How to Mock a Liveness Check and Restart a Process in Python

import subprocess
import sys
import time
import os

class ProcessMock:
    def __init__(self, name, fail_after_seconds=3):
        self.name = name
        self.fail_after = fail_after_seconds
        self.start_time = None
        self.is_running = False

    def start(self):
        self.start_time = time.time()
        self.is_running = True
        print(f"[{self.name}] started")

    def is_alive(self):
        if not self.is_running:
            return False
        return time.time() - self.start_time < self.fail_after

    def stop(self):
        self.is_running = False
        print(f"[{self.name}] stopped")

    def restart(self):
        print(f"[{self.name}] restarting...")
        self.stop()
        self.start()

def run_liveness_loop(process, check_interval=1.0):
    attempts = 0
    max_attempts = 3
    while attempts < max_attempts:
        time.sleep(check_interval)
        if process.is_alive():
            print(f"[{process.name}] healthy")
        else:
            print(f"[{process.name}] FAILED liveness check")
            process.restart()
            attempts += 1
    print(f"[{process.name}] giving up after {max_attempts} restart attempts")

if __name__ == "__main__":
    process = ProcessMock(name="worker", fail_after_seconds=2)
    process.start()
    run_liveness_loop(process)