test (jkube-kit/remote-dev) : Fix intermittent failures of RemoteDeve…

…lopmentServiceTest

Signed-off-by: Rohan Kumar <rohaan@redhat.com>

jkube-kit/remote-dev/src/main/java/org/eclipse/jkube/kit/remotedev/RemoteDevelopmentService.java

@@ -16,6 +16,7 @@
 import io.fabric8.kubernetes.client.KubernetesClient;
 import org.eclipse.jkube.kit.common.KitLogger;
 
+import java.net.InetAddress;
 import java.net.ServerSocket;
 import java.util.concurrent.CompletableFuture;
 
@@ -65,7 +66,7 @@ public void stop() {
 
   private void checkEnvironment() {
     for (RemoteService remoteService : context.getRemoteDevelopmentConfig().getRemoteServices()) {
-      try (ServerSocket ignore = new ServerSocket(remoteService.getLocalPort())) {
+      try (ServerSocket ignore = new ServerSocket(remoteService.getLocalPort(), 50, InetAddress.getLoopbackAddress())) {
         logger.debug("Local port '%s' for remote service '%s:%s' is available",
           remoteService.getLocalPort(), remoteService.getHostname(), remoteService.getPort());
       } catch (Exception e) {

jkube-kit/remote-dev/src/test/java/org/eclipse/jkube/kit/remotedev/RemoteDevelopmentServiceTest.java

@@ -23,9 +23,15 @@
 import org.junit.jupiter.api.DisplayName;
 import org.junit.jupiter.api.Test;
 
+import java.io.IOException;
+import java.net.BindException;
+import java.net.InetAddress;
 import java.net.ServerSocket;
+import java.net.Socket;
 
+import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
 import static org.mockito.Mockito.spy;
 import static org.mockito.Mockito.timeout;
 import static org.mockito.Mockito.times;
@@ -109,20 +115,47 @@ void startInitsIfLocalPortAvailable() {
       .debug("Creating or replacing Kubernetes services for exposed ports from local environment");
   }
 
+  @Test
+  void nestedServerSocketsShouldThrowError() throws IOException {
+    try (ServerSocket ss1 = new ServerSocket(0, 50, InetAddress.getLoopbackAddress())) {
+      int port = ss1.getLocalPort();
+      assertThatExceptionOfType(BindException.class)
+          .isThrownBy(() -> {
+            try (ServerSocket ss2 = new ServerSocket(port, 50, InetAddress.getLoopbackAddress())) {
+              // Should be unreachable
+              assertThat(ss2.getLocalPort()).isEqualTo(port);
+            }
+          }).withMessageContaining("already in use");
+    }
+  }
+
   @Test
   @DisplayName("start fails if LocalPort for remote service is in use")
-  void startFailsIfLocalPortInUse() {
+  void startFailsIfLocalPortInUse() throws IOException {
     final int localPort = IoUtil.getFreeRandomPort();
     RemoteService remoteService = RemoteService.builder()
       .hostname("remote-host").localPort(localPort).port(1234).build();
     remoteDevelopmentService = new RemoteDevelopmentService(
       logger, kubernetesClient, RemoteDevelopmentConfig.builder().remoteService(remoteService).build());
-    assertThatThrownBy(() -> {
-      try (ServerSocket localPortInUse = new ServerSocket(localPort)) {
+
+      try (ServerSocket localPortInUse = new ServerSocket(localPort, 1, InetAddress.getLoopbackAddress())) {
         // When
-        remoteDevelopmentService.start();
+        assertThat(localPortInUse.getInetAddress().getHostAddress()).isEqualTo("127.0.0.1");
+        assertThat(localPortInUse.getLocalPort()).isEqualTo(localPort);
+        assertThat(localPortInUse.isBound()).isTrue();
+        assertThat(localPortInUse.isClosed()).isFalse();
+        try (Socket socket = new Socket("localhost", localPort)) {
+          assertThat(socket.getInetAddress().getHostAddress()).isEqualTo("127.0.0.1");
+          assertThat(socket.getPort()).isEqualTo(localPort);
+          assertThat(socket.isBound()).isTrue();
+          assertThat(socket.isClosed()).isFalse();
+          try (ServerSocket ss2 = new ServerSocket(remoteService.getLocalPort(), 1, InetAddress.getByName("localhost"))) {
+            assertThatThrownBy(() -> {
+              remoteDevelopmentService.start();
+            }).hasMessageContaining("Local port '" + localPort + "' is already in use (remote-host)");
+          }
+        }
       }
-    })
-      .hasMessageContaining("Local port '" + localPort + "' is already in use (remote-host)");
+
   }
 }