Basic process monitor

monitor.js

const { spawn } = require("child_process");

const COMMAND = "ls"
const ALLOWED_REBOOTS = 10

async function main() {
  console.log("Starting process");
  let counter = 0;
  let failed = false;
  let handle;

  start();

  async function start() {
    handle = spawn(COMMAND);
    handle.stdout.on("data", (data) => {
      console.log(data.toString("utf-8"));
    });

    handle.stderr.on("data", (data) => {
      console.error(data.toString("utf-8"));
    });

    handle.on("close", (exitCode) => {
      console.log(`Process exited with code ${exitCode}, restarting...`);
      failed = true;
      counter = counter + 1;
      if (counter > ALLOWED_REBOOTS)
        return console.log(
          "Bailing after " + ALLOWED_REBOOTS + " restarts at " + new Date().toISOString()
        );
      start();
    });
  }
}

main();