Example of Node.js forking and maintaining debug port for worker.

app.js

var path = require('path');
var child_process = require('child_process');
var currentFork;

var timesStarted = 0;

function fork(){
  var args = process.argv.slice(2),
      execArgs = process.execArgv,
      isDebug = process.execArgv.indexOf('--debug');

  // rudimentary example of making sure we bind to a different
  // debug port than the master process
  if (isDebug > -1) {
    execArgs.splice(isDebug, 1);
    execArgs.push('--debug=5859');
  }

  // fork this file with args + '--worker' and sameish execArgs
  currentFork = child_process.fork(__filename, args);

  timesStarted++;

  currentFork.on('close', fork);
}

setInterval(function failsafe() {
  if (timesStarted > 1) {
    console.error("loop detected");
    currentFork.kill();
    process.exit(0);
  }
  timesStarted = 0;
}, 500);


// fork if this is the master
// process will not have .send if it isn't a fork
if (!process.send) {
  fork();
  // cycle fork simulation
  setInterval(function() {
    currentFork.kill();
  }, 3000);
}


/*

results:

┌[josh@jarvice] [130]
└[~/code/clustertest]> node --debug app.js
Debugger listening on port 5858      -- this is the master
Debugger listening on port 5859      -- fork
Debugger listening on port 5859      -- ^^
Debugger listening on port 5859
Debugger listening on port 5859

*/