k8s/query+ds: catch query errors, fix datasourceProvider and expose prometheus (#85071)

.vscode/launch.json

@@ -23,6 +23,20 @@
           "--secure-port=8443", 
           "--runtime-config=testdata.datasource.grafana.app/v0alpha1=true"]
     },
+    {
+      "name": "Run API Server (query-localhost)",
+      "type": "go",
+      "request": "launch",
+      "mode": "auto",
+      "program": "${workspaceFolder}/pkg/cmd/grafana/",
+      "env": {},
+      "cwd": "${workspaceFolder}",
+      "args": ["apiserver", 
+          "--secure-port=8443", 
+          "--runtime-config=query.grafana.app/v0alpha1=true",
+          "--hg-url=http://localhost:3000",
+          "--hg-key=$HGAPIKEY"]
+    },
     {
       "name": "Attach to Chrome",
       "port": 9222,

pkg/registry/apis/datasource/plugincontext.go

@@ -31,6 +31,10 @@ type PluginDatasourceProvider interface {
 	GetInstanceSettings(ctx context.Context, uid string) (*backend.DataSourceInstanceSettings, error)
 }
 
+type ScopedPluginDatasourceProvider interface {
+	GetDatasourceProvider(pluginJson plugins.JSONData) PluginDatasourceProvider
+}
+
 // PluginContext requires adding system settings (feature flags, etc) to the datasource config
 type PluginContextWrapper interface {
 	PluginContextForDataSource(ctx context.Context, datasourceSettings *backend.DataSourceInstanceSettings) (backend.PluginContext, error)
@@ -39,18 +43,30 @@ type PluginContextWrapper interface {
 func ProvideDefaultPluginConfigs(
 	dsService datasources.DataSourceService,
 	dsCache datasources.CacheService,
-	contextProvider *plugincontext.Provider) PluginDatasourceProvider {
-	return &defaultPluginDatasourceProvider{
-		plugin: plugins.JSONData{
-			ID: datasources.DS_TESTDATA,
-		},
+	contextProvider *plugincontext.Provider) ScopedPluginDatasourceProvider {
+	return &cachingDatasourceProvider{
 		dsService:       dsService,
 		dsCache:         dsCache,
 		contextProvider: contextProvider,
 	}
 }
 
-type defaultPluginDatasourceProvider struct {
+type cachingDatasourceProvider struct {
+	dsService       datasources.DataSourceService
+	dsCache         datasources.CacheService
+	contextProvider *plugincontext.Provider
+}
+
+func (q *cachingDatasourceProvider) GetDatasourceProvider(pluginJson plugins.JSONData) PluginDatasourceProvider {
+	return &scopedDatasourceProvider{
+		plugin:          pluginJson,
+		dsService:       q.dsService,
+		dsCache:         q.dsCache,
+		contextProvider: q.contextProvider,
+	}
+}
+
+type scopedDatasourceProvider struct {
 	plugin          plugins.JSONData
 	dsService       datasources.DataSourceService
 	dsCache         datasources.CacheService
@@ -58,10 +74,11 @@ type defaultPluginDatasourceProvider struct {
 }
 
 var (
-	_ PluginDatasourceProvider = (*defaultPluginDatasourceProvider)(nil)
+	_ PluginDatasourceProvider       = (*scopedDatasourceProvider)(nil)
+	_ ScopedPluginDatasourceProvider = (*cachingDatasourceProvider)(nil)
 )
 
-func (q *defaultPluginDatasourceProvider) Get(ctx context.Context, uid string) (*v0alpha1.DataSourceConnection, error) {
+func (q *scopedDatasourceProvider) Get(ctx context.Context, uid string) (*v0alpha1.DataSourceConnection, error) {
 	info, err := request.NamespaceInfoFrom(ctx, true)
 	if err != nil {
 		return nil, err
@@ -77,7 +94,7 @@ func (q *defaultPluginDatasourceProvider) Get(ctx context.Context, uid string) (
 	return asConnection(ds, info.Value)
 }
 
