Find free port in the host sample

microsoft · Nov 6, 2024 · db98e48 · db98e48
1 parent e4f416b
commit db98e48
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Showing 2 changed files with 73 additions and 37 deletions.
diff --git a/samples/ts/client/index.ts b/samples/ts/client/index.ts
@@ -102,7 +102,7 @@ async function main() {
 
     console.log("\nStopping tunnel client..."); 
     client.dispose();
-    
+
   } catch (err) {
     console.error(err);
   }

diff --git a/samples/ts/host/index.ts b/samples/ts/host/index.ts
@@ -10,41 +10,67 @@ import {
   TunnelAccessScopes,
   TunnelEndpoint,
 } from "@microsoft/dev-tunnels-contracts";
-import {
-  TunnelRelayTunnelHost,
-} from "@microsoft/dev-tunnels-connections";
-import * as http from 'http';
+import { TunnelRelayTunnelHost } from "@microsoft/dev-tunnels-connections";
+import * as http from "http";
+import net from "net";
 
-const portNumber = 8080;
+let portNumber = 8090;
 const protocol = "http";
 
-function startServer(): Promise<http.Server> {
+function findFreePort(startPort: number): Promise<number> {
+  return new Promise((resolve, reject) => {
+    const server = net.createServer();
+    server.once("error", (err: NodeJS.ErrnoException) => {
+      if (err.code === "EADDRINUSE") {
+        findFreePort(startPort + 1)
+          .then(resolve)
+          .catch(reject);
+      } else {
+        reject(err);
+      }
+    });
+    server.once("listening", () => server.close(() => resolve(startPort)));
+    server.listen(startPort);
+  });
+};
+
+async function startServer(): Promise<http.Server> {
+  portNumber = await findFreePort(portNumber);
+
   const server = http.createServer((req, res) => {
     res.statusCode = 200;
-    res.setHeader('Content-Type', 'text/plain');
-    res.end('Hello, world!\n');
+    res.setHeader("Content-Type", "text/plain");
+    res.end("Hello, world!\n");
   });
-  
-  return new Promise((resolve) => {
-    server.listen(portNumber, () => {
+
+  await new Promise<void>((resolve) => {
+    server.listen({ port: portNumber, exclusive: true }, () => {
       console.log(`Server running at ${protocol}://localhost:${portNumber}/`);
-      resolve(server);
-    })
-  });;
+      resolve();
+    });
+  });
+
+  return server;
 }
 
-async function createTunnelAndConnectHost(tunnelManagementClient: TunnelManagementHttpClient) {
+async function createTunnelAndConnectHost(
+  tunnelManagementClient: TunnelManagementHttpClient
+) {
   const newTunnel: Tunnel = {
-    ports: [{ 
-      portNumber, 
-      protocol,
-    }],
+    ports: [
+      {
+        portNumber,
+        protocol,
+      },
+    ],
     accessControl: {
-      entries: [{
-        type: TunnelAccessControlEntryType.Anonymous,
-        subjects: [],
-        scopes: [TunnelAccessScopes.Connect],
-      }],
+      entries: [
+        {
+          type: TunnelAccessControlEntryType.Anonymous,
+          subjects: [],
+          scopes: [TunnelAccessScopes.Connect],
+        },
+      ],
     },
   };
 
@@ -65,21 +91,28 @@ async function createTunnelAndConnectHost(tunnelManagementClient: TunnelManageme
 
   await host.connect(tunnel!);
 
-  console.log('Tunnel host connected:');
+  console.log("Tunnel host connected:");
   console.log(`    Tunnel ID: ${tunnel.tunnelId}`);
   console.log(`    Cluster ID: ${tunnel.clusterId}`);
   const clientAccessToken = tunnel.accessTokens?.[TunnelAccessScopes.Connect];
   if (clientAccessToken) {
     console.log(`    Client access token: ${clientAccessToken}`);
   }
 
-  tunnel.ports?.forEach(({portNumber, portForwardingUris}) => {
+  tunnel.ports?.forEach(({ portNumber, portForwardingUris }) => {
     console.log(`    Tunnel port: ${portNumber}`);
     if (portForwardingUris) {
-      portForwardingUris.forEach((uri) => console.log(`        Port forwarding URI: ${uri}`));
+      portForwardingUris.forEach((uri) =>
+        console.log(`        Port forwarding URI: ${uri}`)
+      );
     } else {
       newTunnel.endpoints?.forEach((endpoint) => {
-        console.log(`        Port forwarding URI: ${TunnelEndpoint.getPortUri(endpoint, portNumber)}`);
+        console.log(
+          `        Port forwarding URI: ${TunnelEndpoint.getPortUri(
+            endpoint,
+            portNumber
+          )}`
+        );
       });
     }
   });
@@ -101,13 +134,15 @@ function readAnyKey() {
       }
 
       resolve();
-      });  
+    });
   });
 }
 
 const aadToken = process.env.AAD_TOKEN;
 if (!aadToken) {
-  console.error("AAD_TOKEN environment variable is required. You can get your AAD token by running 'devtunnels login --verbose' and copying the token from the output.");
+  console.error(
+    "AAD_TOKEN environment variable is required. You can get your AAD token by running 'devtunnels login --verbose' and copying the token from the output."
+  );
   process.exit(1);
 }
 
@@ -125,7 +160,7 @@ function createTunnelManagementClient() {
 
   tunnelManagementClient.trace = (msg) => {
     console.log(`tunnel: ${msg}`);
-  }
+  };
 
   return tunnelManagementClient;
 }
@@ -135,24 +170,25 @@ async function main() {
     const server = await startServer();
 
     const tunnelManagementClient = createTunnelManagementClient();
-  
+
     console.log("\nCreating tunnel and starting host...");
-    const { tunnel, host } = await createTunnelAndConnectHost(tunnelManagementClient);
+    const { tunnel, host } = await createTunnelAndConnectHost(
+      tunnelManagementClient
+    );
     console.log("\nPress any key to exit...\n");
     await readAnyKey();
 
-    console.log("\nStopping tunnel host..."); 
+    console.log("\nStopping tunnel host...");
     host.dispose();
     server.close();
 
     console.log("\nDeleting tunnel...");
     await tunnelManagementClient.deleteTunnel(tunnel);
-
   } catch (err) {
     console.error(err);
   }
 
   process.exit();
 }
 
-main();
+main();