From b78d353c7a1965d73f006a1c2361afb99f2cbe31 Mon Sep 17 00:00:00 2001
From: Colum Ferry <cferry09@gmail.com>
Date: Fri, 29 Apr 2022 13:49:53 +0100
Subject: [PATCH] fix(angular): cleanup ports on exit of mf server (#10060)

---
 .../module-federation-dev-server.impl.ts      | 59 ++++++++++++++++++-
 1 file changed, 58 insertions(+), 1 deletion(-)

diff --git a/packages/angular/src/builders/module-federation-dev-server/module-federation-dev-server.impl.ts b/packages/angular/src/builders/module-federation-dev-server/module-federation-dev-server.impl.ts
index b697cc520cafa..5c34633feb665 100644
--- a/packages/angular/src/builders/module-federation-dev-server/module-federation-dev-server.impl.ts
+++ b/packages/angular/src/builders/module-federation-dev-server/module-federation-dev-server.impl.ts
@@ -5,6 +5,51 @@ import { BuilderContext, createBuilder } from '@angular-devkit/architect';
 import { JsonObject } from '@angular-devkit/core';
 import { join } from 'path';
 import { webpackServer } from '../webpack-server/webpack-server.impl';
+import { exec, execSync } from 'child_process';
+
+/**
+ * Inline kill-port to prevent adding a new dependency
+ */
+function killPort(port, method = 'tcp') {
+  port = Number.parseInt(port);
+
+  if (!port) {
+    throw new Error('Invalid argument provided for port');
+  }
+
+  if (process.platform === 'win32') {
+    return exec('netstat -nao', (error, stdout, stderr) => {
+      if (!stdout) return;
+
+      const lines = stdout.split('\n');
+      // The second white-space delimited column of netstat output is the local port,
+      // which is the only port we care about.
+      // The regex here will match only the local port column of the output
+      const lineWithLocalPortRegEx = new RegExp(
+        `^ *${method.toUpperCase()} *[^ ]*:${port}`,
+        'gm'
+      );
+      const linesWithLocalPort = lines.filter((line) =>
+        line.match(lineWithLocalPortRegEx)
+      );
+
+      const pids = linesWithLocalPort.reduce((acc, line) => {
+        const match = line.match(/(\d*)\w*(\n|$)/gm);
+        return match && match[0] && !acc.includes(match[0])
+          ? acc.concat(match[0])
+          : acc;
+      }, []);
+
+      return execSync(`TaskKill /F /PID ${pids.join(' /PID ')}`);
+    });
+  }
+
+  return execSync(
+    `lsof -ni ${method === 'udp' ? 'udp' : 'tcp'}:${port} | grep ${
+      method === 'udp' ? 'UDP' : 'LISTEN'
+    } | awk '{print $2}' | xargs kill -9`
+  );
+}
 
 export function moduleFederationDevServer(
   schema: Schema,
@@ -40,13 +85,20 @@ export function moduleFederationDevServer(
     ? options.devRemotes
     : [options.devRemotes];
 
+  const remotePorts: number[] = [];
   for (const remote of remotes) {
     const isDev = devServeRemotes.includes(remote);
+    const target = isDev ? 'serve' : 'serve-static';
+
+    remotePorts.push(
+      workspaceConfig.projects[remote]?.targets[target]?.options.port ?? 4200
+    );
+
     scheduleTarget(
       context.workspaceRoot,
       {
         project: remote,
-        target: isDev ? 'serve' : 'serve-static',
+        target,
         configuration: context.target.configuration,
         runOptions: {},
         executor: context.builder.builderName,
@@ -55,6 +107,11 @@ export function moduleFederationDevServer(
     );
   }
 
+  // Cleanup ports on kill
+  process.on('kill', () => {
+    remotePorts.forEach((port) => killPort(port));
+  });
+
   return webpackServer(options, context);
 }