How to Mock a Slow Startup Probe in Python

import time
from dataclasses import dataclass, field


@dataclass
class StartupProbe:
    name: str
    min_wait_sec: float = 0.5
    max_wait_sec: float = 2.0
    _ready: bool = field(default=False, init=False, repr=False)

    def initialize(self) -> None:
        """Simulate slow startup with a fixed mock delay."""
        delay = self.min_wait_sec + (self.max_wait_sec - self.min_wait_sec) / 2
        print(f"[{self.name}] Initializing... (mock delay {delay:.2f}s)")
        time.sleep(delay)
        self._ready = True
        print(f"[{self.name}] Ready.")

    @property
    def ready(self) -> bool:
        return self._ready


def probe(service: StartupProbe) -> bool:
    """Return readiness status after initialization."""
    if not service.ready:
        service.initialize()
    return service.ready


if __name__ == "__main__":
    db = StartupProbe("database", min_wait_sec=0.2, max_wait_sec=1.0)
    api = StartupProbe("api", min_wait_sec=0.5, max_wait_sec=1.5)

    start = time.time()
    print(f"DB ready: {probe(db)}")
    print(f"API ready: {probe(api)}")
    print(f"Total elapsed: {time.time() - start:.2f}s")