pipelines/docker-update.yml

---
steps:    
  - label: "Docker build and push"
    agents:
      - "queue=default"
    plugins:
      docker#v3.8.0:
        always-pull: true
        environment:
          - ANDROID_HOME
          - ANDROID_NDK_HOME
          - BUILDKITE_ARTIFACT_UPLOAD_DESTINATION
        image: gcr.io/bazel-public/ubuntu2004
        network: host
        privileged: true
        propagate-environment: true
        propagate-uid-gid: true
        shell: ["/bin/bash", "-e", "-c"]
        volumes:
          - "/etc/group:/etc/group:ro"
          - "/etc/passwd:/etc/passwd:ro"
          - "/etc/shadow:/etc/shadow:ro"
          - "/opt/android-ndk-r15c:/opt/android-ndk-r15c:ro"
          - "/opt/android-sdk-linux:/opt/android-sdk-linux:ro"
          - "/var/lib/buildkite-agent:/var/lib/buildkite-agent"
          - "/var/lib/gitmirrors:/var/lib/gitmirrors:ro"
          - "/var/run/docker.sock:/var/run/docker.sock"    
    command: |
      echo "+++ Checking out Git branch"
      git fetch origin ${BUILDKITE_BRANCH}
      git checkout ${BUILDKITE_BRANCH}
      
      echo "release_name = \"\$release_name\""            
      version=$(echo $release_name | sed 's/release-//g')
      echo "version = \"\$version\""  
      
      echo "+++ Building the docker container"
      ./bazel/oci/build.sh gcr.io/bazel-public/bazel \${version}

      echo "+++ Pushing the docker container to gcr.io/bazel-public/bazel"     
      docker push gcr.io/bazel-public/bazel:\${version}
      
      echo "+++ Determining if this is the highest semantic version"
      # Fetch the current "latest" tag name from GitHub

      latest_release_url=$(curl -Ls -o /dev/null -w %{url_effective} https://github.com/bazelbuild/bazel/releases/latest)
      latest_release_tag=$(basename \${latest_release_url})
      echo "latest_release_tag = \"\$latest_release_tag\""
      
      # Using version-sort to find the highest version between current and GitHub-latest
      highest_version=$(printf '%s\n%s' "\$version" "\$latest_release_tag" | sort -V | tail -n 1)
      echo "highest_version = \"\$highest_version\""

      if [[ \"\$version\" == \"\$highest_version\" ]]; then
        echo "+++ Updating the latest tag to \${version}"
        image_id=$(docker image list gcr.io/bazel-public/bazel:\${version} --format \"{{.ID}}\")        
        image_id=$(echo \${image_id} | tr -d '"')
        docker tag \${image_id} gcr.io/bazel-public/bazel:latest
        docker push gcr.io/bazel-public/bazel:latest
      else
        echo "--- Skipping latest tag update (Version \${version} is older than \${latest_release_tag})"
      fi