Add debugging feature which leaves integration test containers runnin…

…g after test completes

- For debugging purposes, it is useful to have the ability to leave containers running.
  This mode can be activated by setting environment variable TESTCONTAINERS_RYUK_DISABLED=true

- TESTCONTAINERS_RYUK_DISABLED=true also disables TestContainers automatic container
  cleanup, https://www.testcontainers.org/features/configuration/#disabling-ryuk .
  - in this case, use this command afterwards to kill docker containers started
    by Testcontainers:
    docker ps -q --filter "label=org.testcontainers=true" | xargs -r docker kill

tests/integration/src/test/java/org/apache/pulsar/tests/integration/containers/PulsarContainer.java

@@ -48,6 +48,15 @@ public abstract class PulsarContainer<SelfT extends PulsarContainer<SelfT>> exte
     public static final String PULSAR_2_1_IMAGE_NAME = "apachepulsar/pulsar:2.1.0";
     public static final String PULSAR_2_0_IMAGE_NAME = "apachepulsar/pulsar:2.0.0";
 
+    /**
+     * For debugging purposes, it is useful to have the ability to leave containers running.
+     * This mode can be activated by setting environment variable TESTCONTAINERS_RYUK_DISABLED=true
+     * After debugging, one can use this command to kill containers started by Testcontainers:
+     * docker ps -q --filter "label=org.testcontainers=true" | xargs -r docker kill
+     */
+    public static final boolean LEAVE_CONTAINERS_RUNNING =
+            Boolean.parseBoolean(System.getenv("TESTCONTAINERS_RYUK_DISABLED"));
+
     private final String hostname;
     private final String serviceName;
     private final String serviceEntryPoint;
@@ -109,6 +118,15 @@ protected void beforeStop() {
         }
     }
 
+    @Override
+    public void stop() {
+        if (LEAVE_CONTAINERS_RUNNING) {
+            log.warn("Ignoring stop since TESTCONTAINERS_RYUK_DISABLED=true.");
+            return;
+        }
+        super.stop();
+    }
+
     @Override
     public String getContainerName() {
         return clusterName + "-" + hostname;

tests/integration/src/test/java/org/apache/pulsar/tests/integration/topologies/PulsarCluster.java

@@ -21,6 +21,7 @@
 import static com.google.common.base.Preconditions.checkArgument;
 import static org.apache.pulsar.tests.integration.containers.PulsarContainer.BROKER_HTTP_PORT;
 import static org.apache.pulsar.tests.integration.containers.PulsarContainer.CS_PORT;
+import static org.apache.pulsar.tests.integration.containers.PulsarContainer.LEAVE_CONTAINERS_RUNNING;
 import static org.apache.pulsar.tests.integration.containers.PulsarContainer.ZK_PORT;
 
 import com.google.common.collect.Lists;
@@ -309,6 +310,10 @@ public PrestoWorkerContainer getPrestoWorkerContainer() {
     }
 
     public synchronized void stop() {
+        if (LEAVE_CONTAINERS_RUNNING) {
+            log.warn("Ignoring stop since TESTCONTAINERS_RYUK_DISABLED=true.");
+            return;
+        }
 
         List<GenericContainer> containers = new ArrayList<>();