Wire up data source config metrics correctly

Fix metrics for data source configuration CRUD.

Make sure to only create one histogram and only register it with prometheus once.

pkg/registry/apis/datasource/legacy_store.go

@@ -57,6 +57,11 @@ func (s *legacyStorage) ConvertToTable(ctx context.Context, object runtime.Objec
 }
 
 func (s *legacyStorage) List(ctx context.Context, options *internalversion.ListOptions) (runtime.Object, error) {
+	start := time.Now()
+	defer func() {
+		metricutil.ObserveWithExemplar(ctx, s.dsConfigHandlerRequestsDuration.WithLabelValues("new", "List"), time.Since(start).Seconds())
+	}()
+
 	return s.datasources.ListDataSources(ctx)
 }
 

pkg/registry/apis/datasource/register.go

@@ -5,6 +5,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"maps"
+	"sync"
 
 	"github.com/prometheus/client_golang/prometheus"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -39,15 +40,18 @@ var (
 type DataSourceAPIBuilder struct {
 	datasourceResourceInfo utils.ResourceInfo
 
-	pluginJSON           plugins.JSONData
-	client               PluginClient // will only ever be called with the same plugin id!
-	datasources          PluginDatasourceProvider
-	contextProvider      PluginContextWrapper
-	accessControl        accesscontrol.AccessControl
-	queryTypes           *queryV0.QueryTypeDefinitionList
-	configCrudUseNewApis bool
+	pluginJSON                      plugins.JSONData
+	client                          PluginClient // will only ever be called with the same plugin id!
+	datasources                     PluginDatasourceProvider
+	contextProvider                 PluginContextWrapper
+	accessControl                   accesscontrol.AccessControl
+	queryTypes                      *queryV0.QueryTypeDefinitionList
+	configCrudUseNewApis            bool
+	dsConfigHandlerRequestsDuration *prometheus.HistogramVec
 }
 
+var dsConfigHandlerRequestsDuration *prometheus.HistogramVec
+
 func RegisterAPIService(
 	features featuremgmt.FeatureToggles,
 	apiRegistrar builder.APIRegistrar,
@@ -63,6 +67,15 @@ func RegisterAPIService(
 		return nil, nil
 	}
 
+	sync.OnceFunc(func() {
+		dsConfigHandlerRequestsDuration = metricutil.NewHistogramVec(prometheus.HistogramOpts{
+			Namespace: "grafana",
+			Name:      "ds_config_handler_k8s_requests_duration_seconds",
+			Help:      "Duration of requests handled by datasource configuration handlers",
+		}, []string{"code_path", "handler"})
+		reg.MustRegister(dsConfigHandlerRequestsDuration)
+	})()
+
 	var err error
 	var builder *DataSourceAPIBuilder
 
@@ -87,6 +100,7 @@ func RegisterAPIService(
 			features.IsEnabledGlobally(featuremgmt.FlagDatasourceQueryTypes),
 			//nolint:staticcheck // not yet migrated to OpenFeature
 			features.IsEnabledGlobally(featuremgmt.FlagQueryServiceWithConnections),
+			dsConfigHandlerRequestsDuration,
 		)
 		if err != nil {
 			return nil, err
@@ -114,6 +128,7 @@ func NewDataSourceAPIBuilder(
 	accessControl accesscontrol.AccessControl,
 	loadQueryTypes bool,
 	configCrudUseNewApis bool,
+	dsConfigHandlerRequestsDuration *prometheus.HistogramVec,
 ) (*DataSourceAPIBuilder, error) {
 	group, err := plugins.GetDatasourceGroupNameFromPluginID(plugin.ID)
 	if err != nil {
@@ -121,13 +136,14 @@ func NewDataSourceAPIBuilder(
 	}
 
 	builder := &DataSourceAPIBuilder{
-		datasourceResourceInfo: datasourceV0.DataSourceResourceInfo.WithGroupAndShortName(group, plugin.ID),
-		pluginJSON:             plugin,
-		client:                 client,
-		datasources:            datasources,
-		contextProvider:        contextProvider,
-		accessControl:          accessControl,
-		configCrudUseNewApis:   configCrudUseNewApis,
+		datasourceResourceInfo:          datasourceV0.DataSourceResourceInfo.WithGroupAndShortName(group, plugin.ID),
+		pluginJSON:                      plugin,
+		client:                          client,
+		datasources:                     datasources,
+		contextProvider:                 contextProvider,
+		accessControl:                   accessControl,
+		configCrudUseNewApis:            configCrudUseNewApis,
+		dsConfigHandlerRequestsDuration: dsConfigHandlerRequestsDuration,
 	}
 	if loadQueryTypes {
 		// In the future, this will somehow come from the plugin
@@ -218,14 +234,11 @@ func (b *DataSourceAPIBuilder) UpdateAPIGroupInfo(apiGroupInfo *genericapiserver
 
 	if b.configCrudUseNewApis {
 		legacyStore := &legacyStorage{
-			datasources:  b.datasources,
-			resourceInfo: &ds,
-			dsConfigHandlerRequestsDuration: metricutil.NewHistogramVec(prometheus.HistogramOpts{
-				Namespace: "grafana",
-				Name:      "ds_config_handler_requests_duration_seconds",
-				Help:      "Duration of requests handled by datasource configuration handlers",
-			}, []string{"code_path", "handler"}),
+			datasources:                     b.datasources,
+			resourceInfo:                    &ds,
+			dsConfigHandlerRequestsDuration: b.dsConfigHandlerRequestsDuration,
 		}
+
 		unified, err := grafanaregistry.NewRegistryStore(opts.Scheme, ds, opts.OptsGetter)
 		if err != nil {
 			return err