-func (q *defaultPluginDatasourceProvider) List(ctx context.Context) (*v0alpha1.DataSourceConnectionList, error) {
+func (q *scopedDatasourceProvider) List(ctx context.Context) (*v0alpha1.DataSourceConnectionList, error) {
 	info, err := request.NamespaceInfoFrom(ctx, true)
 	if err != nil {
 		return nil, err
@@ -101,11 +118,9 @@ func (q *defaultPluginDatasourceProvider) List(ctx context.Context) (*v0alpha1.D
 	return result, nil
 }
 
-func (q *defaultPluginDatasourceProvider) GetInstanceSettings(ctx context.Context, uid string) (*backend.DataSourceInstanceSettings, error) {
+func (q *scopedDatasourceProvider) GetInstanceSettings(ctx context.Context, uid string) (*backend.DataSourceInstanceSettings, error) {
 	if q.contextProvider == nil {
-		// NOTE!!! this is only here for the standalone example
-		// if we cleanup imports this can throw an error
-		return nil, nil
+		return nil, fmt.Errorf("missing contextProvider")
 	}
 	return q.contextProvider.GetDataSourceInstanceSettings(ctx, uid)
 }

pkg/registry/apis/datasource/register.go

@@ -54,7 +54,7 @@ func RegisterAPIService(
 	features featuremgmt.FeatureToggles,
 	apiRegistrar builder.APIRegistrar,
 	pluginClient plugins.Client, // access to everything
-	datasources PluginDatasourceProvider,
+	datasources ScopedPluginDatasourceProvider,
 	contextProvider PluginContextWrapper,
 	pluginStore pluginstore.Store,
 	accessControl accesscontrol.AccessControl,
@@ -69,7 +69,8 @@ func RegisterAPIService(
 	all := pluginStore.Plugins(context.Background(), plugins.TypeDataSource)
 	ids := []string{
 		"grafana-testdata-datasource",
-		//	"prometheus",
+		"prometheus",
+		"graphite",
 	}
 
 	for _, ds := range all {
@@ -79,7 +80,7 @@ func RegisterAPIService(
 
 		builder, err = NewDataSourceAPIBuilder(ds.JSONData,
 			pluginClient,
-			datasources,
+			datasources.GetDatasourceProvider(ds.JSONData),
 			contextProvider,
 			accessControl,
 		)

pkg/registry/apis/query/query.go

@@ -119,7 +119,7 @@ func (b *QueryAPIBuilder) handleQuerySingleDatasource(ctx context.Context, req d
 		return nil, err
 	}
 
-	_, rsp, err := client.QueryData(ctx, *req.Request)
+	code, rsp, err := client.QueryData(ctx, *req.Request)
 	if err == nil && rsp != nil {
 		for _, q := range req.Request.Queries {
 			if q.ResultAssertions != nil {
@@ -135,6 +135,17 @@ func (b *QueryAPIBuilder) handleQuerySingleDatasource(ctx context.Context, req d
 			}
 		}
 	}
+
+	// Create a response object with the error when missing (happens for client errors like 404)
+	if rsp == nil && err != nil {
+		rsp = &backend.QueryDataResponse{Responses: make(backend.Responses)}
+		for _, q := range req.Request.Queries {
+			rsp.Responses[q.RefID] = backend.DataResponse{
+				Status: backend.Status(code),
+				Error:  err,
+			}
+		}
+	}
 	return rsp, err
 }
 
@@ -229,6 +240,9 @@ func (b *QueryAPIBuilder) handleExpressions(ctx context.Context, req parsedReque
 	if qdr == nil {
 		qdr = &backend.QueryDataResponse{}
 	}
+	if qdr.Responses == nil {
+		qdr.Responses = make(backend.Responses) // avoid NPE for lookup
+	}
 	now := start // <<< this should come from the original query parser
 	vars := make(mathexp.Vars)
 	for _, expression := range req.Expressions {