feat: add optional proxy hook configuration

FireBlinkLTD · Nov 17, 2023 · 21bab59 · 21bab59
1 parent c351814
commit 21bab59
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Showing 7 changed files with 86 additions and 9 deletions.
diff --git a/README.md b/README.md
@@ -21,6 +21,7 @@ yarn add prxi
 
 ```typescript
 import { Prxi, HttpMethod, ProxyRequest} from 'prxi';
+import { OutgoingHttpHeaders, RequestOptions, ServerResponse } from 'http';
 
 // Instantiate new Prxi, requires a src/Configuration.ts configuration object
 const proxy = new Prxi({
@@ -139,6 +140,25 @@ const requestHandlers = [
           'X-ADD_TO_RESPONSE': 'value',
           'X-REMOVE_FROM_RESPONSE': null,
         },
+
+        /**
+         * Optional handler before making the proxy request
+         * @param options request options
+         * @returns
+         */
+        onBeforeProxyRequest: (options: RequestOptions) => {
+
+        }
+
+        /**
+         * Optional handler before sending a response
+         * @param res
+         * @param outgoingHeaders
+         * @returns
+         */
+        onBeforeResponse: (res: ServerResponse, outgoingHeaders: OutgoingHttpHeaders) => {
+
+        }
       });
     }
   }
@@ -189,6 +209,15 @@ const webSocketHandlers = [
           'X-ADD_TO_RESPONSE': 'value',
           'X-REMOVE_FROM_RESPONSE': null,
         },
+
+        /**
+         * Optional handler before making the proxy request
+         * @param options request options
+         * @returns
+         */
+        onBeforeProxyRequest: (options: RequestOptions) => {
+
+        }
       );
 
       // alternatively cancel request with custom http status code and message

diff --git a/src/handlers/HttpProxyHandler.ts b/src/handlers/HttpProxyHandler.ts
@@ -1,6 +1,5 @@
-import { IncomingMessage, ServerResponse } from "node:http";
-import {request as httpRequest, RequestOptions} from 'node:http';
-import {request as httpsRequest} from 'node:https';
+import {request as httpRequest, RequestOptions, IncomingMessage, ServerResponse} from 'http';
+import {request as httpsRequest} from 'https';
 
 import { Configuration, ProxyRequestConfiguration } from "../interfaces";
 import { UpstreamConfiguration } from "../interfaces/UpstreamConfiguration";
@@ -62,6 +61,11 @@ export class HttpProxyHandler {
       timeout: this.configuration.proxyRequestTimeout,
     };
 
+    /* istanbul ignore else */
+    if (proxyConfiguration && proxyConfiguration.onBeforeProxyRequest) {
+      proxyConfiguration.onBeforeProxyRequest(options);
+    }
+
     const client = request(options);
 
     await new Promise<void>((resolve, reject) => {
@@ -86,6 +90,12 @@ export class HttpProxyHandler {
           // istanbul ignore next
           proxyConfiguration?.proxyResponseHeaders
         );
+
+        /* istanbul ignore else */
+        if (proxyConfiguration && proxyConfiguration.onBeforeResponse) {
+          proxyConfiguration.onBeforeResponse(res, headersToSet);
+        }
+
         RequestUtils.updateResponseHeaders(res, headersToSet);
 
         // istanbul ignore else

diff --git a/src/handlers/WebSocketProxyHandler.ts b/src/handlers/WebSocketProxyHandler.ts
@@ -42,7 +42,11 @@ export class WebSocketProxyHandler {
   ): Promise<void> {
     try {
       WebSocketProxyHandler.debug.incomingSocket = socket;
-      proxyConfiguration = proxyConfiguration || emptyObj;
+      /* istanbul ignore next */
+      if (!proxyConfiguration) {
+        proxyConfiguration = emptyObj;
+      }
+
 
       // istanbul ignore next
       let target = proxyConfiguration.target || this.upstream.target;
@@ -74,6 +78,11 @@ export class WebSocketProxyHandler {
         timeout: this.configuration.proxyRequestTimeout,
       };
 
+      /* istanbul ignore else */
+      if (proxyConfiguration && proxyConfiguration.onBeforeProxyRequest) {
+        proxyConfiguration.onBeforeProxyRequest(options);
+      }
+
       const client = request(options);
       WebSocketProxyHandler.debug.upstreamRequest = client;
 

