Avoid setting container config on doStart method

src/main/java/io/strimzi/test/container/StrimziKafkaContainer.java

@@ -18,7 +18,6 @@
 
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -87,6 +86,12 @@ public StrimziKafkaContainer(String dockerImageName) {
     private StrimziKafkaContainer(CompletableFuture<String> imageName) {
         super(imageName);
         this.imageNameProvider = imageName;
+        // we need this shared network in case we deploy StrimziKafkaCluster which consist of `StrimziKafkaContainer`
+        // instances and by default each container has its own network, which results in `Unable to resolve address: zookeeper:2181`
+        super.setNetwork(Network.SHARED);
+        // exposing kafka port from the container
+        super.setExposedPorts(Collections.singletonList(KAFKA_PORT));
+        super.addEnv("LOG_DIR", "/tmp");
     }
 
     @Override
@@ -103,16 +108,10 @@ protected void doStart() {
             throw new RuntimeException(e);
         }
         // exposing Kafka and port from the container
-        if (this.hasKraftOrExternalZooKeeperConfigured()) {
-            super.setExposedPorts(Collections.singletonList(KAFKA_PORT));
-        } else {
+        if (!this.hasKraftOrExternalZooKeeperConfigured()) {
             // expose internal ZooKeeper internal port iff external ZooKeeper or KRaft is not specified/enabled
-            super.setExposedPorts(Arrays.asList(KAFKA_PORT, StrimziZookeeperContainer.ZOOKEEPER_PORT));
+            super.addExposedPort(StrimziZookeeperContainer.ZOOKEEPER_PORT);
         }
-        // we need this shared network in case we deploy StrimziKafkaCluster which consist of `StrimziKafkaContainer`
-        // instances and by default each container has its own network, which results in `Unable to resolve address: zookeeper:2181`
-        super.setNetwork(Network.SHARED);
-        super.addEnv("LOG_DIR", "/tmp");
         // we need it for the startZookeeper(); and startKafka(); to run container before...
         super.setCommand("sh", "-c", runStarterScript());
         super.doStart();

src/main/java/io/strimzi/test/container/StrimziZookeeperContainer.java

@@ -63,13 +63,6 @@ public StrimziZookeeperContainer(String dockerImageName) {
     private StrimziZookeeperContainer(CompletableFuture<String> imageName) {
         super(imageName);
         this.imageNameProvider = imageName;
-    }
-
-    @Override
-    protected void doStart() {
-        if (!imageNameProvider.isDone()) {
-            imageNameProvider.complete(KafkaVersionService.strimziTestContainerImageName(kafkaVersion));
-        }
         // we need this shared network in case we deploy StrimziKafkaCluster, which consist `StrimziZookeeperContainer`
         // instance and by default each container has its own network
         super.setNetwork(Network.SHARED);
@@ -80,6 +73,13 @@ protected void doStart() {
         super.addEnv("ZOOKEEPER_CLIENT_PORT", String.valueOf(ZOOKEEPER_PORT));
         // env for readiness
         super.addEnv("ZOO_4LW_COMMANDS_WHITELIST", "ruok");
+    }
+
+    @Override
+    protected void doStart() {
+        if (!imageNameProvider.isDone()) {
+            imageNameProvider.complete(KafkaVersionService.strimziTestContainerImageName(kafkaVersion));
+        }
         // we need it for the startZookeeper(); and startKafka(); to run container before...
         withCommand("sh", "-c", "while [ ! -f " + STARTER_SCRIPT + " ]; do sleep 0.1; done; " + STARTER_SCRIPT);
         super.doStart();

src/test/java/io/strimzi/test/container/StrimziKafkaContainerIT.java

@@ -11,6 +11,7 @@
 import org.hamcrest.CoreMatchers;
 import org.junit.jupiter.api.Test;
 import org.testcontainers.containers.Container;
+import org.testcontainers.containers.Network;
 import org.testcontainers.utility.MountableFile;
 
 import java.io.IOException;
@@ -171,6 +172,25 @@ void testStartContainerWithCustomImage() {
         systemUnderTest.stop();
     }
 
+    @Test
+    void testStartContainerWithCustomNetwork() {
+        assumeDocker();
+
+        Network network = Network.newNetwork();
+
+        systemUnderTest = new StrimziKafkaContainer()
+                .withNetwork(network)
+                .waitForRunning();
+
+        systemUnderTest.start();
+
+        assertThat(systemUnderTest.getBootstrapServers(), is("PLAINTEXT://"
+                + systemUnderTest.getContainerIpAddress() + ":" + systemUnderTest.getMappedPort(9092)));
+
+        assertThat(systemUnderTest.getNetwork().getId(), is(network.getId()));
+        systemUnderTest.stop();
+    }
+
     @Test
     void testUnsupportedKafkaVersion() {
         assumeDocker();