test(e2e): Use an external host address for the Lambda DSN on loopback hostnames

The AWS serverless E2E apps point the Lambda's DSN at the host IP that
the runner's hostname resolves to. On Namespace runners the hostname
resolves to 127.0.0.1, which inside the Lambda container is the container
itself, so no event reached the event proxy and every test timed out.

When the hostname resolves to a loopback address, use the first external
IPv4 address that is not a Docker bridge.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: JPeer264

dev-packages/e2e-tests/test-applications/aws-serverless-layer/src/stack.ts

@@ -118,14 +118,31 @@ export class LocalLambdaStack extends Stack {
 
 export async function getHostIp() {
   if (process.env.GITHUB_ACTIONS) {
-    const host = await dns.lookup(os.hostname());
-    return host.address;
+    return getExternalHostIp();
   }
 
   if (platform === 'darwin' || platform === 'win32') {
     return 'host.docker.internal';
   }
 
+  return getExternalHostIp();
+}
+
+/**
+ * The Lambda container reaches the event proxy on the host through an address of the host's network interface.
+ * Some runners (e.g. Namespace) map the hostname to a loopback address, which inside the container is the container
+ * itself, so fall back to the first external IPv4 address that is not a Docker bridge.
+ */
+async function getExternalHostIp(): Promise<string> {
   const host = await dns.lookup(os.hostname());
-  return host.address;
+  if (!host.address.startsWith('127.') && host.address !== '::1') {
+    return host.address;
+  }
+
+  const external = Object.entries(os.networkInterfaces())
+    .filter(([name]) => !name.startsWith('docker') && !name.startsWith('br-') && !name.startsWith('veth'))
+    .flatMap(([, addresses]) => addresses ?? [])
+    .find(address => address.family === 'IPv4' && !address.internal);
+
+  return external?.address ?? host.address;
 }

dev-packages/e2e-tests/test-applications/aws-serverless/src/stack.ts

@@ -159,14 +159,31 @@ export class LocalLambdaStack extends Stack {
 
 export async function getHostIp() {
   if (process.env.GITHUB_ACTIONS) {
-    const host = await dns.lookup(os.hostname());
-    return host.address;
+    return getExternalHostIp();
   }
 
   if (platform === 'darwin' || platform === 'win32') {
     return 'host.docker.internal';
   }
 
+  return getExternalHostIp();
+}
+
+/**
+ * The Lambda container reaches the event proxy on the host through an address of the host's network interface.
+ * Some runners (e.g. Namespace) map the hostname to a loopback address, which inside the container is the container
+ * itself, so fall back to the first external IPv4 address that is not a Docker bridge.
+ */
+async function getExternalHostIp(): Promise<string> {
   const host = await dns.lookup(os.hostname());
-  return host.address;
+  if (!host.address.startsWith('127.') && host.address !== '::1') {
+    return host.address;
+  }
+
+  const external = Object.entries(os.networkInterfaces())
+    .filter(([name]) => !name.startsWith('docker') && !name.startsWith('br-') && !name.startsWith('veth'))
+    .flatMap(([, addresses]) => addresses ?? [])
+    .find(address => address.family === 'IPv4' && !address.internal);
+
+  return external?.address ?? host.address;
 }