From 954ee7a225ab5806d8ee98ca4243a7b312ede636 Mon Sep 17 00:00:00 2001
From: Neil Manvar <ndmanvar@yahoo.com>
Date: Fri, 17 Nov 2017 00:52:32 -0800
Subject: [PATCH] Add support for sending events through proxy

For both HTTP and HTTPS endpoints. Uses tunnel-agent for https.
---
 lib/transports.js | 64 +++++++++++++++++++++++++++++++++++++++++------
 package.json      |  1 +
 2 files changed, 58 insertions(+), 7 deletions(-)

diff --git a/lib/transports.js b/lib/transports.js
index a606a95..4097394 100644
--- a/lib/transports.js
+++ b/lib/transports.js
@@ -6,8 +6,12 @@ var timeoutReq = require('timed-out');
 
 var http = require('http');
 var https = require('https');
+var tunnel = require('tunnel-agent');
 
-var agentOptions = {keepAlive: true, maxSockets: 100};
+var agentOptions = {
+  keepAlive: true,
+  maxSockets: 100
+};
 var httpAgent = new http.Agent(agentOptions);
 var httpsAgent = new https.Agent(agentOptions);
 
@@ -21,7 +25,7 @@ function HTTPTransport(options) {
   this.agent = httpAgent;
 }
 util.inherits(HTTPTransport, Transport);
-HTTPTransport.prototype.send = function(client, message, headers, eventId, cb) {
+HTTPTransport.prototype.send = function (client, message, headers, eventId, cb) {
   var options = {
     hostname: client.dsn.host,
     path: client.dsn.path + 'api/' + client.dsn.project_id + '/store/',
@@ -31,6 +35,20 @@ HTTPTransport.prototype.send = function(client, message, headers, eventId, cb) {
     ca: client.ca,
     agent: this.agent
   };
+
+  // set path apprpriately when using http endpoint + proxy, set proxy headers appropriately when using https endpoint + proxy
+  if (this.options.hasOwnProperty('proxyHost')) {
+    if (client.dsn.protocol === 'http') {
+      options.path = 'http://' + client.dsn.host + ':' + client.dsn.port + client.dsn.path + 'api/' + client.dsn.project_id + '/store/';
+      delete options.hostname; // only 'host' should be set when using proxy
+    } else {
+      this.options.agent.proxyOptions.headers = {
+        'Content-Type': 'application/octet-stream',
+        host: client.dsn.host + ':' + client.dsn.port
+      }
+    }
+  }
+
   for (var key in this.options) {
     if (this.options.hasOwnProperty(key)) {
       options[key] = this.options[key];
@@ -38,7 +56,10 @@ HTTPTransport.prototype.send = function(client, message, headers, eventId, cb) {
   }
 
   // prevent off heap memory explosion
-  var _name = this.agent.getName({host: client.dsn.host, port: client.dsn.port});
+  var _name = this.agent.getName({
+    host: client.dsn.host,
+    port: client.dsn.port
+  });
   var _requests = this.agent.requests[_name];
   if (_requests && Object.keys(_requests).length > client.maxReqQueueCount) {
     // other feedback strategy
@@ -46,7 +67,7 @@ HTTPTransport.prototype.send = function(client, message, headers, eventId, cb) {
     return;
   }
 
-  var req = this.transport.request(options, function(res) {
+  var req = this.transport.request(options, function (res) {
     res.setEncoding('utf8');
     if (res.statusCode >= 200 && res.statusCode < 300) {
       client.emit('logged', eventId);
@@ -63,9 +84,8 @@ HTTPTransport.prototype.send = function(client, message, headers, eventId, cb) {
       client.emit('error', e);
       cb && cb(e);
     }
-
     // force the socket to drain
-    var noop = function() {};
+    var noop = function () {};
     res.on('data', noop);
     res.on('end', noop);
   });
@@ -73,7 +93,7 @@ HTTPTransport.prototype.send = function(client, message, headers, eventId, cb) {
   timeoutReq(req, client.sendTimeout * 1000);
 
   var cbFired = false;
-  req.on('error', function(e) {
+  req.on('error', function (e) {
     client.emit('error', e);
     if (!cbFired) {
       cb && cb(e);
@@ -89,10 +109,40 @@ function HTTPSTransport(options) {
   this.options = options || {};
   this.agent = httpsAgent;
 }
+
+function HTTPProxyTransport(options) {
+  this.defaultPort = 80;
+  this.transport = http;
+  this.options = options || {};
+  this.agent = httpAgent;
+  this.options.host = options.proxyHost;
+  this.options.port = options.proxyPort;
+}
+
+function HTTPSProxyTransport(options) {
+  this.transport = https;
+  this.options = options || {};
+  this.agent = httpsAgent;
+  this.options.agent = tunnel['httpsOverHttp']({
+    proxy: {
+      host: options.proxyHost,
+      port: options.proxyPort,
+      proxyAuth: null // TODO: Add ability to specify creds/auth
+    },
+    keepAlive: agentOptions.keepAlive,
+    maxSockets: agentOptions.maxSockets
+  });
+}
+
 util.inherits(HTTPSTransport, HTTPTransport);
+util.inherits(HTTPProxyTransport, HTTPTransport);
+util.inherits(HTTPSProxyTransport, HTTPTransport);
 
 module.exports.http = new HTTPTransport();
 module.exports.https = new HTTPSTransport();
 module.exports.Transport = Transport;
 module.exports.HTTPTransport = HTTPTransport;
 module.exports.HTTPSTransport = HTTPSTransport;
+
+module.exports.HTTPProxyTransport = HTTPProxyTransport;
+module.exports.HTTPSProxyTransport = HTTPSProxyTransport;
diff --git a/package.json b/package.json
index ebeec85..0899449 100644
--- a/package.json
+++ b/package.json
@@ -34,6 +34,7 @@
     "lsmod": "1.0.0",
     "stack-trace": "0.0.9",
     "timed-out": "4.0.1",
+    "tunnel-agent": "^0.6.0",
     "uuid": "3.0.0"
   },
   "devDependencies": {