Add a lookup option to allow users to implement their own DNS resolution

README.md

@@ -134,6 +134,7 @@ __Arguments__
   * forceSNI - force use of [SNI](https://en.wikipedia.org/wiki/Server_Name_Indication) by the client. Allow node-http-mitm-proxy to handle all HTTPS requests with a single internal server.
   * httpsPort - The port or named socket for https server to listen on. _(forceSNI must be enabled)_
   * forceChunkedRequest - Setting this option will remove the content-length from the proxy to server request, forcing chunked encoding.
+  * lookup - The DNS lookup function to use. This option can be used to avoid the default synchronous DNS resolution. See [#314](https://github.com/joeferner/node-http-mitm-proxy/issues/314) for details.
 
 __Example__
 

lib/proxy.ts

@@ -1150,6 +1150,7 @@ export class Proxy implements IProxy {
         port: hostPort.port,
         headers,
         agent: ctx.isSSL ? self.httpsAgent : self.httpAgent,
+        lookup: this.options.lookup,
       };
       return self._onRequest(ctx, (err) => {
         if (err) {

lib/types.ts

@@ -4,6 +4,7 @@ import type CA from "../lib/ca";
 import type WebSocket from "ws";
 import type { Server } from "https";
 import type { WebSocket as WebSocketType, WebSocketServer } from "ws";
+import type { LookupFunction } from 'net';
 
 export interface IProxyStatic {
   (): IProxy;
@@ -34,6 +35,8 @@ export interface IProxyOptions {
   httpsPort?: number;
   /** - Setting this option will remove the content-length from the proxy to server request, forcing chunked encoding */
   forceChunkedRequest?: boolean;
+  /** - The DNS lookup function to use. This option can be used to avoid the default synchronous DNS resolution. See #314 for details. */
+  lookup?: LookupFunction;
 }
 
 export interface IProxySSLServer {
@@ -306,6 +309,7 @@ export type IContext = ICallbacks &
       port: string | number | null | undefined;
       headers: { [key: string]: string };
       agent: http.Agent;
+      lookup: LookupFunction | undefined;
     };
 
     onRequestHandlers: OnRequestParams[];