Docker SDK Python Container Healthcheck

import docker

client = docker.from_env()


def start_with_healthcheck(image: str, name: str, port: int) -> dict:
    container = client.containers.run(
        image,
        name=name,
        detach=True,
        ports={f'{port}/tcp': None},
        healthcheck={
            'test': ['CMD-SHELL', f'curl -sf http://localhost:{port}/healthz || exit 1'],
            'interval': 1_000_000_000,   # 纳秒：1 秒
            'timeout': 500_000_000,      # 纳秒：0.5 秒
            'retries': 5,
            'start_period': 3_000_000_000,
        },
        environment={'SERVICE_PORT': str(port)},
    )
    return {'id': container.short_id, 'name': name}


def wait_healthy(name: str, timeout: float = 30.0) -> bool:
    import time
    deadline = time.monotonic() + timeout

    while time.monotonic() < deadline:
        container = client.containers.get(name)
        health = container.attrs['State']['Health']['Status']
        if health == 'healthy':
            return True
        if health == 'unhealthy':
            return False
        time.sleep(0.5)
    return False


info = start_with_healthcheck('registry.example/app:2.4', 'app-blue', 8080)
print('started:', info)

if wait_healthy('app-blue'):
    print('traffic can be routed to app-blue now')
else:
    logs = client.containers.get('app-blue').logs(tail=40).decode()
    print('unhealthy, last logs:')
    print(logs[-600:])