index.js

// Copyright (c) 2018 ExcitableAardvark <excitableaardvark@tutanota.de>
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice,
//    this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution.
//
// 3. Neither the name of the copyright holder nor the names of its contributors
//    may be used to endorse or promote products derived from this software
//    without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.

const NOTIFY_SOCKET = process.env.NOTIFY_SOCKET
const WATCHDOG_USEC = process.env.WATCHDOG_USEC

const native = require('bindings')('systemd_notify2')
const watchdogInterval = WATCHDOG_USEC ? (WATCHDOG_USEC / 1000) : 0

const notify = NOTIFY_SOCKET ? native.notify : () => {}
const ready = NOTIFY_SOCKET ? () => notify('READY=1') : () => {}
const setupWatchdog = (NOTIFY_SOCKET && watchdogInterval !== 0) ?
	() => setInterval(() => notify('WATCHDOG=1'), watchdogInterval) :
	() => {}

module.exports = {
	notify,
	ready,
	setupWatchdog
}