move mitmproxy launching into separate file

TODO incorporate
ably · Jul 18, 2024 · ac51627 · ac51627
1 parent cce0442
commit ac51627
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Showing 2 changed files with 93 additions and 78 deletions.
diff --git a/test/interception-proxy/InterceptionContext.ts b/test/interception-proxy/InterceptionContext.ts
@@ -1,4 +1,3 @@
-import { ChildProcessWithoutNullStreams, spawn } from 'child_process';
 import {
   ClientMethods,
   createTransformInterceptedMessageParamsDTO,
@@ -19,6 +18,7 @@ import { ProxyMessage } from './Proxy';
 import { ProxyServer } from './ProxyServer';
 import { webSocketMessageDataLoggingDescription } from './WebSocketMessageData';
 import { TypedJSONRPCServerAndClient, JSONRPCClient, JSONRPCServer, JSONRPCServerAndClient } from 'json-rpc-2.0';
+import { MitmproxyLauncher } from './MitmproxyLauncher';
 
 type ServerParams = {
   controlServerConnection: ControlServerConnection;
@@ -29,7 +29,7 @@ export class InterceptionContext {
   proxyServer: ProxyServer | null = null;
   private jsonRPC: TypedJSONRPCServerAndClient<ServerMethods, ClientMethods, ServerParams>;
   private interceptedMessagesQueue = new InterceptedMessagesQueue();
-  private onMitmproxyReady: (() => void) | null = null;
+  private mitmproxyLauncher: MitmproxyLauncher | null = null;
 
   constructor() {
     this.jsonRPC = new JSONRPCServerAndClient(
@@ -42,7 +42,7 @@ export class InterceptionContext {
     this.jsonRPC.addMethod('startInterception', (params, serverParams) =>
       this.startInterception(params, serverParams.controlServerConnection),
     );
-    this.jsonRPC.addMethod('mitmproxyReady', () => this.onMitmproxyReady?.());
+    this.jsonRPC.addMethod('mitmproxyReady', () => this.mitmproxyLauncher?.onMitmproxyReady());
   }
 
   onControlWebSocketMessage(data: string, controlServerConnection: ControlServerConnection) {
@@ -52,81 +52,9 @@ export class InterceptionContext {
 
   async startInterception(params: InterceptionModeDTO, controlServerConnection: ControlServerConnection): Promise<{}> {
     this.controlServer!.setActiveConnection(controlServerConnection);
-
-    console.log('starting mitmdump, mode', params.mode);
-
-    let mitmdumpBinary: string;
-    let mitmdumpMode: string | null;
-
-    // TODO this is currently written on the assumption that darwin means running locally and linux means running in GitHub action; sort out so that you can run (locally or on CI) on (macOS or Linux)
-    switch (process.platform) {
-      case 'darwin':
-        mitmdumpBinary = 'mitmdump';
-        switch (params.mode) {
-          case 'local':
-            mitmdumpMode = `local:${params.pid}`;
-            break;
-          case 'proxy':
-            mitmdumpMode = null;
-            break;
-        }
-        break;
-      case 'linux':
-        // Currently we expect that you set up the iptables rules externally
-        mitmdumpBinary = '/opt/pipx_bin/mitmdump';
-        switch (params.mode) {
-          case 'local':
-            mitmdumpMode = 'transparent';
-            break;
-          case 'proxy':
-            mitmdumpMode = null;
-            break;
-        }
-        break;
-      default:
-        throw new Error(`Don’t know how to set up mitmdump interception for platform ${process.platform}`);
-    }
-
-    // sounds like we don’t need to explicitly stop this when we stop the current process: https://nodejs.org/api/child_process.html#optionsdetached
-    const mitmdump = spawn(mitmdumpBinary, [
-      '--set',
-      'stream_large_bodies=1',
-      ...(mitmdumpMode === null ? [] : ['--mode', mitmdumpMode]),
-      '-s',
-      'test/mitmproxy_addon_2.py',
-      '--set',
-      // "full request URL with response status code and HTTP headers" (the default truncates the URL)
-      'flow_detail=2',
-    ]);
-
-    const formatMitmdumpOutput = (source: string, data: Buffer) => {
-      const text = data.toString('utf-8');
-      const lines = text.split('\n');
-      return lines.map((line) => `mitmdump ${source}: ${line}`).join('\n');
-    };
-
-    mitmdump.stdout.on('data', (data) => {
-      console.log(formatMitmdumpOutput('stdout', data));
-    });
-
-    mitmdump.stderr.on('data', (data) => {
-      console.log(formatMitmdumpOutput('stderr', data));
-    });
-
-    console.log(`Waiting for mitmdump to start`);
-
-    let resolveResult: () => void;
-    const result = new Promise<{}>((resolve) => {
-      resolveResult = () => resolve({});
-    });
-
-    this.onMitmproxyReady = () => {
-      this.onMitmproxyReady = null;
-      console.log(`mitmdump has started`);
-      resolveResult();
-    };
-
-    return result;
+    this.mitmproxyLauncher = new MitmproxyLauncher();
+    await this.mitmproxyLauncher.launch(params);
+    return {};
   }
 
   private handleTransformInterceptedMessageResponse(

diff --git a/test/interception-proxy/MitmproxyLauncher.ts b/test/interception-proxy/MitmproxyLauncher.ts
@@ -0,0 +1,87 @@
+import { spawn } from 'child_process';
+import { InterceptionModeDTO } from './ControlRPC';
+
+export class MitmproxyLauncher {
+  private _onMitmproxyReady: (() => void) | null = null;
+
+  async launch(mode: InterceptionModeDTO) {
+    console.log('starting mitmdump, mode', mode);
+
+    let mitmdumpBinary: string;
+    let mitmdumpMode: string | null;
+
+    // TODO this is currently written on the assumption that darwin means running locally and linux means running in GitHub action; sort out so that you can run (locally or on CI) on (macOS or Linux)
+    switch (process.platform) {
+      case 'darwin':
+        mitmdumpBinary = 'mitmdump';
+        switch (mode.mode) {
+          case 'local':
+            mitmdumpMode = `local:${mode.pid}`;
+            break;
+          case 'proxy':
+            mitmdumpMode = null;
+            break;
+        }
+        break;
+      case 'linux':
+        // Currently we expect that you set up the iptables rules externally
+        mitmdumpBinary = '/opt/pipx_bin/mitmdump';
+        switch (mode.mode) {
+          case 'local':
+            mitmdumpMode = 'transparent';
+            break;
+          case 'proxy':
+            mitmdumpMode = null;
+            break;
+        }
+        break;
+      default:
+        throw new Error(`Don’t know how to set up mitmdump interception for platform ${process.platform}`);
+    }
+
+    // sounds like we don’t need to explicitly stop this when we stop the current process: https://nodejs.org/api/child_process.html#optionsdetached
+    const mitmdump = spawn(mitmdumpBinary, [
+      '--set',
+      'stream_large_bodies=1',
+      ...(mitmdumpMode === null ? [] : ['--mode', mitmdumpMode]),
+      '-s',
+      'test/mitmproxy_addon_2.py',
+      '--set',
+      // "full request URL with response status code and HTTP headers" (the default truncates the URL)
+      'flow_detail=2',
+    ]);
+
+    const formatMitmdumpOutput = (source: string, data: Buffer) => {
+      const text = data.toString('utf-8');
+      const lines = text.split('\n');
+      return lines.map((line) => `mitmdump ${source}: ${line}`).join('\n');
+    };
+
+    mitmdump.stdout.on('data', (data) => {
+      console.log(formatMitmdumpOutput('stdout', data));
+    });
+
+    mitmdump.stderr.on('data', (data) => {
+      console.log(formatMitmdumpOutput('stderr', data));
+    });
+
+    console.log(`Waiting for mitmdump to start`);
+
+    let resolveResult: () => void;
+    const result = new Promise<{}>((resolve) => {
+      resolveResult = () => resolve({});
+    });
+
+    this._onMitmproxyReady = () => {
+      this._onMitmproxyReady = null;
+      console.log(`mitmdump has started`);
+      resolveResult();
+    };
+
+    return result;
+  }
+
+  onMitmproxyReady() {
+    this._onMitmproxyReady?.();
+  }
+}