services:
  probe:
    image: ${PROBE_IMAGE:?set a pinned image digest}
    ports:
      - "127.0.0.1:${PROBE_PORT:-18080}:18080"
    volumes:
      - containers-state:/tmp/containers-state
    healthcheck:
      test: ["CMD", "python3", "-c", "import urllib.request; urllib.request.urlopen('http://127.0.0.1:18080/ready', timeout=2)"]
      interval: 5s
      timeout: 3s
      retries: 3
volumes:
  containers-state: