Make Pub/Sub integration tests less flaky (#2546) (#2547)

* Make PubTemplateIntegrationTests less flaky

spring-cloud-gcp-autoconfigure/src/test/java/org/springframework/cloud/gcp/autoconfigure/pubsub/it/PubSubTemplateIntegrationTests.java

@@ -27,13 +27,17 @@
 import java.util.concurrent.Future;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
+import java.util.concurrent.atomic.AtomicReference;
 import java.util.stream.Collectors;
 
 import com.fasterxml.jackson.annotation.JsonCreator;
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.google.protobuf.ByteString;
 import com.google.pubsub.v1.PubsubMessage;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.awaitility.Awaitility;
 import org.awaitility.Duration;
 import org.junit.BeforeClass;
 import org.junit.Test;
@@ -62,9 +66,12 @@
  * @author Chengyuan Zhao
  * @author Dmitry Solomakha
  * @author Daniel Zou
+ * @author Mike Eltsufin
  */
 public class PubSubTemplateIntegrationTests {
 
+	private static final Log LOGGER = LogFactory.getLog(PubSubTemplateIntegrationTests.class);
+
 	private ApplicationContextRunner contextRunner = new ApplicationContextRunner()
 			.withPropertyValues("spring.cloud.gcp.pubsub.subscriber.max-ack-extension-period=0")
 			.withConfiguration(AutoConfigurations.of(GcpContextAutoConfiguration.class,
@@ -94,7 +101,15 @@ public void testCreatePublishPullNextAndDelete() {
 			headers.put("cactuar", "tonberry");
 			headers.put("fujin", "raijin");
 			pubSubTemplate.publish(topicName, "tatatatata", headers).get();
-			PubsubMessage pubsubMessage = pubSubTemplate.pullNext(subscriptionName);
+
+			// get message
+			AtomicReference<PubsubMessage> pubsubMessageRef = new AtomicReference<>();
+			Awaitility.await().atMost(30, TimeUnit.SECONDS).until(
+					() -> {
+						pubsubMessageRef.set(pubSubTemplate.pullNext(subscriptionName));
+						return pubsubMessageRef.get() != null;
+					});
+			PubsubMessage pubsubMessage = pubsubMessageRef.get();
 
 			assertThat(pubsubMessage.getData()).isEqualTo(ByteString.copyFromUtf8("tatatatata"));
 			assertThat(pubsubMessage.getAttributesCount()).isEqualTo(2);
@@ -143,7 +158,8 @@ public void testPullAndAck() {
 					f.get(5, TimeUnit.SECONDS);
 				}
 				catch (InterruptedException | ExecutionException | TimeoutException ex) {
-					ex.printStackTrace();
+					LOGGER.error(ex);
+					Thread.currentThread().interrupt();
 				}
 			});