listen-fd-detached-inherit.js

var http = require('http');
var net = require('net');
if (process.argv[2] === 'child') child();
else parent();

function child() {
  // start a server on fd=3
  http.createServer(function(req, res) {
    console.error('request on child');
    console.error('%s %s', req.method, req.url, req.headers);
    res.end('hello from child\n');
  }).listen({ fd: 3 }, function() {
    console.error('child listening on fd=3');
  });
}

function parent() {
  var server = net.createServer(function(conn) {
    console.error('connection on parent');
    conn.end('hello from parent\n');
  }).listen(8000, function() {
    console.error('server listening on 8000', server._handle);

    var spawn = require('child_process').spawn;
    var child = spawn(process.execPath, [__filename, 'child'], {
      stdio: [ 0, 1, 2, server._handle ],
      detached: true
    });

    console.error('child pid = %d', child.pid);

    // Now close the parent, so that the child is the only thing
    // referencing that handle.  Note that connections will still
    // be accepted, because the child has the fd open, but the parent
    // will exit gracefully.
    server.close();
    child.unref();
  });
}

listen-fd-detached.js

var http = require('http');
var net = require('net');
if (process.argv[2] === 'child') child();
else parent();

function child() {
  // start a server on fd=3
  http.createServer(function(req, res) {
    console.error('request on child');
    console.error('%s %s', req.method, req.url, req.headers);
    res.end('hello from child\n');
  }).listen({ fd: 3 }, function() {
    console.error('child listening on fd=3');
  });
}

function parent() {
  var server = net.createServer(function(conn) {
    console.error('connection on parent');
    conn.end('hello from parent\n');
  }).listen(8000, function() {
    console.error('server listening on 8000', server._handle);

    var spawn = require('child_process').spawn;
    var child = spawn(process.execPath, [__filename, 'child'], {
      stdio: [ 'ignore', 'ignore', 'ignore', server._handle ],
      detached: true
    });

    console.error('child pid = %d', child.pid);

    // Now close the parent, so that the child is the only thing
    // referencing that handle.  Note that connections will still
    // be accepted, because the child has the fd open, but the parent
    // will exit gracefully.
    server.close();
    child.unref();
  });
}

listen-fd-server.js

var http = require('http');
var net = require('net');
if (process.argv[2] === 'child') child();
else parent();

function child() {
  // start a server on fd=3
  http.createServer(function(req, res) {
    console.error('request on child');
    console.error('%s %s', req.method, req.url, req.headers);
    res.end('hello from child\n');
  }).listen({ fd: 3 }, function() {
    console.error('child listening on fd=3');
  });
}

function parent() {
  var server = net.createServer(function(conn) {
    console.error('connection on parent');
    conn.end('hello from parent\n');
  }).listen(8000, function() {
    console.error('server listening on 8000', server._handle);

    var spawn = require('child_process').spawn;
    var child = spawn(process.execPath, [__filename, 'child'], {
      stdio: [ 0, 1, 2, server._handle ]
    });

    child.on('exit', function(code) {
      console.error('child exited', code);
    });

    child.on('close', function() {
      console.error('child closed');
    });
    console.error('child spawned');
  });
}