main.py

from threading import Event
import signal

from click import command, option
from loguru import logger
from prometheus_client import start_http_server
from prometheus_client.core import REGISTRY
from yaml import safe_load

from collector import Collector


def graceful_shutdown(shutdown_event):
    def _handle(sig, frame):
        logger.warning("caught signal for shutdown, stopping service.", extra={
            "signal": sig,
        })

        shutdown_event.set()
    
    signal.signal(signal.SIGINT, _handle)


def start_monitoring(prometheus_port, collector):
    start_http_server(prometheus_port)
    REGISTRY.register(collector)


@command()
@option(
    '--tapo-email', envvar="TAPO_USER_EMAIL",
    help="Email address associated with Meross account."
)
@option(
    '--tapo-password', envvar="TAPO_USER_PASSWORD",
    help="Password associated with TP-Link TAPO account."
)
@option(
    '--config-file', default="tapo.yaml", envvar="TAPO_MONITOR_CONFIG",
    help="Password associated with TP-Link TAPO account."
)
@option(
    '--prometheus-port', default=8080, help="port for prometheus metric exposition"
)
def run(tapo_email, tapo_password, config_file, prometheus_port):
    with open(config_file, "r") as cfg:
        config = safe_load(cfg)
    
    logger.info("configuring metrics collector and prometheus http server")
    collector = Collector(config['devices'], tapo_email, tapo_password)
    start_monitoring(prometheus_port, collector)

    shutdown = Event()
    graceful_shutdown(shutdown)

    logger.info("service is up, and awaiting for signals to stop")
    shutdown.wait()


if __name__ == "__main__":
    run()