action.yml

name: Build Docker Image
description: Builds and pushes the app image for a Control Plane workload

inputs:
  app_name:
    description: Name of the application
    required: true
  org:
    description: Control Plane organization name
    required: true
  commit:
    description: Commit SHA to tag the image with
    required: true
  pr_number:
    description: Pull request number for status messaging
    required: false
  docker_build_extra_args:
    description: Optional newline-delimited extra arguments passed through to docker build
    required: false
  docker_build_ssh_key:
    description: Optional private SSH key used for Docker builds that fetch private dependencies with RUN --mount=type=ssh
    required: false

outputs:
  image_tag:
    description: Fully qualified image tag
    value: ${{ steps.build.outputs.image_tag }}

runs:
  using: composite
  steps:
    - name: Build Docker image
      id: build
      shell: bash
      run: |
        set -euo pipefail

        PR_INFO=""
        docker_build_args=()

        if [[ -n "${{ inputs.pr_number }}" ]]; then
          PR_INFO=" for PR #${{ inputs.pr_number }}"
        fi

        if [[ -n "${{ inputs.docker_build_extra_args }}" ]]; then
          while IFS= read -r arg; do
            arg="${arg%$'\r'}"
            [[ -n "${arg}" ]] || continue
            docker_build_args+=("${arg}")
          done <<< "${{ inputs.docker_build_extra_args }}"
        fi

        if [[ -n "${{ inputs.docker_build_ssh_key }}" ]]; then
          mkdir -p ~/.ssh
          chmod 700 ~/.ssh
          ssh-keyscan -H github.com >> ~/.ssh/known_hosts
          chmod 600 ~/.ssh/known_hosts

          eval "$(ssh-agent -s)"
          trap 'ssh-agent -k >/dev/null' EXIT
          ssh-add - <<< "${{ inputs.docker_build_ssh_key }}"
          docker_build_args+=("--ssh default")
        fi

        echo "🏗️ Building Docker image${PR_INFO} (commit ${{ inputs.commit }})..."
        cpflow build-image -a "${{ inputs.app_name }}" --commit="${{ inputs.commit }}" --org="${{ inputs.org }}" "${docker_build_args[@]}"

        image_tag="${{ inputs.org }}/${{ inputs.app_name }}:${{ inputs.commit }}"
        echo "image_tag=${image_tag}" >> "$GITHUB_OUTPUT"
        echo "✅ Docker image build successful${PR_INFO} (commit ${{ inputs.commit }})"