app.js

"use strict";

var conf = require("node-conf"),
    http = require("http"),
    https = require("https"),
    fs = require("fs"),
    path = require("path"),
    express = require("express"),
    cluster = require("cluster"),
    Logging = require("./lib/logging"),
    Filters = require("./lib/filters"),
    Middlewares = require("./lib/middlewares"),
    Datastore = require("./lib/datastore"),
    Boomerang = require("./lib/boomerang");

var numCpus = require("os").cpus().length;
var config = conf.load(process.env.NODE_ENV);
var app;

if ( typeof config.server === "undefined" ) {
  var error = new Error("Error could not parse configuration!");
  console.error(error);
  process.exit(1);
}

var logging = new Logging(config.log);
var filters = new Filters(config.filter, logging.filterLogger);

function handleError(exception) {
  logging.datastoreLogger.fatal( { error: exception }, exception);
  process.exit();
}

function main(dsInstance) {
  var boomerang = new Boomerang(config, dsInstance, filters, logging.appLogger);
  app = express();
  app.use(boomerang.router());
  app.use(logging.webLogger);
  app.use(new Middlewares(config));
  config.server.listeners.forEach(startListener);
}

function postStartup() {
  if (typeof config.security !== "undefined") {
    logging.appLogger.info({context: config.security}, "Dropping to security context " + (config.security.user || "boomerang") + ":" + (config.security.group || "boomerang"));
    process.setgid(config.security.group || "boomerang");
    process.setuid(config.security.user || "boomerang");
  } else {
    logging.appLogger.info({context: { user: "boomerang", group: "boomerang" }}, "Dropping to security context boomerang:boomerang");
    process.setgid("boomerang");
    process.setuid("boomerang");
  }
}

function startListener(listener) {
  if (listener.protocol === "http" ) {
    logging.appLogger.info({ listener: listener }, "Starting HTTP Application Server");
    httpListener(listener);
  } else if (listener.protocol === "https" ) {
    logging.appLogger.info({ listener: listener }, "Starting HTTPS Application Server");
    httpsListener(listener);
  }
}

function httpListener(listener) {
  var server = http.createServer(app);
  server.listen(listener.port, listener.listen, postStartup);
}

function httpsListener(listener) {
  var server = https.createServer({
    key: fs.readFileSync(path.resolve(listener.key)),
    cert: fs.readFileSync(path.resolve(listener.cert))
  }, app);

  server.listen(listener.port, listener.listen, postStartup);
}

if (cluster.isMaster) {

  var forks = 0;
  if (config.server.threads) {
    if (config.server.threads > numCpus) {
      forks = numCpus;
    } else {
      forks = config.server.threads;
    }
  } else {
    forks = 1;
  }


  for (var i = 0; i < forks; i++) {
    cluster.fork();
  }
} else {

  var ds = new Datastore(config.datastore, logging.datastoreLogger);
  if (ds.init(config.datastore.active)) {
    main(ds);
  } else {
    handleError(new Error("Could not initialize the Datastore"));
  }
}