heartbeat-by-request

const axios = require('axios');
const fork = require("child_process").fork;
var server, heartbeat;
const time = 20000;

function startServer() {
  console.log(new Date() + " :: starting server");
  server = fork("./server.js");

  server.on("close", code => {
    console.log(new Date() + " :: restart server");
    startServer();
  });

  setTimeout(checkHeartbeat, time);
}

function checkHeartbeat() {
  const port = process.env.PORT || 3000;
  axios.get(`http://localhost:${port}`,{
    validateStatus: function (status) {
      return status <= 500;
    }
  })
  .then(function (response) {
    setTimeout(checkHeartbeat, time);
  })
  .catch(function (error) {
    console.log(new Date() + " :: server looks stuck, killing now");
    server.kill();
  })
}

startServer();