Change DefaultSharedIndexInformer constructor to use Threads.threadFactory

While internally, the controllers use `Threads.threadFactory`,
`DefaultSharedIndexInformer` starts an ad-hoc thread. This makes it
invisible to instrumentation setup via
`Threads.setDefaultThreadFactory`. This changes the constructor to also
use the same.

Signed-off-by: Adrian Cole <[email protected]>

Author: codefromthecrypt

util/src/main/java/io/kubernetes/client/informer/impl/DefaultSharedIndexInformer.java

@@ -24,9 +24,11 @@
 import io.kubernetes.client.informer.cache.Indexer;
 import io.kubernetes.client.informer.cache.ProcessorListener;
 import io.kubernetes.client.informer.cache.SharedProcessor;
+import io.kubernetes.client.util.Threads;
 import java.util.Deque;
 import java.util.List;
 import java.util.Map;
+import java.util.concurrent.ThreadFactory;
 import java.util.function.BiConsumer;
 import java.util.function.Function;
 import org.apache.commons.collections4.CollectionUtils;
@@ -142,8 +144,9 @@ public DefaultSharedIndexInformer(
             resyncCheckPeriodMillis,
             exceptionHandler);
 
-    controllerThread =
-        new Thread(controller::run, "informer-controller-" + apiTypeClass.getSimpleName());
+    ThreadFactory threadFactory =
+        Threads.threadFactory("informer-controller-" + apiTypeClass.getSimpleName());
+    controllerThread = threadFactory.newThread(controller::run);
   }
 
   /** add event callback */

util/src/test/java/io/kubernetes/client/informer/impl/DefaultSharedIndexInformerTest.java

@@ -17,13 +17,21 @@
 import io.kubernetes.client.informer.cache.Indexer;
 import io.kubernetes.client.openapi.models.V1Pod;
 import io.kubernetes.client.openapi.models.V1PodList;
+import io.kubernetes.client.util.Threads;
+import java.util.concurrent.Executors;
+import java.util.concurrent.ThreadFactory;
 import java.util.function.BiConsumer;
 import org.junit.Rule;
 import org.junit.Test;
 import org.mockito.Mock;
 import org.mockito.junit.MockitoJUnit;
 import org.mockito.junit.MockitoRule;
 
+import static org.mockito.ArgumentMatchers.any;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+import static org.mockito.Mockito.when;
+
 public class DefaultSharedIndexInformerTest {
 
   private static final Class<V1Pod> anyApiType = V1Pod.class;
@@ -35,6 +43,25 @@ public class DefaultSharedIndexInformerTest {
   @Mock private DeltaFIFO deltaFIFOMock;
   @Mock private Indexer<V1Pod> indexerMock;
   @Mock private BiConsumer<Class<V1Pod>, Throwable> exceptionHandler;
+  @Mock private ThreadFactory threadFactory;
+  @Mock private Thread thread;
+
+  @Test
+  public void testConstructorUsesDefaultThreadFactory() {
+    when(threadFactory.newThread(any())).thenReturn(thread);
+
+    try {
+      Threads.setDefaultThreadFactory(threadFactory);
+      new DefaultSharedIndexInformer<>(
+          anyApiType, listerWatcher, anyResyncPeriod, deltaFIFOMock, indexerMock, exceptionHandler);
+    } finally { // revert to default
+      Threads.setDefaultThreadFactory(Executors.defaultThreadFactory());
+    }
+
+    verify(threadFactory).newThread(any());
+    verify(thread).setName("informer-controller-V1Pod");
+    verifyNoMoreInteractions(threadFactory, thread);
+  }
 
   @Test
   public void testConstructorWithExceptionHandlerExists() {