support for skipping requests to some hosts

allows skipping local requests or any other requests by hostname

Author: alexsorokoletov

src/__tests__/proxy_server.spec.js

@@ -148,7 +148,7 @@ describe('proxy_server', () => {
 
   describe('requestListener', () => {
     it('should create an socks agent and take it as request agent', () => {
-      requestListener(getProxyInfo, request, response);
+      requestListener([], getProxyInfo, request, response);
 
       const lastCall = last(Socks.Agent.mock.calls);
       const httpLastCall = last(http.request.mock.calls);
@@ -158,7 +158,7 @@ describe('proxy_server', () => {
     });
 
     it('should return 500 when error thrown', () => {
-      requestListener(getProxyInfo, request, response);
+      requestListener([], getProxyInfo, request, response);
 
       const onErrorArgs = getLastMockOn('error');
 
@@ -179,7 +179,7 @@ describe('proxy_server', () => {
         pipe: jest.fn(),
       };
 
-      requestListener(getProxyInfo, request, response);
+      requestListener([], getProxyInfo, request, response);
 
       const onResponseArgs = getLastMockOn('response');
 

src/cli.js

@@ -10,6 +10,7 @@ const optionNames = [
   'level',
   'config',
   'host',
+  'skip',
 ];
 
 function getFileConfig(filePath) {
@@ -51,6 +52,7 @@ function main() {
     .option('-p, --port [port]', 'specify the listening port of http proxy server, default: 8080')
     .option('-l, --host [host]', 'specify the listening host of http proxy server, default: 127.0.0.1')
     .option('-c, --config [config]', 'read configs from file in json format')
+    .option('--skip [hostname1|hostname2]', 'skip proxy for hostname1 and hostname2 and so on')
     .option('--level [level]', 'log level, vals: info, error')
     .parse(process.argv);
 

src/proxy_server.js

@@ -29,25 +29,28 @@ function parseProxyLine(line) {
   return getProxyObject.apply(this, proxyInfo);
 }
 
-function requestListener(getProxyInfo, request, response) {
+function requestListener(hostnamesToSkip, getProxyInfo, request, response) {
   logger.info(`request: ${request.url}`);
-
   const proxy = getProxyInfo();
   const ph = url.parse(request.url);
-
-  const socksAgent = new Socks.Agent({
-    proxy,
-    target: { host: ph.hostname, port: ph.port },
-  });
+  const shouldProxy = !hostnamesToSkip
+                        || (hostnamesToSkip.indexOf(ph.hostname.toLowerCase()) === -1);
 
   const options = {
     port: ph.port,
     hostname: ph.hostname,
     method: request.method,
     path: ph.path,
     headers: request.headers,
-    agent: socksAgent,
   };
+  if (shouldProxy) {
+    options.agent = new Socks.Agent({
+      proxy,
+      target: { host: ph.hostname, port: ph.port },
+    });
+  } else {
+    logger.info('skipping this request because it is local');
+  }
 
   const proxyRequest = http.request(options);
 
@@ -120,8 +123,8 @@ function connectListener(getProxyInfo, request, socketRequest, head) {
 
 function ProxyServer(options) {
   // TODO: start point
-  http.Server.call(this, () => {});
-
+  http.Server.call(this, () => { });
+  this.hostnamesToSkip = (options.skip || '').split('|');
   this.proxyList = [];
 
   if (options.socks) {
@@ -142,7 +145,7 @@ function ProxyServer(options) {
 
   this.addListener(
     'request',
-    requestListener.bind(null, () => randomElement(this.proxyList))
+    requestListener.bind(null, this.hostnamesToSkip, () => randomElement(this.proxyList))
   );
   this.addListener(
     'connect',

src/server.js

@@ -6,6 +6,7 @@ const DEFAULT_OPTIONS = {
   socks: '127.0.0.1:1080',
   proxyListReloadTimeout: 60,
   port: 8080,
+  skip: 'localhost|127.0.0.1'
 };
 
 function createServer(opts) {
@@ -15,10 +16,10 @@ function createServer(opts) {
     changeLevel(logger, options.level);
   }
 
-  const { port, socks, host } = options;
+  const { port, socks, host, skip } = options;
 
   // eslint-disable-next-line
-  console.log(`SOCKS: ${socks}\nhttp-proxy listening: ${host}:${port}`);
+  console.log(`SOCKS: ${socks}\nhttp-proxy listening: ${host}:${port}, skiplist: ${skip}`);
 
   return createProxyServer(options).listen(port, host);
 }