Plugins: Support Admission validation hooks (#87718)

pkg/tsdb/grafana-testdata-datasource/admission_handler.go

@@ -0,0 +1,87 @@
+package testdatasource
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"github.com/grafana/grafana-plugin-sdk-go/backend"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// ValidateAdmission implements backend.AdmissionHandler.
+func (s *Service) ValidateAdmission(ctx context.Context, req *backend.AdmissionRequest) (*backend.ValidationResponse, error) {
+	rsp, err := s.MutateAdmission(ctx, req)
+	if rsp != nil {
+		return &backend.ValidationResponse{
+			Allowed:  rsp.Allowed,
+			Result:   rsp.Result,
+			Warnings: rsp.Warnings,
+		}, err
+	}
+	return nil, err
+}
+
+// MutateAdmission implements backend.AdmissionHandler.
+func (s *Service) MutateAdmission(ctx context.Context, req *backend.AdmissionRequest) (*backend.MutationResponse, error) {
+	expected := (&backend.DataSourceInstanceSettings{}).GVK()
+	if req.Kind.Kind != expected.Kind && req.Kind.Group != expected.Group {
+		return getBadRequest("expected DataSourceInstanceSettings protobuf payload"), nil
+	}
+
+	// Convert the payload from protobuf to an SDK struct
+	settings, err := backend.DataSourceInstanceSettingsFromProto(req.ObjectBytes, "")
+	if err != nil {
+		return nil, err
+	}
+	if settings == nil {
+		return getBadRequest("missing datasource settings"), nil
+	}
+
+	switch settings.APIVersion {
+	case "", "v0alpha1":
+		// OK!
+	default:
+		return getBadRequest(fmt.Sprintf("expected apiVersion: v0alpha1, found: %s", settings.APIVersion)), nil
+	}
+	if settings.JSONData != nil {
+		anything := map[string]any{}
+		err := json.Unmarshal(settings.JSONData, &anything)
+		if err != nil || len(anything) > 0 {
+			return getBadRequest("Expected empty jsonData settings"), nil
+		}
+	}
+	if len(settings.DecryptedSecureJSONData) > 0 {
+		return getBadRequest("found unsupported secure json fields"), nil
+	}
+	if settings.URL != "" {
+		return getBadRequest("unsupported URL value"), nil
+	}
+	if settings.User != "" {
+		return getBadRequest("unsupported User value"), nil
+	}
+
+	pb, err := backend.DataSourceInstanceSettingsToProtoBytes(settings)
+	return &backend.MutationResponse{
+		Allowed:     true,
+		ObjectBytes: pb,
+	}, err
+}
+
+// ConvertObject implements backend.AdmissionHandler.
+func (s *Service) ConvertObject(ctx context.Context, req *backend.ConversionRequest) (*backend.ConversionResponse, error) {
+	return nil, fmt.Errorf("not implemented")
+}
+
+func getBadRequest(msg string) *backend.MutationResponse {
+	return &backend.MutationResponse{
+		Allowed: false,
+		Result: &backend.StatusResult{
+			Status:  "Failure",
+			Message: msg,
+			Reason:  string(metav1.StatusReasonBadRequest),
+			Code:    http.StatusBadRequest,
+		},
+	}
+}

pkg/tsdb/grafana-testdata-datasource/admission_handler_test.go

@@ -0,0 +1,68 @@
+package testdatasource
+
+import (
+	"context"
+	"encoding/json"
+	"testing"
+
+	"github.com/grafana/grafana-plugin-sdk-go/backend"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSettingsHandler(t *testing.T) {
+	svc := &Service{}
+	require.NotNil(t, svc)
+
+	// Check missing datasource
+	s, err := svc.MutateAdmission(context.Background(), &backend.AdmissionRequest{
+		PluginContext: backend.PluginContext{},
+	})
+	require.NoError(t, err)
+	require.False(t, s.Allowed)
+	require.Equal(t, int32(400), s.Result.Code)
+
+	// Empty is OK
+	s, _ = svc.MutateAdmission(context.Background(),
+		asAdmissionRequest(&backend.DataSourceInstanceSettings{
+			APIVersion: "v0alpha1",
+		}))
+	require.True(t, s.Allowed)
+
+	// Any values should be an error
+	s, err = svc.MutateAdmission(context.Background(),
+		asAdmissionRequest(&backend.DataSourceInstanceSettings{
+			JSONData: json.RawMessage(`{"hello": "world"}`), // Settings must be empty
+		}))
+	require.NoError(t, err)
+	require.False(t, s.Allowed)
+	require.Equal(t, int32(400), s.Result.Code)
+
+	// Any values should be an error
+	s, err = svc.MutateAdmission(context.Background(),
+		asAdmissionRequest(&backend.DataSourceInstanceSettings{
+			DecryptedSecureJSONData: map[string]string{
+				"A": "Value",
+			},
+		}))
+	require.NoError(t, err)
+	require.False(t, s.Allowed)
+	require.Equal(t, int32(400), s.Result.Code)
+
+	// Invalid API Version
+	s, err = svc.MutateAdmission(context.Background(),
+		asAdmissionRequest(&backend.DataSourceInstanceSettings{
+			APIVersion: "v1234",
+		}))
+	require.NoError(t, err)
+	require.False(t, s.Allowed)
+	require.Equal(t, int32(400), s.Result.Code)
+}
+
+func asAdmissionRequest(settings *backend.DataSourceInstanceSettings) *backend.AdmissionRequest {
+	req := &backend.AdmissionRequest{}
+	if settings != nil {
+		req.Kind = settings.GVK()
+		req.ObjectBytes, _ = backend.DataSourceInstanceSettingsToProtoBytes(settings)
+	}
+	return req
+}

pkg/tsdb/grafana-testdata-datasource/kinds/query.panel.schema.json

@@ -53,13 +53,17 @@
               "type"
             ],
             "properties": {
+              "apiVersion": {
+                "description": "The apiserver version",
+                "type": "string"
+              },
               "type": {
                 "description": "The datasource plugin type",
                 "type": "string",
                 "pattern": "^grafana-testdata-datasource$|^testdata$"
               },
               "uid": {
-                "description": "Datasource UID",
+                "description": "Datasource UID (NOTE: name in k8s)",
                 "type": "string"
               }
             },

pkg/tsdb/grafana-testdata-datasource/kinds/query.request.schema.json

@@ -63,13 +63,17 @@
               "type"
             ],
             "properties": {
+              "apiVersion": {
+                "description": "The apiserver version",
+                "type": "string"
+              },
               "type": {
                 "description": "The datasource plugin type",
                 "type": "string",
                 "pattern": "^grafana-testdata-datasource$|^testdata$"
               },
               "uid": {
-                "description": "Datasource UID",
+                "description": "Datasource UID (NOTE: name in k8s)",
                 "type": "string"
               }
             },

pkg/tsdb/grafana-testdata-datasource/testdata.go

@@ -47,6 +47,13 @@ func ProvideService() *Service {
 	return s
 }
 
+var (
+	_ backend.QueryDataHandler      = (*Service)(nil)
+	_ backend.CallResourceHandler   = (*Service)(nil)
+	_ backend.AdmissionHandler      = (*Service)(nil)
+	_ backend.CollectMetricsHandler = (*Service)(nil)
+)
+
 type Service struct {
 	logger          log.Logger
 	scenarios       map[kinds.TestDataQueryType]*Scenario