API: Add ResourceConversion service (#1044)

Author: toddtreece

backend/admission.go

@@ -12,9 +12,6 @@ const (
 
 	// EndpointMutateAdmission friendly name for the mutate admission endpoint/handler.
 	EndpointMutateAdmission Endpoint = "mutateAdmission"
-
-	// EndpointConvertObject friendly name for the convert object endpoint/handler.
-	EndpointConvertObject Endpoint = "convertObject"
 )
 
 // AdmissionHandler is an EXPERIMENTAL service that allows checking objects before they are saved
@@ -26,13 +23,10 @@ type AdmissionHandler interface {
 	ValidateAdmission(context.Context, *AdmissionRequest) (*ValidationResponse, error)
 	// MutateAdmission converts the input into an object that can be saved, or rejects the request
 	MutateAdmission(context.Context, *AdmissionRequest) (*MutationResponse, error)
-	// ConvertObject is called to covert objects between different versions
-	ConvertObject(context.Context, *ConversionRequest) (*ConversionResponse, error)
 }
 
 type ValidateAdmissionFunc func(context.Context, *AdmissionRequest) (*ValidationResponse, error)
 type MutateAdmissionFunc func(context.Context, *AdmissionRequest) (*MutationResponse, error)
-type ConvertObjectFunc func(context.Context, *ConversionRequest) (*ConversionResponse, error)
 
 // Operation is the type of resource operation being checked for admission control
 // https://github.com/kubernetes/kubernetes/blob/v1.30.0/pkg/apis/admission/types.go#L158
@@ -69,18 +63,6 @@ type AdmissionRequest struct {
 	OldObjectBytes []byte `json:"old_object_bytes,omitempty"`
 }
 
-// ConversionRequest supports converting an object from on version to another
-type ConversionRequest struct {
-	// NOTE: this may not include app or datasource instance settings depending on the request
-	PluginContext PluginContext `json:"pluginContext,omitempty"`
-	// The object kind
-	Kind GroupVersionKind `json:"kind,omitempty"`
-	// Object is the object in the request.  This includes the full metadata envelope.
-	ObjectBytes []byte `json:"object_bytes,omitempty"`
-	// Target converted version
-	TargetVersion string `json:"target_version,omitempty"`
-}
-
 // Basic request to say if the validation was successful or not
 type ValidationResponse struct {
 	// Allowed indicates whether or not the admission request was permitted.
@@ -115,17 +97,6 @@ type MutationResponse struct {
 	ObjectBytes []byte `json:"object_bytes,omitempty"`
 }
 
-type ConversionResponse struct {
-	// Allowed indicates whether or not the admission request was permitted.
-	Allowed bool `json:"allowed,omitempty"`
-	// Result contains extra details into why an admission request was denied.
-	// This field IS NOT consulted in any way if "Allowed" is "true".
-	// +optional
-	Result *StatusResult `json:"result,omitempty"`
-	// Converted object bytes
-	ObjectBytes []byte `json:"object_bytes,omitempty"`
-}
-
 type StatusResult struct {
 	// Status of the operation.
 	// One of: "Success" or "Failure".

backend/admission_adapter.go

@@ -50,20 +50,3 @@ func (a *admissionSDKAdapter) MutateAdmission(ctx context.Context, req *pluginv2
 
 	return ToProto().MutationResponse(resp), nil
 }
-
-func (a *admissionSDKAdapter) ConvertObject(ctx context.Context, req *pluginv2.ConversionRequest) (*pluginv2.ConversionResponse, error) {
-	ctx = setupContext(ctx, EndpointConvertObject)
-	parsedReq := FromProto().ConversionRequest(req)
-
-	var resp *ConversionResponse
-	err := wrapHandler(ctx, parsedReq.PluginContext, func(ctx context.Context) (RequestStatus, error) {
-		var innerErr error
-		resp, innerErr = a.handler.ConvertObject(ctx, parsedReq)
-		return RequestStatusFromError(innerErr), innerErr
-	})
-	if err != nil {
-		return nil, err
-	}
-
-	return ToProto().ConversionResponse(resp), nil
-}

backend/app/manage.go

@@ -21,6 +21,9 @@ type ManageOpts struct {
 
 	// Stateless admission handler
 	AdmissionHandler backend.AdmissionHandler
+
+	// Stateless conversion handler
+	ConversionHandler backend.ConversionHandler
 }
 
