action.yml

name: "wolfi-act"
description: "Dynamic GitHub Actions from Wolfi packages"
inputs:
  packages:
    description: "Comma-separated list of Wolfi packages to install"
    required: true
  command:
    description: "Command to run"
    required: true
  apko-image:
    description: "The apko image to build with"
    required: true
    default: "cgr.dev/chainguard/apko:latest"
  debug:
    description: "Whether or not to add debug logging"
    required: false
    default: 'false'

runs:
  using: "composite"
  steps:
    - shell: bash
      env:
        INPUT_DEBUG: ${{ inputs.debug }}
        INPUT_COMMAND: ${{ inputs.command }}
        INPUT_PACKAGES: ${{ inputs.packages }}
        INPUT_APKO_IMAGE: ${{ inputs.apko-image }}
      run: |
        set -e

        debug_args=
        debug_args_image="-exc"
        debug="${INPUT_DEBUG}"
        if [[ "${debug}" == "true" ]]; then
          echo "[🐙] Enabling debug logging."
          set -x
          debug_args="2>/dev/null"
          debug_args_image="-ec"
        fi

        if [[ "${INPUT_COMMAND}" == '' ]]; then
          echo "[🐙] Missing input: command"
          exit 1
        fi

        cat >./wolfi-act.apko.config.yaml <<EOL
        contents:
          repositories:
            - https://packages.wolfi.dev/os
          keyring:
            - https://packages.wolfi.dev/os/wolfi-signing.rsa.pub
          packages:
            - ca-certificates-bundle
            - wolfi-baselayout
            - busybox
            - bash
        EOL

        packages="${INPUT_PACKAGES}"
        if [[ "${packages}" != "" ]]; then
          for package in $(echo "${packages}" | sed 's/,/\n/g'); do
            echo "    - ${package}" >> ./wolfi-act.apko.config.yaml
          done
        fi

        printf "[🐙] Building ephemeral container image from Wolfi packages... "
        eval docker run --rm \
            -v "${PWD}":/work \
            -w /work \
            "${INPUT_APKO_IMAGE}" \
            build \
            --arch=x86_64 \
            --sbom=false \
            wolfi-act.apko.config.yaml \
            wolfi-act:latest \
            wolfi-act.tar "${debug_args}"

        echo "done."

        printf "[🐙] Loading ephemeral container image into Docker... "
        eval docker load < wolfi-act.tar "${debug_args}"
        echo "done."

        # Capture runner env for the container, excluding INPUT_* vars and
        # any var whose value contains embedded newlines (which no
        # line-oriented env file format can represent). env -0 gives
        # null-terminated records so multi-line values stay in one record;
        # we read them in a while loop to avoid grep -v exit-code-1 when
        # no records are filtered, which kills the pipeline under pipefail.
        while IFS= read -r -d '' record; do
          name="${record%%=*}"
          value="${record#*=}"
          [[ "$name" == INPUT_* ]] && continue
          [[ "$value" == *$'\n'* ]] && continue
          printf '%s\n' "$record"
        done < <(env -0) > wolfi-act.github.env

        echo "[🐙] Running the following command in ephemeral container image:"
        echo "${INPUT_COMMAND}"
        echo "[🐙] Output:"
        docker run -i --rm --platform linux/amd64 \
            -v "${PWD}":/work \
            -w /work \
            --env-file wolfi-act.github.env \
            wolfi-act:latest-amd64 \
            bash "${debug_args_image}" "${INPUT_COMMAND}"