -p 5000:5000 --name registry registry:latest
      
    - name: Build base image
      working-directory: Test.BaseImage
      run: |
          $platform = "${{ matrix.os }}/${{ matrix.arch }}".replace('x64', 'amd64')
          docker build --tag localhost:5000/test-base:latest-${{env.ContainerImageTagSuffix}} --platform $platform --file Dockerfile .
      
    - name: push base image
      working-directory: test.BaseImage
      run: docker push localhost:5000/test-base:latest-${{env.ContainerImageTagSuffix}}
        
    - name: Create image
      run: dotnet publish test.csproj --os ${{matrix.os}} --arch ${{matrix.arch}} --configuration Release /t:PublishContainer
      
  publish_multiarch:
    runs-on: ubuntu-latest
    permissions:
        contents: read
        packages: write
    needs: [publish_docker_linux]
    steps:  
      - name: Log in to Docker
        uses: docker/login-action@v4
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}
      - run: | 
          $image = "${{env.ContainerRegistry}}/${{env.ContainerRepository}}:${{env.ContainerImageTags}}"
          Write-Host "Pushing image $image"
          docker manifest create $image "${image}-linux-x64" "${image}-linux-arm64"
          docker manifest push "$image"

gistfile2.txt

 <ContainerBaseImage>localhost:5000/test-base:latest-$(ContainerImageTagSuffix)</ContainerBaseImage>
    <ContainerImageTags>$(ContainerImageTags)-$(ContainerImageTagSuffix);latest-$(ContainerImageTagSuffix)</ContainerImageTags>