wait-for-camera-server

#!/usr/bin/env python3

import argparse
from datetime import datetime, timedelta
import sys
import time
import urllib.request

CONN_TIMEOUT = 5


def is_api_server_up(host, port):
    try:
        r = urllib.request.urlopen(
            "http://{}:{}/".format(host, port), timeout=CONN_TIMEOUT
        )
    except:
        return False
    return r.getcode() == 200


def main():
    parser = argparse.ArgumentParser(description="Wait for camera server to be running")
    parser.add_argument(
        "--port", default=2040, type=int, help="Port to check for the fake camera server"
    )
    parser.add_argument(
        "-w",
        "--wait-mins",
        default=5,
        type=int,
        help="Minutes to wait for the camera server",
    )
    args = parser.parse_args()

    print("waiting up to {} minutes for camera server...".format(args.wait_mins))
    max_time = datetime.now() + timedelta(minutes=args.wait_mins)
    while datetime.now() < max_time:
        if is_api_server_up("localhost", args.port):
            print("camera server is running")
            return 0
        time.sleep(3)

    print("fake thermal camera server failed to start")
    return 1


if __name__ == "__main__":
    sys.exit(main())