springer-uptime/lib/pollers/https/httpsPoller.js

Remote monitoring for HTTP applications

/**
 * Module dependencies.
 */

var util  = require('util');
var http  = require('http');
var requestlib = require('request');
var url   = require('url');
var fs    = require('fs');
var ejs   = require('ejs');
var BaseHttpPoller = require('../http/baseHttpPoller');

// The http module lacks proxy support. Let's monkey-patch it.
require('../../proxy');

/**
 * HTTPS Poller, to check web pages served via SSL
 *
 * @param {Mixed} Poller Target (e.g. URL)
 * @param {Number} Poller timeout in milliseconds. Without response before this duration, the poller stops and executes the error callback.
 * @param {Function} Error/success callback
 * @api   public
 */
function HttpsPoller(target, timeout, callback) {
  HttpsPoller.super_.call(this, target, timeout, callback);
}

util.inherits(HttpsPoller, BaseHttpPoller);

HttpsPoller.type = 'https';

HttpsPoller.validateTarget = function(target) {
  return url.parse(target).protocol == 'https:';
};

/**
 * Launch the actual polling
 *
 * @api   public
 */
HttpsPoller.prototype.poll = function(secure) {
  HttpsPoller.super_.prototype.poll.call(this);
  try {
    this.request = requestlib.get(this.target.href).on('response', this.onResponseCallback.bind(this));
  } catch(err) {
    return this.onErrorCallback(err);
  }
  this.request.on('error', this.onErrorCallback.bind(this));
};

// see inherited function BaseHttpPoller.prototype.onResponseCallback
// see inherited function BaseHttpPoller.prototype.onErrorCallback

HttpsPoller.prototype.handleRedirectResponse = function(res) {
  this.debug(this.getTime() + "ms - Got redirect response to " + this.target.href);
  var target = url.parse(res.headers.location);
  if (!target.protocol) {
    // relative location header. This is incorrect but tolerated
    this.target = url.parse('http://' + this.target.hostname + res.headers.location);
    this.poll(false);
    return;
  }
  switch (target.protocol) {
    case 'https:':
      this.target = target;
      this.poll(true);
      break;
    case 'http:':
      this.target = target;
      this.poll(false);
      break;
    default:
      this.request.abort();
      this.onErrorCallback({ name: "WrongRedirectUrl", message: "Received redirection from https: to unsupported protocol " + target.protocol});
  }
  return;
};

module.exports = HttpsPoller;