Convert Docs for Kafka Module #1158 (#2925)

Author: raynigon

docs/modules/kafka.md

@@ -11,41 +11,45 @@ More precisely Testcontainers uses the official Docker images for [Confluent OSS
 ## Example
 
 The following field in your JUnit test class will prepare a container running Kafka:
-```java
-@Rule
-public KafkaContainer kafka = new KafkaContainer();
-```
+<!--codeinclude-->
+[JUnit Rule](../../modules/kafka/src/test/java/org/testcontainers/containers/KafkaContainerTest.java) inside_block:junitRule
+<!--/codeinclude-->
         
 Now your tests or any other process running on your machine can get access to running Kafka broker by using the following bootstrap server location:
-```java
-kafka.getBootstrapServers()
-```
+
+<!--codeinclude-->
+[Bootstrap Servers](../../modules/kafka/src/test/java/org/testcontainers/containers/KafkaContainerTest.java) inside_block:getBootstrapServers
+<!--/codeinclude-->
+
 
 ## Options
 
 ### Selecting Kafka version
 
 You can select a version of Confluent Platform by passing it to the container's constructor:
-```java
-new KafkaContainer("4.1.2")
-```
+<!--codeinclude-->
+[Version Constructor](../../modules/kafka/src/test/java/org/testcontainers/containers/KafkaContainerTest.java) inside_block:constructorWithVersion
+<!--/codeinclude-->
+
+
 The correspondence between Confluent Platform versions and Kafka versions can be seen [in Confluent documentation](https://docs.confluent.io/current/installation/versions-interoperability.html#cp-and-apache-kafka-compatibility)
 
 ### <a name="zookeeper"></a> Using external Zookeeper
 
 If for some reason you want to use an externally running Zookeeper, then just pass its location during construction:
-```java
-new KafkaContainer().withExternalZookeeper("localhost:2181")
-```
+<!--codeinclude-->
+[External Zookeeper](../../modules/kafka/src/test/java/org/testcontainers/containers/KafkaContainerTest.java) inside_block:withExternalZookeeper
+<!--/codeinclude-->
+
 
 ## Multi-container usage
 
 If your test needs to run some other Docker container which needs access to the Kafka, do the following:
 
 * Run your other container on the same network as Kafka container, e.g.:
-```java
-new GenericContainer("myImage").withNetwork(kafka.getNetwork())
-```
+<!--codeinclude-->
+[Network](../../modules/kafka/src/test/java/org/testcontainers/containers/KafkaContainerTest.java) inside_block:withKafkaNetwork
+<!--/codeinclude-->
 * Use `kafka.getNetworkAliases().get(0)+":9092"` as bootstrap server location. 
 Or just give your Kafka container a network alias of your liking.
 

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

@@ -10,6 +10,7 @@
 import org.apache.kafka.clients.producer.ProducerRecord;
 import org.apache.kafka.common.serialization.StringDeserializer;
 import org.apache.kafka.common.serialization.StringSerializer;
+import org.junit.Rule;
 import org.junit.Test;
 import org.rnorth.ducttape.unreliables.Unreliables;
 
@@ -23,6 +24,11 @@
 
 public class KafkaContainerTest {
 
+    // junitRule {
+    @Rule
+    public KafkaContainer kafka = new KafkaContainer();
+    // }
+
     @Test
     public void testUsage() throws Exception {
         try (KafkaContainer kafka = new KafkaContainer()) {
@@ -31,22 +37,48 @@ public void testUsage() throws Exception {
         }
     }
 
+
+    @Test
+    public void testUsageWithVersion() throws Exception {
+        try (
+            // constructorWithVersion {
+            KafkaContainer kafka = new KafkaContainer("4.1.2")
+            // }
+        ) {
+            kafka.start();
+            testKafkaFunctionality(
+              // getBootstrapServers {
+              kafka.getBootstrapServers()
+              // }
+            );
+        }
+    }
+
     @Test
     public void testExternalZookeeperWithExternalNetwork() throws Exception {
         try (
             Network network = Network.newNetwork();
 
+            // withExternalZookeeper {
             KafkaContainer kafka = new KafkaContainer()
                 .withNetwork(network)
                 .withExternalZookeeper("zookeeper:2181");
+            // }
 
             GenericContainer zookeeper = new GenericContainer("confluentinc/cp-zookeeper:4.0.0")
                 .withNetwork(network)
                 .withNetworkAliases("zookeeper")
                 .withEnv("ZOOKEEPER_CLIENT_PORT", "2181");
+
+            // withKafkaNetwork {
+            GenericContainer application = new GenericContainer("alpine").withNetwork(kafka.getNetwork())
+            // }
+                .withNetworkAliases("dummy")
+                .withCommand("sleep 10000")
         ) {
             zookeeper.start();
             kafka.start();
+            application.start();
 
             testKafkaFunctionality(kafka.getBootstrapServers());
         }