zerops.yaml

zerops:
  # Production setup — install deps to ./vendor, compile nothing,
  # deploy minimal artifact. Flask + Gunicorn serve production traffic.
  - setup: prod
    build:
      base: python@3.11

      buildCommands:
        # Install all dependencies into ./vendor so they travel
        # with the application artifact to the runtime container.
        # --target keeps packages inside the project tree (no
        # system-Python pollution) — matches cache and deployFiles.
        - pip install --target=./vendor -r requirements.txt

      deployFiles:
        - ./src        # Flask application package
        - ./vendor     # All pip-installed packages
        - ./migrate.py # DB migration script (runs in initCommands)

      # Reuse ./vendor across builds — pip skips packages already
      # present, cutting subsequent build times significantly.
      cache:
        - vendor

    # Readiness check: Zerops probes GET / before adding the new
    # container to the project balancer — guarantees zero-downtime
    # deploys only route traffic to fully-started containers.
    deploy:
      readinessCheck:
        httpGet:
          port: 8000
          path: /

    run:
      base: python@3.11

      # Run DB migration once per deploy version. initCommands —
      # not buildCommands — ensures migration and code are deployed
      # atomically. zsc execOnce prevents race conditions when
      # multiple containers start simultaneously.
      initCommands:
        - zsc execOnce ${appVersionId} --retryUntilSuccessful -- python migrate.py

      ports:
        - port: 8000
          httpSupport: true

      envVariables:
        # Point Python's module search to the deployed vendor dir.
        PYTHONPATH: /var/www/vendor
        DB_NAME: db
        # Zerops generates these from the 'db' service hostname:
        # ${hostname_key} syntax references generated env variables.
        DB_HOST: ${db_hostname}
        DB_PORT: ${db_port}
        DB_USER: ${db_user}
        DB_PASS: ${db_password}

      # Gunicorn is the production WSGI server. Two workers handle
      # concurrent requests; Flask's built-in server is single-threaded
      # and not suitable for production traffic.
      start: >-
        /var/www/vendor/bin/gunicorn
        --bind 0.0.0.0:8000
        --workers 2
        src.app:app

  # Development setup — deploy full source for SSH-based iteration.
  # The developer SSHs in, runs the app manually, and edits files
  # in place. Zerops prepares the workspace; the developer drives.
  - setup: dev
    build:
      base: python@3.11

      buildCommands:
        # Same vendoring as prod — ./vendor ships with deployFiles: ./
        # so the developer has all dependencies ready after SSH without
        # running pip manually.
        - pip install --target=./vendor -r requirements.txt

      # Deploy the entire working directory — source, vendor, and
      # zerops.yaml (needed if the developer runs zcli push from SSH).
      deployFiles:
        - ./

      cache:
        - vendor

    run:
      base: python@3.11

      # Migration runs on deploy — database is ready when developer
      # SSHs in, no manual setup needed.
      initCommands:
        - zsc execOnce ${appVersionId} --retryUntilSuccessful -- python migrate.py

      ports:
        - port: 8000
          httpSupport: true

      envVariables:
        PYTHONPATH: /var/www/vendor
        DB_NAME: db
        DB_HOST: ${db_hostname}
        DB_PORT: ${db_port}
        DB_USER: ${db_user}
        DB_PASS: ${db_password}

      # zsc noop keeps the container alive without starting the app —
      # the developer starts Flask or Gunicorn manually after SSH.
      # Example: /var/www/vendor/bin/gunicorn --bind 0.0.0.0:8000
      #          --workers 2 src.app:app
      start: zsc noop --silent