core/homeassistant/helpers/signal.py

"""Signal handling related helpers."""
import logging
import signal

from homeassistant.const import RESTART_EXIT_CODE
from homeassistant.core import HomeAssistant, callback
from homeassistant.loader import bind_hass

_LOGGER = logging.getLogger(__name__)


@callback
@bind_hass
def async_register_signal_handling(hass: HomeAssistant) -> None:
    """Register system signal handler for core."""

    @callback
    def async_signal_handle(exit_code: int) -> None:
        """Wrap signal handling.

        * queue call to shutdown task
        * re-instate default handler
        """
        hass.loop.remove_signal_handler(signal.SIGTERM)
        hass.loop.remove_signal_handler(signal.SIGINT)
        hass.async_create_task(hass.async_stop(exit_code))

    try:
        hass.loop.add_signal_handler(signal.SIGTERM, async_signal_handle, 0)
    except ValueError:
        _LOGGER.warning("Could not bind to SIGTERM")

    try:
        hass.loop.add_signal_handler(signal.SIGINT, async_signal_handle, 0)
    except ValueError:
        _LOGGER.warning("Could not bind to SIGINT")

    try:
        hass.loop.add_signal_handler(
            signal.SIGHUP, async_signal_handle, RESTART_EXIT_CODE
        )
    except ValueError:
        _LOGGER.warning("Could not bind to SIGHUP")