Remove implicit network in KafkaContainer (#2932)

Author: bsideup

modules/kafka/src/main/java/org/testcontainers/containers/KafkaContainer.java

@@ -29,16 +29,13 @@ public class KafkaContainer extends GenericContainer<KafkaContainer> {
 
     private int port = PORT_NOT_ASSIGNED;
 
-    private boolean useImplicitNetwork = true;
-
     public KafkaContainer() {
         this("5.2.1");
     }
 
     public KafkaContainer(String confluentPlatformVersion) {
         super(TestcontainersConfiguration.getInstance().getKafkaImage() + ":" + confluentPlatformVersion);
 
-        super.withNetwork(Network.SHARED);
         withExposedPorts(KAFKA_PORT);
 
         // Use two listeners with different names, it will force Kafka to communicate with itself via internal
@@ -54,26 +51,6 @@ public KafkaContainer(String confluentPlatformVersion) {
         withEnv("KAFKA_GROUP_INITIAL_REBALANCE_DELAY_MS", "0");
     }
 
-    @Override
-    public KafkaContainer withNetwork(Network network) {
-        useImplicitNetwork = false;
-        return super.withNetwork(network);
-    }
-
-    @Override
-    public Network getNetwork() {
-        if (useImplicitNetwork) {
-            // TODO Only for backward compatibility, to be removed soon
-            logger().warn(
-                "Deprecation warning! " +
-                    "KafkaContainer#getNetwork without an explicitly set network. " +
-                    "Consider using KafkaContainer#withNetwork",
-                new Exception("Deprecated method")
-            );
-        }
-        return super.getNetwork();
-    }
-
     public KafkaContainer withEmbeddedZookeeper() {
         externalZookeeperConnect = null;
         return self();

modules/kafka/src/test/java/org/testcontainers/containers/KafkaContainerTest.java

@@ -31,28 +31,6 @@ public void testUsage() throws Exception {
         }
     }
 
-    /**
-     * @deprecated the {@link Network} should be set explicitly with {@link KafkaContainer#withNetwork(Network)}.
-     */
-    @Test
-    @Deprecated
-    public void testExternalZookeeperWithKafkaNetwork() throws Exception {
-        try (
-            KafkaContainer kafka = new KafkaContainer()
-                .withExternalZookeeper("zookeeper:2181");
-
-            GenericContainer zookeeper = new GenericContainer("confluentinc/cp-zookeeper:4.0.0")
-                .withNetwork(kafka.getNetwork())
-                .withNetworkAliases("zookeeper")
-                .withEnv("ZOOKEEPER_CLIENT_PORT", "2181");
-        ) {
-            zookeeper.start();
-            kafka.start();
-
-            testKafkaFunctionality(kafka.getBootstrapServers());
-        }
-    }
-
     @Test
     public void testExternalZookeeperWithExternalNetwork() throws Exception {
         try (