diff --git a/src/interfaces/ProxyRequestConfiguration.ts b/src/interfaces/ProxyRequestConfiguration.ts
@@ -1,3 +1,4 @@
+import { OutgoingHttpHeaders, RequestOptions, ServerResponse } from 'http';
 import { HttpMethod } from './RequestHandler';
 
 export interface ProxyRequestConfiguration {
@@ -18,4 +19,19 @@ export interface ProxyRequestConfiguration {
 
   // Proxy response headers to add/replace/remove on top of the Configuration ones (if any)
   proxyResponseHeaders?: Record<string, string | string[] | null>;
+
+  /**
+   * Optional handler before making the proxy request
+   * @param options request options
+   * @returns
+   */
+  onBeforeProxyRequest?: (options: RequestOptions) => void;
+
+  /**
+   * Optional handler before sending a response
+   * @param res
+   * @param outgoingHeaders
+   * @returns
+   */
+  onBeforeResponse?: (res: ServerResponse, outgoingHeaders: OutgoingHttpHeaders) => void;
 }
diff --git a/src/utils/RequestUtils.ts b/src/utils/RequestUtils.ts
@@ -1,7 +1,5 @@
 import { OutgoingHttpHeaders, OutgoingMessage, IncomingMessage, IncomingHttpHeaders } from "http";
 
-const emptyObj = {};
-
 export class RequestUtils {
   /**
    * Extract path from the request

diff --git a/test/HttpProxy.success.suite.ts b/test/HttpProxy.success.suite.ts
@@ -131,6 +131,7 @@ export class HttpProxySuccessSuite {
       reqproxylevelclear: result.data.headers['reqproxylevelclear'],
       reqconfiglevel: result.data.headers['reqconfiglevel'],
       test: result.data.headers['test'],
+      ON_BEFORE_PROXY_HEADER: result.data.headers['ON_BEFORE_PROXY_HEADER'.toLowerCase()],
     }
 
     deepEqual(requestHeaders, {
@@ -139,6 +140,7 @@ export class HttpProxySuccessSuite {
       reqproxylevel: 'PROXY-REQUEST',
       reqproxylevelclear: undefined,
       test: 'true',
+      ON_BEFORE_PROXY_HEADER: 'yes',
     });
 
     const responseHeaders = {
@@ -147,6 +149,7 @@ export class HttpProxySuccessSuite {
       resproxylevel: result.headers['resproxylevel'],
       resproxylevelclear: result.headers['resproxylevelclear'],
       ['res-test']: result.headers['res-test'],
+      ON_BEFORE_RESPONSE_HEADER: result.headers['ON_BEFORE_RESPONSE_HEADER'.toLowerCase()],
     }
 
     deepEqual(responseHeaders, {
@@ -155,6 +158,7 @@ export class HttpProxySuccessSuite {
       resproxylevel: 'PROXY-RESPONSE',
       resproxylevelclear: undefined,
       ['res-test']: 'test-res',
+      ON_BEFORE_RESPONSE_HEADER: 'yes',
     });
   }
 

diff --git a/test/helpers/TestProxy.ts b/test/helpers/TestProxy.ts
@@ -1,7 +1,8 @@
 import { IncomingMessage, ServerResponse } from 'http';
 import { Duplex } from 'stream';
-import { ErrorHandler, Prxi, ProxyRequest, WebSocketHandlerFunction, WebSocketHandlerConfig, Configuration } from '../../src';
+import { ErrorHandler, Prxi, ProxyRequest, WebSocketHandlerFunction, WebSocketHandlerConfig, Configuration, ProxyRequestConfiguration } from '../../src';
 import { TestServer } from './TestServer';
+import { RequestOptions } from 'https';
 
 export class TestProxyParams {
   configOverride?: Partial<Configuration>;
@@ -107,6 +108,12 @@ export class TestProxy {
         RESConfigLevelOverwrite: 'PROXY-RESPONSE-OVERWRITE',
         RESProxyLevelClear: null,
       },
+      onBeforeProxyRequest: (options: RequestOptions) => {
+        options.headers['ON_BEFORE_PROXY_HEADER'] = 'yes';
+      },
+      onBeforeResponse: (res, outgoingHeaders) => {
+        outgoingHeaders['ON_BEFORE_RESPONSE_HEADER'] = 'yes';
+      }
     });
   }
 
@@ -117,8 +124,12 @@ export class TestProxy {
    * @param head
    * @param handle
    */
-  private async wsHandler(req: IncomingMessage, socket: Duplex, head: Buffer, handle: () => Promise<void>) {
-    await handle();
+  private async wsHandler(req: IncomingMessage, socket: Duplex, head: Buffer, handle: (configuration?: ProxyRequestConfiguration) => Promise<void>) {
+    await handle({
+      onBeforeProxyRequest: (options: RequestOptions) => {
+        options.headers['ON_BEFORE_WS_PROXY_HEADER'] = 'yes';
+      }
+    });
   }
 
   /**