CloudMonitoring: Improve error message (#46599)

pkg/tsdb/cloudmonitoring/cloudmonitoring.go

@@ -72,6 +72,8 @@ func ProvideService(httpClientProvider httpclient.Provider, tracer tracing.Trace
 		tracer:             tracer,
 		httpClientProvider: httpClientProvider,
 		im:                 datasource.NewInstanceManager(newInstanceSettings(httpClientProvider)),
+
+		gceDefaultProjectGetter: utils.GCEDefaultProject,
 	}
 
 	s.resourceHandler = httpadapter.New(s.newResourceMux())
@@ -91,7 +93,10 @@ func (s *Service) CheckHealth(ctx context.Context, req *backend.CheckHealthReque
 
 	defaultProject, err := s.getDefaultProject(ctx, *dsInfo)
 	if err != nil {
-		return nil, err
+		return &backend.CheckHealthResult{
+			Status:  backend.HealthStatusError,
+			Message: err.Error(),
+		}, nil
 	}
 
 	url := fmt.Sprintf("%v/v3/projects/%v/metricDescriptors", dsInfo.services[cloudMonitor].url, defaultProject)
@@ -128,6 +133,9 @@ type Service struct {
 	tracer             tracing.Tracer
 
 	resourceHandler backend.CallResourceHandler
+
+	// mocked in tests
+	gceDefaultProjectGetter func(ctx context.Context) (string, error)
 }
 
 type QueryModel struct {
@@ -612,7 +620,7 @@ func (s *Service) createRequest(ctx context.Context, dsInfo *datasourceInfo, pro
 
 func (s *Service) getDefaultProject(ctx context.Context, dsInfo datasourceInfo) (string, error) {
 	if dsInfo.authenticationType == gceAuthentication {
-		return utils.GCEDefaultProject(ctx)
+		return s.gceDefaultProjectGetter(ctx)
 	}
 	return dsInfo.defaultProject, nil
 }

pkg/tsdb/cloudmonitoring/cloudmonitoring_test.go

@@ -1,7 +1,9 @@
 package cloudmonitoring
 
 import (
+	"context"
 	"encoding/json"
+	"fmt"
 	"net/url"
 	"reflect"
 	"strings"
@@ -9,6 +11,8 @@ import (
 	"time"
 
 	"github.com/grafana/grafana-plugin-sdk-go/backend"
+	"github.com/grafana/grafana-plugin-sdk-go/backend/datasource"
+	"github.com/grafana/grafana-plugin-sdk-go/backend/instancemgmt"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -933,3 +937,29 @@ func baseReq() *backend.QueryDataRequest {
 	}
 	return query
 }
+
+func TestCheckHealth(t *testing.T) {
+	t.Run("and using GCE authentation should return proper error", func(t *testing.T) {
+		im := datasource.NewInstanceManager(func(s backend.DataSourceInstanceSettings) (instancemgmt.Instance, error) {
+			return &datasourceInfo{
+				authenticationType: gceAuthentication,
+			}, nil
+		})
+		service := &Service{
+			im: im,
+			gceDefaultProjectGetter: func(ctx context.Context) (string, error) {
+				return "", fmt.Errorf("not found!")
+			},
+		}
+		res, err := service.CheckHealth(context.Background(), &backend.CheckHealthRequest{
+			PluginContext: backend.PluginContext{
+				DataSourceInstanceSettings: &backend.DataSourceInstanceSettings{},
+			},
+		})
+		assert.Nil(t, err)
+		assert.Equal(t, &backend.CheckHealthResult{
+			Status:  backend.HealthStatusError,
+			Message: "not found!",
+		}, res)
+	})
+}