Change the gRPC o11y logName when sending logs to GCP. (grpc#9145)

* Change the gRPC o11y logName when sending logs to GCP.

Author: fengli79

gcp-observability/src/main/java/io/grpc/gcp/observability/logging/GcpLogSink.java

@@ -47,7 +47,8 @@ public class GcpLogSink implements Sink {
 
   // TODO(DNVindhya): Make cloud logging service a configurable value
   private static final String SERVICE_TO_EXCLUDE = "google.logging.v2.LoggingServiceV2";
-  private static final String DEFAULT_LOG_NAME = "grpc";
+  private static final String DEFAULT_LOG_NAME =
+      "microservices.googleapis.com%2Fobservability%2Fgrpc";
   private static final String K8S_MONITORED_RESOURCE_TYPE = "k8s_container";
   private static final Set<String> kubernetesResourceLabelSet
       = ImmutableSet.of("project_id", "location", "cluster_name", "namespace_name",
@@ -202,4 +203,4 @@ public synchronized void close() {
       logger.log(Level.SEVERE, "Caught exception while closing", e);
     }
   }
-}
+}

gcp-observability/src/test/java/io/grpc/gcp/observability/logging/GcpLogSinkTest.java

@@ -65,6 +65,9 @@ public class GcpLogSinkTest {
   private static final Map<String, String> customTags = ImmutableMap.of("KEY1", "Value1",
       "KEY2", "VALUE2");
   private static final long flushLimit = 10L;
+  // gRPC is expected to alway use this log name when reporting to GCP cloud logging.
+  private static final String expectedLogName =
+      "microservices.googleapis.com%2Fobservability%2Fgrpc";
   private final long seqId = 1;
   private final String destProjectName = "PROJECT";
   private final String serviceName = "service";
@@ -122,6 +125,7 @@ public void verifyWrite() throws Exception {
       LogEntry entry = it.next();
       System.out.println(entry);
       assertThat(entry.getPayload().getData()).isEqualTo(expectedStructLogProto);
+      assertThat(entry.getLogName()).isEqualTo(expectedLogName);
     }
     verifyNoMoreInteractions(mockLogging);
   }
@@ -143,6 +147,7 @@ public void verifyWriteWithTags() {
       assertThat(entry.getResource()).isEqualTo(expectedMonitoredResource);
       assertThat(entry.getLabels()).isEqualTo(customTags);
       assertThat(entry.getPayload().getData()).isEqualTo(expectedStructLogProto);
+      assertThat(entry.getLogName()).isEqualTo(expectedLogName);
     }
     verifyNoMoreInteractions(mockLogging);
   }