[Disk Manager]: Fix incorrect grpc facade error reporting (#2469)

We did not report errors except context cancellation in grpc facade.

cloud/disk_manager/internal/pkg/facade/facade_test/facade_test.go

@@ -3,8 +3,10 @@ package facade_test
 import (
 	"testing"
 
+	"github.com/golang/protobuf/ptypes/empty"
 	"github.com/stretchr/testify/require"
 	disk_manager "github.com/ydb-platform/nbs/cloud/disk_manager/api"
+	"github.com/ydb-platform/nbs/cloud/disk_manager/internal/pkg/facade/testcommon"
 	"github.com/ydb-platform/nbs/cloud/tasks/errors"
 	"google.golang.org/protobuf/proto"
 )
@@ -48,3 +50,47 @@ func TestFacadeErrorDetails(t *testing.T) {
 	errorDetails1.Message = "ZYX"
 	check()
 }
+
+func TestFacadeShouldSendErrorMetrics(t *testing.T) {
+	ctx := testcommon.NewContext()
+	errorsCount := testcommon.GetCounter(
+		t,
+		"errors",
+		map[string]string{
+			"component": "grpc_facade",
+			"request":   "DiskService.Create",
+		},
+	)
+	client, err := testcommon.NewClient(ctx)
+	require.NoError(t, err)
+	defer client.Close()
+
+	diskID := t.Name()
+	reqCtx := testcommon.GetRequestContext(t, ctx)
+	_, err = client.CreateDisk(reqCtx, &disk_manager.CreateDiskRequest{
+		Src: &disk_manager.CreateDiskRequest_SrcEmpty{
+			SrcEmpty: &empty.Empty{},
+		},
+		// Incorrect size to trigger errors
+		Size: 1,
+		Kind: disk_manager.DiskKind_DISK_KIND_SSD,
+		DiskId: &disk_manager.DiskId{
+			ZoneId: "zone-a",
+			DiskId: diskID,
+		},
+	})
+	require.Error(t, err)
+	newErrorsCount := testcommon.GetCounter(
+		t,
+		"errors",
+		map[string]string{
+			"component": "grpc_facade",
+			"request":   "DiskService.Create",
+		},
+	)
+	require.GreaterOrEqual(
+		t,
+		newErrorsCount-errorsCount,
+		float64(1),
+	)
+}

cloud/disk_manager/internal/pkg/facade/interceptor.go

@@ -216,7 +216,7 @@ func (i *interceptor) intercept(
 	if err != nil {
 		logging.Warn(ctx, "%v failed, err=%v", requestName, err)
 		// Don't report errors when ctx is cancelled.
-		if ctx.Err() != nil {
+		if ctx.Err() == nil {
 			requestStats.onError(err)
 		}
 	}

cloud/disk_manager/internal/pkg/facade/testcommon/common.go

@@ -11,6 +11,8 @@ import (
 	"time"
 
 	"github.com/golang/protobuf/ptypes/empty"
+	prometheus_client "github.com/prometheus/client_model/go"
+	"github.com/prometheus/common/expfmt"
 	"github.com/stretchr/testify/require"
 	disk_manager "github.com/ydb-platform/nbs/cloud/disk_manager/api"
 	internal_client "github.com/ydb-platform/nbs/cloud/disk_manager/internal/pkg/client"
@@ -646,3 +648,55 @@ func CheckErrorDetails(
 		require.Equal(t, message, errorDetails.Message)
 	}
 }
+
+////////////////////////////////////////////////////////////////////////////////
+
+func GetCounter(t *testing.T, name string, labels map[string]string) float64 {
+	resp, err := http.Get(
+		fmt.Sprintf(
+			"http://localhost:%s/metrics/",
+			os.Getenv("DISK_MANAGER_RECIPE_DISK_MANAGER_MON_PORT"),
+		),
+	)
+	require.NoError(t, err)
+	defer resp.Body.Close()
+
+	parser := expfmt.TextParser{}
+	metricFamilies, err := parser.TextToMetricFamilies(resp.Body)
+	require.NoError(t, err)
+
+	retrievedMetrics, ok := metricFamilies[name]
+	require.True(t, ok)
+	for _, metricValue := range retrievedMetrics.GetMetric() {
+		if metricMatchesLabel(labels, metricValue) {
+			return metricValue.GetCounter().GetValue()
+		}
+	}
+
+	require.Failf(t, "No counter with name %s", name)
+	return 0
+}
+
+func metricMatchesLabel(
+	labels map[string]string,
+	metric *prometheus_client.Metric,
+) bool {
+
+	metricLabels := make(map[string]string)
+	for _, label := range metric.GetLabel() {
+		metricLabels[label.GetName()] = label.GetValue()
+	}
+
+	for name, value := range labels {
+		foundValue, ok := metricLabels[name]
+		if !ok {
+			return false
+		}
+
+		if foundValue != value {
+			return false
+		}
+	}
+
+	return true
+}

cloud/disk_manager/test/recipe/__main__.py

@@ -226,6 +226,7 @@ def start(argv):
         )
         disk_managers.append(disk_manager)
         disk_manager.start()
+    set_env("DISK_MANAGER_RECIPE_DISK_MANAGER_MON_PORT", str(disk_managers[0].monitoring_port))
 
     dataplane_disk_managers_count = 1
     for _ in range(0, dataplane_disk_managers_count):

cloud/disk_manager/test/recipe/disk_manager_launcher.py

@@ -472,3 +472,7 @@ def port(self):
     @property
     def server_config(self):
         return self.__server_config
+
+    @property
+    def monitoring_port(self):
+        return self.__monitoring_port