gcp/observability: filter logging from cloud ops endpoints calls

gcp/observability/logging.go

@@ -338,6 +338,11 @@ type binaryLogger struct {
 }
 
 func (bl *binaryLogger) GetMethodLogger(methodName string) iblog.MethodLogger {
+	// Prevent logging from logging, traces, and metrics API calls.
+	if strings.HasPrefix(methodName, "/google.logging.v2.LoggingServiceV2/") || strings.HasPrefix(methodName, "/google.monitoring.v3.MetricService/") ||
+		strings.HasPrefix(methodName, "/google.devtools.cloudtrace.v2.TraceService/") {
+		return nil
+	}
 	s, _, err := grpcutil.ParseMethod(methodName)
 	if err != nil {
 		logger.Infof("binarylogging: failed to parse %q: %v", methodName, err)

gcp/observability/logging_test.go

@@ -166,6 +166,7 @@ func (s) TestClientRPCEventsLogAll(t *testing.T) {
 	if _, err := ss.Client.UnaryCall(ctx, &grpc_testing.SimpleRequest{}); err != nil {
 		t.Fatalf("Unexpected error from UnaryCall: %v", err)
 	}
+
 	grpcLogEntriesWant := []*grpcLogEntry{
 		{
 			Type:        eventTypeClientHeader,
@@ -1056,6 +1057,65 @@ func (s) TestTranslateMetadata(t *testing.T) {
 	}
 }
 
+// TestCloudLoggingAPICallsFiltered tests that the observability plugin does not
+// emit logs for cloud logging API calls.
+func (s) TestCloudLoggingAPICallsFiltered(t *testing.T) {
+	fle := &fakeLoggingExporter{
+		t: t,
+	}
+
+	defer func(ne func(ctx context.Context, config *config) (loggingExporter, error)) {
+		newLoggingExporter = ne
+	}(newLoggingExporter)
+
+	newLoggingExporter = func(ctx context.Context, config *config) (loggingExporter, error) {
+		return fle, nil
+	}
+	configLogAll := &config{
+		ProjectID: "fake",
+		CloudLogging: &cloudLogging{
+			ClientRPCEvents: []clientRPCEvents{
+				{
+					Methods:          []string{"*"},
+					MaxMetadataBytes: 30,
+					MaxMessageBytes:  30,
+				},
+			},
+		},
+	}
+	cleanup, err := setupObservabilitySystemWithConfig(configLogAll)
+	if err != nil {
+		t.Fatalf("error setting up observability %v", err)
+	}
+	defer cleanup()
+
+	ss := &stubserver.StubServer{}
+	if err := ss.Start(nil); err != nil {
+		t.Fatalf("Error starting endpoint server: %v", err)
+	}
+	defer ss.Stop()
+
+	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
+	defer cancel()
+
+	// Any of the three cloud logging API calls should not cause any logs to be
+	// emitted, even though the configuration specifies to log any rpc
+	// regardless of method.
+	req := &grpc_testing.SimpleRequest{}
+	resp := &grpc_testing.SimpleResponse{}
+
+	ss.CC.Invoke(ctx, "/google.logging.v2.LoggingServiceV2/some-method", req, resp)
+	ss.CC.Invoke(ctx, "/google.monitoring.v3.MetricService/some-method", req, resp)
+	ss.CC.Invoke(ctx, "/google.devtools.cloudtrace.v2.TraceService/some-method", req, resp)
+	// The exporter should have received no new log entries due to these three
+	// calls, as they should be filtered out.
+	fle.mu.Lock()
+	defer fle.mu.Unlock()
+	if len(fle.entries) != 0 {
+		t.Fatalf("Unexpected length of entries %v, want 0", len(fle.entries))
+	}
+}
+
 func (s) TestMarshalJSON(t *testing.T) {
 	logEntry := &grpcLogEntry{
 		CallID:     "300-300-300",