action.yml

name: "Preview Environments for GitHub"
description: "Ephemeral preview deployments of your app for every pull request. Just using Docker Compose."
author: "Cyril Rohr"
branding:
  icon: anchor
  color: purple
inputs:
  app_path:
    description: "The path to your application containing a docker-compose file"
    default: "."
    required: false
  dns:
    description: "Which DNS suffix to use"
    default: "my.preview.run"
  max_domain_length:
    description: "Maximum length of fully qualified domain name. Note that it cannot be greater than 62 characters due to LetsEncrypt restrictions."
    default: "62"
  label:
    description: "Label to use for triggering preview deployments"
    default: "pullpreview"
  github_token:
    description: "The GitHub access token used to perform GitHub API operations (labels, comments, collaborator/keys lookup)."
    default: "${{ github.token }}"
  admins:
    description: "Logins of GitHub users that will have their SSH key installed on the instance, comma-separated"
    required: false
    default: "@collaborators/push"
  ports:
    description: "Ports to open for external access on the preview server (port 22 is always open), comma-separated"
    required: false
    default: "80/tcp,443/tcp"
  cidrs:
    description: "The IP address, or range of IP addresses in CIDR notation, that are allowed to connect to the instance"
    required: false
    default: "0.0.0.0/0"
  default_port:
    description: "The port to use when building the preview URL"
    required: false
    default: "80"
  compose_files:
    description: "Compose files to use when running docker-compose up, comma-separated"
    required: false
    default: "docker-compose.yml"
  compose_options:
    description: "Additional options to pass to docker-compose up, comma-separated"
    required: false
    default: "--build"
  license:
    description: "PullPreview license"
    required: false
    default: ""
  instance_type:
    description: "Instance type to use"
    required: false
    default: "small"
  region:
    description: "Provider region (AWS region or Hetzner location), overrides provider defaults"
    required: false
    default: ""
  deployment_variant:
    description: "Deployment variant, which allows launching multiple deployments per PR (4 chars max)"
    required: false
    default: ""
  image:
    description: "Instance image (Hetzner only; ignored by AWS)"
    required: false
    default: "ubuntu-24.04"
  provider:
    description: "Cloud provider to use: lightsail, hetzner"
    required: false
    default: "lightsail"
  registries:
    description: "Names of private registries to authenticate against. E.g. docker://username:password@ghcr.io"
    required: false
    default: ""
  proxy_tls:
    description: "Enable automatic HTTPS forwarding with Let's Encrypt (format: service:port, e.g. web:80)"
    required: false
    default: ""
  pre_script:
    description: "Path to a local bash script (relative to app_path) executed inline over SSH on the instance before docker compose"
    required: false
    default: ""
  ttl:
    description: "Maximum time to live for deployments (e.g. 10h, 5d, infinite)"
    required: false
    default: "infinite"

outputs:
  live:
    description: "Whether this run produced a live preview deployment"
    value: "${{ steps.pullpreview.outputs.live }}"
  url:
    description: "The URL of the application on the preview server"
    value: "${{ steps.pullpreview.outputs.url }}"
  host:
    description: "The hostname or IP address of the preview server"
    value: "${{ steps.pullpreview.outputs.host }}"
  username:
    description: "The username that can be used to SSH into the preview server"
    value: "${{ steps.pullpreview.outputs.username }}"

runs:
  using: "composite"
  steps:
    - name: Restore SSH key cache
      uses: actions/cache@v4
      with:
        path: ${{ runner.temp }}/pullpreview-ssh-keys
        key: pullpreview-ssh-keys-v1-${{ github.repository_id }}-${{ github.run_id }}
        restore-keys: |
          pullpreview-ssh-keys-v1-${{ github.repository_id }}-
    - id: pullpreview
      shell: bash
      env:
        GITHUB_TOKEN: "${{ inputs.github_token }}"
        PULLPREVIEW_LICENSE: "${{ inputs.license }}"
        PULLPREVIEW_PROVIDER: "${{ inputs.provider }}"
        PULLPREVIEW_MAX_DOMAIN_LENGTH: "${{ inputs.max_domain_length }}"
        PULLPREVIEW_SSH_KEYS_CACHE_DIR: "${{ runner.temp }}/pullpreview-ssh-keys"
        PULLPREVIEW_GITHUB_JOB_ID: "${{ job.check_run_id }}"
      run: |
        set -euo pipefail
        mkdir -p "${PULLPREVIEW_SSH_KEYS_CACHE_DIR}"

        os="$(echo "${RUNNER_OS}" | tr '[:upper:]' '[:lower:]')"
        arch="$(echo "${RUNNER_ARCH}" | tr '[:upper:]' '[:lower:]')"
        if [ "${os}" != "linux" ]; then
          echo "::error::Unsupported RUNNER_OS=${RUNNER_OS}. Only Linux amd64 is supported."
          exit 1
        fi
        case "${arch}" in
          x64) arch="amd64" ;;
          amd64) arch="amd64" ;;
          *)
            echo "::error::Unsupported RUNNER_ARCH=${RUNNER_ARCH}. Only amd64 is supported."
            exit 1
            ;;
        esac

        binary="${GITHUB_ACTION_PATH}/dist/pullpreview-${os}-${arch}"
        if [ ! -f "${binary}" ]; then
          echo "::error::Bundled binary not found at ${binary}. Run 'make dist' and commit dist artifacts."
          ls -la "${GITHUB_ACTION_PATH}/dist" || true
          exit 1
        fi
        chmod +x "${binary}"

        app_path="${{ inputs.app_path }}"
        # Backward compatibility for Docker-era defaults; composite actions run in $GITHUB_WORKSPACE.
        if [ -z "${app_path}" ] || [ "${app_path}" = "/github/workspace" ]; then
          app_path="${GITHUB_WORKSPACE}"
        fi

        "${binary}" github-sync "${app_path}" \
          --admins "${{ inputs.admins }}" \
          --cidrs "${{ inputs.cidrs }}" \
          --compose-files "${{ inputs.compose_files }}" \
          --compose-options "${{ inputs.compose_options }}" \
          --dns "${{ inputs.dns }}" \
          --label "${{ inputs.label }}" \
          --ports "${{ inputs.ports }}" \
          --default-port "${{ inputs.default_port }}" \
          --instance-type "${{ inputs.instance_type }}" \
          --region "${{ inputs.region }}" \
          --image "${{ inputs.image }}" \
          --deployment-variant "${{ inputs.deployment_variant }}" \
          --registries "${{ inputs.registries }}" \
          --proxy-tls "${{ inputs.proxy_tls }}" \
          --pre-script "${{ inputs.pre_script }}" \
          --ttl "${{ inputs.ttl }}"

        if grep -q '^url=' "${GITHUB_OUTPUT}"; then
          echo "live=true" >> "${GITHUB_OUTPUT}"
        else
          echo "live=false" >> "${GITHUB_OUTPUT}"
        fi