action.yml

name: 'BlueBuild'
description: 'Build a custom OS image'
inputs:
  recipe:
    description: |
      The [recipe](https://blue-build.org/reference/recipe/) file to build the image from, relative to the `config/` or `recipes/` directory.
    required: true
    default: 'recipe.yml'
  cosign_private_key:
    description: |
      The Sigstore/cosign secret used to sign the image.

      Example: `${{ secrets.SIGNING_SECRET }}`
    required: true
  registry_token:
    description: | 
      The token used to sign into the container registry.

      Example: `${{ github.token }}`
    required: false
    default: ''
  registry_username:
    description: | 
      The username used to sign into the container registry.
    required: false
    default: ${{ github.repository_owner }}
  pr_event_number:
    description: |
      The event number used to tag images pushed from pull requests.

      Example: `${{ github.event.number }}`
    required: true
  maximize_build_space:
    description: |
      Whether to run the unwanted software remover to maximize build space in the GitHub builder.
      Disable this with 'false' if your image doesn't take up a lot of space and you'd rather have shorter build times.
    required: false
    default: 'true'
  use_unstable_cli:
    description: |
      If true, this action pulls the `main` branch of blue-build/cli instead of the stable version the current action version is configured to use by default. 
      This feature is useful for testing new features, but should not be used in production.
      Input must match the string 'true' for the unstable version to be used.
    required: false
    default: 'false'
  cli_version:
    description: |
      Set this with a tag, sha, or branch name for the blue-build/cli repo to use that particular version of the CLI tool. This will override the `use_unstable_cli` input for the action.
    required: false
  registry:
    description: |
      The container registry to push the built image to.
    required: false
    default: 'ghcr.io'
  registry_namespace:
    description: |
     The namespace on the registry to push to.
     
     Example: `ublue-os`
    required: false
    default: ${{ github.repository_owner }}
  use_cache:
    description: |
      Make use of docker buildx cache. This is an experimental feature of docker buildx
      so it isn't guaranteed to work.
      Input must match the string 'true' for the step to be enabled.
    required: false
    default: 'true'
  squash:
    description: |
      Uses buildah to squash the build's layers into a single layer. Use of this option
      disables cache.
    required: false
    default: 'false'
  working_directory:
    description: |
      Changes working directory for whole build.
      For example, setting this to `./abc/` would cause for the recipe to be read from `./abc/recipes/recipe.yml`.
    required: false
    default: ./
  skip_checkout:
      description: |
        Set to true to skip doing the actions/checkout step.
        This allows you to checkout manually before calling bluebuild/github-action
        and to modify files (such as supplying build information to other scripts) before building.
      required: false
      default: 'false'

runs:
  using: "composite"
  steps:
    # building custom images might take a lot of space, 
    # so it's best to remove unneeded softawre
    - name: Maximize build space
      uses: jlumbroso/free-disk-space@v1.3.1
      if: ${{ inputs.maximize_build_space == 'true' }}

    - name: Set up Docker Buildx
      uses: docker/setup-buildx-action@v3
      if: ${{ inputs.squash != 'true' }}
      with:
        install: true
        driver: docker-container
        cache-binary: ${{ inputs.use_cache }}

    - name: Get Ubuntu version
      id: ubuntu_version
      shell: bash
      run: |
        VERSION=$(awk -F= '/^VERSION_ID=/ {gsub(/"/, "", $2); print $2}' /etc/os-release)
        echo "Ubuntu version is $VERSION"
        echo "version=$VERSION" >> $GITHUB_OUTPUT

    # that is compatible with BlueBuild
    - name: Setup Podman
      if: ${{ inputs.squash == 'true' && steps.ubuntu_version.outputs.version == '22.04' }}
      shell: bash
      run: |
        # from https://askubuntu.com/questions/1414446/whats-the-recommended-way-of-installing-podman-4-in-ubuntu-22-04
        ubuntu_version='22.04'
        key_url="https://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/unstable/xUbuntu_${ubuntu_version}/Release.key"
        sources_url="https://download.opensuse.org/repositories/devel:/kubic:/libcontainers:/unstable/xUbuntu_${ubuntu_version}"
        echo "deb $sources_url/ /" | sudo tee /etc/apt/sources.list.d/devel-kubic-libcontainers-unstable.list
        curl -fsSL $key_url | gpg --dearmor | sudo tee /etc/apt/trusted.gpg.d/devel_kubic_libcontainers_unstable.gpg > /dev/null
        sudo apt-get update
        sudo apt-get install -y podman

    - uses: sigstore/cosign-installer@v3.7.0

    # clones user's repo
    - uses: actions/checkout@v4
      if: ${{ inputs.skip_checkout == 'false' }}

    - name: Determine Vars
      id: build_vars
      shell: bash
      env:
        RECIPE: ${{ inputs.recipe }}
      run: |
        if [[ "${{ inputs.use_unstable_cli }}" == "true" && -z "${{ inputs.cli_version }}" ]]; then
          CLI_VERSION_TAG="main"
        elif [ -n "${{ inputs.cli_version }}" ]; then
          CLI_VERSION_TAG="${{ inputs.cli_version }}"
        else
          CLI_VERSION_TAG="v0.8"
        fi
        echo "cli_version=${CLI_VERSION_TAG}" >> ${GITHUB_OUTPUT}

        RECIPE_PATH=""
        if [ -f "./config/${RECIPE}" ]; then
          RECIPE_PATH="./config/${RECIPE}"
        else
          RECIPE_PATH="./recipes/${RECIPE}"
        fi
        echo "recipe_path=${RECIPE_PATH}" >> ${GITHUB_OUTPUT}

    - name: Install BlueBuild
      shell: bash
      env:
        CLI_VERSION_TAG: ${{ steps.build_vars.outputs.cli_version }}
      run: |
        docker create \
          --name blue-build-installer \
          ghcr.io/blue-build/cli:${{ env.CLI_VERSION_TAG }}-installer
        docker cp blue-build-installer:/out/bluebuild /usr/local/bin/bluebuild
        docker rm blue-build-installer
        bluebuild --version

    # Required in order for docker buildx to
    # take advantage of the GHA cache API
    - name: Expose GitHub Runtime
      if: ${{ inputs.use_cache == 'true' && inputs.squash != 'true' }}
      uses: crazy-max/ghaction-github-runtime@v3


    # blue-build/cli does the heavy lifting
    - name: Build Image
      shell: bash
      working-directory: ${{ inputs.working_directory }}
      env:
        COSIGN_PRIVATE_KEY: ${{ inputs.cosign_private_key }}
        GH_TOKEN: ${{ inputs.registry_token }}
        BB_PASSWORD: ${{ inputs.registry_token }}
        BB_USERNAME: ${{ inputs.registry_username }}
        BB_REGISTRY: ${{ inputs.registry }}
        BB_REGISTRY_NAMESPACE: ${{ inputs.registry_namespace }}
        GH_PR_EVENT_NUMBER: ${{ inputs.pr_event_number }}
        BB_BUILDKIT_CACHE_GHA: ${{ inputs.use_cache }}
        RECIPE_PATH: ${{ steps.build_vars.outputs.recipe_path }}
        RUST_LOG_STYLE: always
        CLICOLOR_FORCE: '1'
      run: |
        BUILD_OPTS=""

        if [ "${{ inputs.squash }}" = "true" ]; then
          BUILD_OPTS="--build-driver podman --squash $BUILD_OPTS"
        fi

        bluebuild build -v --push ${BUILD_OPTS} ${RECIPE_PATH}