GH-1827: ContainerGroupSequencerTests Diagnostics

Set `autoStartup` to `false` so we see the `Starting first group` message.

**cherry-pick to 2.7.x**

Author: garyrussell

Diff for: spring-kafka/src/main/java/org/springframework/kafka/listener/ContainerGroupSequencer.java

@@ -64,6 +64,10 @@ public class ContainerGroupSequencer implements ApplicationContextAware,
 
 	private ContainerGroup currentGroup;
 
+	private boolean autoStartup = true;
+
+	private int phase = AbstractMessageListenerContainer.DEFAULT_PHASE;
+
 	private boolean running;
 
 	/**
@@ -98,6 +102,34 @@ public synchronized void setStopLastGroupWhenIdle(boolean stopLastGroupWhenIdle)
 		this.stopLastGroupWhenIdle = stopLastGroupWhenIdle;
 	}
 
+	@Override
+	public boolean isAutoStartup() {
+		return this.autoStartup;
+	}
+
+	/**
+	 * Set to false to not automatically start.
+	 * @param autoStartup false to not start;
+	 * @since 2.7.6
+	 */
+	public void setAutoStartup(boolean autoStartup) {
+		this.autoStartup = autoStartup;
+	}
+
+	@Override
+	public int getPhase() {
+		return this.phase;
+	}
+
+	/**
+	 * Set the {@link SmartLifecycle#getPhase()}.
+	 * @param phase the phase.
+	 * @since 2.7.6
+	 */
+	public void setPhase(int phase) {
+		this.phase = phase;
+	}
+
 	@Override
 	public synchronized void onApplicationEvent(ListenerContainerIdleEvent event) {
 		LOGGER.debug(() -> event.toString());
@@ -127,7 +159,7 @@ private void stopParentAndCheckGroup(MessageListenerContainer parent) {
 					if (this.currentGroup.allStopped()) {
 						if (this.iterator.hasNext()) {
 							this.currentGroup = this.iterator.next();
-							LOGGER.debug(() -> "starting next group: " + this.currentGroup);
+							LOGGER.debug(() -> "Starting next group: " + this.currentGroup);
 							this.currentGroup.start();
 						}
 						else {
@@ -142,7 +174,7 @@ private void stopParentAndCheckGroup(MessageListenerContainer parent) {
 	@Override
 	public synchronized void start() {
 		if (this.currentGroup != null) {
-			LOGGER.debug(() -> "starting first group: " + this.currentGroup);
+			LOGGER.debug(() -> "Starting first group: " + this.currentGroup);
 			this.currentGroup.start();
 		}
 		this.running = true;

Diff for: spring-kafka/src/test/java/org/springframework/kafka/listener/ContainerGroupSequencerTests.java

@@ -43,6 +43,7 @@
 import org.springframework.kafka.core.ProducerFactory;
 import org.springframework.kafka.event.ContainerStoppedEvent;
 import org.springframework.kafka.test.EmbeddedKafkaBroker;
+import org.springframework.kafka.test.condition.LogLevels;
 import org.springframework.kafka.test.context.EmbeddedKafka;
 import org.springframework.kafka.test.utils.KafkaTestUtils;
 import org.springframework.test.context.junit.jupiter.SpringJUnitConfig;
@@ -59,25 +60,32 @@ public class ContainerGroupSequencerTests {
 	private static final LogAccessor LOGGER = new LogAccessor(LogFactory.getLog(ContainerGroupSequencerTests.class));
 
 	@Test
-	void sequenceCompletes(@Autowired Config config, @Autowired KafkaTemplate<Integer, String> template)
+	@LogLevels(classes = { ContainerGroupSequencerTests.class, ContainerGroupSequencer.class }, level = "DEBUG")
+	void sequenceCompletes(@Autowired Config config, @Autowired KafkaTemplate<Integer, String> template,
+			@Autowired ContainerGroupSequencer sequencer)
 			throws InterruptedException {
 
+		sequencer.start();
 		template.send("ContainerGroupSequencerTests", "test");
 		assertThat(config.stopped.await(10, TimeUnit.SECONDS))
 				.as("stopped latch still has a count of %d", config.stopped.getCount())
 				.isTrue();
 		List<String> order = config.order;
-		assertThat(order.get(0))
-				.as("out of order %s")
+		String expected = order.get(0);
+		assertThat(expected)
+				.as("out of order %s", expected)
 				.isIn("one", "two");
-		assertThat(order.get(1))
-				.as("out of order %s")
+		expected = order.get(1);
+		assertThat(expected)
+				.as("out of order %s", expected)
 				.isIn("one", "two");
-		assertThat(order.get(2))
-				.as("out of order %s")
+		expected = order.get(2);
+		assertThat(expected)
+				.as("out of order %s", expected)
 				.isIn("three", "four");
-		assertThat(order.get(3))
-				.as("out of order %s")
+		expected = order.get(3);
+		assertThat(expected)
+				.as("out of order %s", expected)
 				.isIn("three", "four");
 		assertThat(config.receivedAt.get(3) - config.receivedAt.get(0)).isGreaterThanOrEqualTo(1000);
 	}
@@ -95,24 +103,28 @@ public static class Config {
 
 		@KafkaListener(id = "one", topics = "ContainerGroupSequencerTests", containerGroup = "g1", concurrency = "2")
 		public void listen1(String in) {
+			LOGGER.debug(in);
 			this.order.add("one");
 			this.receivedAt.add(System.currentTimeMillis());
 		}
 
 		@KafkaListener(id = "two", topics = "ContainerGroupSequencerTests", containerGroup = "g1", concurrency = "2")
 		public void listen2(String in) {
+			LOGGER.debug(in);
 			this.order.add("two");
 			this.receivedAt.add(System.currentTimeMillis());
 		}
 
 		@KafkaListener(id = "three", topics = "ContainerGroupSequencerTests", containerGroup = "g2", concurrency = "2")
 		public void listen3(String in) {
+			LOGGER.debug(in);
 			this.order.add("three");
 			this.receivedAt.add(System.currentTimeMillis());
 		}
 
 		@KafkaListener(id = "four", topics = "ContainerGroupSequencerTests", containerGroup = "g2", concurrency = "2")
 		public void listen4(String in) {
+			LOGGER.debug(in);
 			this.order.add("four");
 			this.receivedAt.add(System.currentTimeMillis());
 		}
@@ -127,6 +139,7 @@ public void stopped(ContainerStoppedEvent event) {
 		ContainerGroupSequencer sequencer(KafkaListenerEndpointRegistry registry) {
 			ContainerGroupSequencer sequencer = new ContainerGroupSequencer(registry, 1000, "g1", "g2");
 			sequencer.setStopLastGroupWhenIdle(true);
+			sequencer.setAutoStartup(false);
 			return sequencer;
 		}