def METHOD_NAME(docker: DockerClient, registry: str, howdy: str):
    tag_prefix = slugify(pendulum.now("utc").isoformat())[:20]
    registry_tag = push_image(howdy, registry, "prefecthq/howdy")
    assert registry_tag.startswith(f"localhost:5555/prefecthq/howdy:{tag_prefix}")
    greeting = docker.containers.run(registry_tag, remove=True).decode().strip()
    assert greeting.startswith("hello from the registry")