Merge pull request #30951 from jacobwdv/JD_fix_kerb_container

adding the ability to check if a ports available before selecting a remote docker client

Author: jacobwdv

dev/com.ibm.ws.security.spnego_fat/override/autoFVT/src/ant/launch-overrides.xml

@@ -0,0 +1,12 @@
+<!--
+    Copyright (c) 2025 IBM Corporation and others.
+    All rights reserved. This program and the accompanying materials
+    are made available under the terms of the Eclipse Public License 2.0
+    which accompanies this distribution, and is available at
+    http://www.eclipse.org/legal/epl-2.0/
+
+    SPDX-License-Identifier: EPL-2.0
+ -->
+<project>
+    <property name="fat.test.docker.host.port" value="88"/>
+</project>

dev/com.ibm.ws.security.wim.adapter.ldap_fat.krb5.1/override/autoFVT/src/ant/launch-overrides.xml

@@ -0,0 +1,12 @@
+<!--
+    Copyright (c) 2025 IBM Corporation and others.
+    All rights reserved. This program and the accompanying materials
+    are made available under the terms of the Eclipse Public License 2.0
+    which accompanies this distribution, and is available at
+    http://www.eclipse.org/legal/epl-2.0/
+
+    SPDX-License-Identifier: EPL-2.0
+ -->
+<project>
+    <property name="fat.test.docker.host.port" value="88"/>
+</project>

dev/fattest.simplicity/src/componenttest/containers/ExternalDockerClientFilter.java

@@ -11,6 +11,8 @@
 
 import java.io.File;
 import java.io.IOException;
+import java.net.InetSocketAddress;
+import java.net.Socket;
 import java.nio.file.Files;
 
 import javax.net.SocketFactory;
@@ -38,6 +40,7 @@ public class ExternalDockerClientFilter implements ExternalTestServiceFilter {
      * Helpful when a developer wants to have repeatable behavior, or is remotely connected to a specific docker host.
      */
     private static final String FORCE_DOCKER_HOST = System.getProperty("fat.test.docker.host");
+    private static final String CHECK_PORT_AVAILABLE = System.getProperty("fat.test.docker.host.port");
 
     private boolean valid;
     private String host;
@@ -61,6 +64,14 @@ public boolean isForced() {
         return FORCE_DOCKER_HOST != null;
     }
 
+    public boolean checkPortAvailability() {
+        try {
+            return CHECK_PORT_AVAILABLE != null && Integer.valueOf(CHECK_PORT_AVAILABLE) >= 0;
+        } catch (NumberFormatException nfe) {
+            return false;
+        }
+    }
+
     /**
      * Determines if this docker host is healthy.
      *
@@ -79,6 +90,13 @@ public boolean isMatched(ExternalTestService dockerService) {
             return false;
         }
 
+        if (checkPortAvailability()) {
+            if (!isPortAvailable(dockerService.getAddress(), Integer.valueOf(CHECK_PORT_AVAILABLE))) {
+                Log.info(c, m, "Will not select " + dockerHostURL + " because port " + CHECK_PORT_AVAILABLE + " was not available.");
+                return false;
+            }
+        }
+
         String ca = dockerService.getProperties().get("ca.pem");
         String cert = dockerService.getProperties().get("cert.pem");
         String key = dockerService.getProperties().get("key.pem");
@@ -92,6 +110,7 @@ public boolean isMatched(ExternalTestService dockerService) {
 
         File certDir = new File("docker-certificates");
         certDir.mkdirs();
+
         writeFile(new File(certDir, "ca.pem"), ca);
         writeFile(new File(certDir, "cert.pem"), cert);
         writeFile(new File(certDir, "key.pem"), key);
@@ -121,6 +140,32 @@ public boolean isMatched(ExternalTestService dockerService) {
         return valid = true;
     }
 
+    /**
+     * isPortAvailable() is used to determine if the docker service has a specific host port available.
+     * This is used as filter criteria for tests that need a specific host port available.
+     *
+     * @param  host The host name or address to check
+     * @param  port The port on the host to test
+     * @return      True if the host does not accept a socket connection on the given port, false otherwise.
+     */
+    private boolean isPortAvailable(String host, int port) {
+        String prefix = "tcp://";
+        if (host.startsWith(prefix)) {
+            host = host.substring(prefix.length());
+        }
+
+        try (Socket socket = new Socket()) {
+            socket.connect(new InetSocketAddress(host, port), 5000);
+            return false;
+        } catch (IOException ex) {
+            // An exception here means the host wasn't listening on the port specified. This means the port should be available
+            // for the client to attach once it's started.
+            Log.info(c, "isPortAvailable", "Port " + port + " is available on host " + host);
+        }
+        return true;
+
+    }
+
     /**
      * Fail fast here! Never repeat this test!
      *