gwrok keep-alive

keep-alive.js

const net = require('node:net');

function keepAlive(ephPort, intervalId) {
	const socket = new net.Socket();
	socket.setTimeout(1000);
	socket.connect(port, process.env.GWROK_IP, () => socket.destroy());
	// stop the interval, indicate either the gwrok server no longer accept request
	// or just bad internet connection and should retry if this is the case.
	// for now we not perform retry, just stop the interval.
	socket.on('timeout', () => {
		clearInterval(intervalId);
	});
}

const intervalId = setInterval(
	() => keepAlive(ephPort, intervalId),
	1000 * process.env.KEEPALIVE_TIMEOUT
);

keep-alive.sh

#!/bin/sh

# The script will prevent the gwrok client from closing the connection after 5 minutes of inactivity.
# usage:
# - start gwrok client first:
# setsid ./gwrok client <client parameter> &>/tmp/gwrok-http.log </dev/null
# - start the keep-alive:
# setsid ./keep-alive.sh <ip> <port> &>/tmp/gwrok-http.log </dev/null

while :;do printf 'GET / HTTP/1.1\r\nHost: $1\r\n\r\n' | nc $1 $2;sleep 4m;done

references:

• the clean version of >file 2&>1 - man bash and locate the &> string.
• setting keep-alive in both side, apache and telnet - serverfault
• run script as daemon, supress stdin, stderr, and stdout in order to completely detach process from the shell - stackoverflow
• nohup, setsid, disown % - stackoverflow, related to persisting running background program (daemon)
• superuser

for keep-alive ssh service: while :;do nc -d -N <ip> <port>;sleep 5;done

-d: disable stdin
-N: immediately exit after connect

moved to another repository