 // Manage starts serving the app over gPRC with automatic instance management.
@@ -47,6 +50,7 @@ func Manage(pluginID string, instanceFactory InstanceFactoryFunc, opts ManageOpt
 		QueryDataHandler:    handler,
 		StreamHandler:       handler,
 		AdmissionHandler:    opts.AdmissionHandler,
+		ConversionHandler:   opts.ConversionHandler,
 		GRPCSettings:        opts.GRPCSettings,
 	})
 }

backend/conversion.go

@@ -0,0 +1,59 @@
+package backend
+
+import (
+	"context"
+)
+
+const (
+	// EndpointConvertObject friendly name for the convert object endpoint/handler.
+	EndpointConvertObject Endpoint = "convertObject"
+)
+
+// ConversionHandler is an EXPERIMENTAL service that allows converting objects between versions
+// This is modeled after the kubernetes CRD conversion webhooks.
+// Since grafana 11.1, this feature is under active development and will continue to evolve in 2024
+// This may also be replaced with a more native kubernetes solution that does not work with existing tooling
+
+type ConversionHandler interface {
+	// ConvertObject is called to covert objects between different versions
+	ConvertObjects(context.Context, *ConversionRequest) (*ConversionResponse, error)
+}
+
+type ConvertObjectsFunc func(context.Context, *ConversionRequest) (*ConversionResponse, error)
+
+type GroupVersion struct {
+	Group   string `json:"group,omitempty"`
+	Version string `json:"version,omitempty"`
+}
+
+// ConversionRequest supports converting an object from on version to another
+type ConversionRequest struct {
+	// NOTE: this may not include app or datasource instance settings depending on the request
+	PluginContext PluginContext `json:"pluginContext,omitempty"`
+	// UID is an identifier for the individual request/response. It allows distinguishing instances of requests which are
+	// otherwise identical (parallel requests, etc).
+	// The UID is meant to track the round trip (request/response) between the Kubernetes API server and the webhook, not the user request.
+	// It is suitable for correlating log entries between the webhook and apiserver, for either auditing or debugging.
+	UID string `json:"uid,omitempty"`
+	// TargetVersion is the version the object should be converted to.
+	TargetVersion GroupVersion `json:"target_version,omitempty"`
+	// Objects is the list of objects to convert. This contains the full metadata envelope.
+	Objects []RawObject `json:"objects,omitempty"`
+}
+
+type RawObject struct {
+	// Raw is the underlying serialization of this object.
+	Raw []byte `json:"-" `
+	// ContentType is the media type of the object.
+	ContentType string `json:"-"`
+}
+
+type ConversionResponse struct {
+	// UID is an identifier for the individual request/response.
+	// This should be copied over from the corresponding `request.uid`.
+	UID string `json:"uid,omitempty"`
+	// Result contains extra details into why an admission request was denied.
+	Result *StatusResult `json:"result,omitempty"`
+	// Objects is the list of converted version of `request.objects` if the `result` is successful, otherwise empty.
+	Objects []RawObject `json:"objects,omitempty"`
+}

backend/conversion_adapter.go

@@ -0,0 +1,34 @@
+package backend
+
+import (
+	"context"
+
+	"github.com/grafana/grafana-plugin-sdk-go/genproto/pluginv2"
+)
+
+type conversionSDKAdapter struct {
+	handler ConversionHandler
+}
+
+func newConversionSDKAdapter(handler ConversionHandler) *conversionSDKAdapter {
+	return &conversionSDKAdapter{
+		handler: handler,
+	}
+}
+
+func (a *conversionSDKAdapter) ConvertObjects(ctx context.Context, req *pluginv2.ConversionRequest) (*pluginv2.ConversionResponse, error) {
+	ctx = setupContext(ctx, EndpointConvertObject)
+	parsedReq := FromProto().ConversionRequest(req)
+
+	var resp *ConversionResponse
+	err := wrapHandler(ctx, parsedReq.PluginContext, func(ctx context.Context) (RequestStatus, error) {
+		var innerErr error
+		resp, innerErr = a.handler.ConvertObjects(ctx, parsedReq)
+		return RequestStatusFromError(innerErr), innerErr
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return ToProto().ConversionResponse(resp), nil
+}

backend/convert_from_protobuf.go

@@ -319,6 +319,31 @@ func (f ConvertFromProtobuf) GroupVersionKind(req *pluginv2.GroupVersionKind) Gr
 	}
 }
 
+// GroupVersion ...
+func (f ConvertFromProtobuf) GroupVersion(req *pluginv2.GroupVersion) GroupVersion {
+	return GroupVersion{
+		Group:   req.Group,
+		Version: req.Version,
+	}
+}
+
+// RawObject ...
+func (f ConvertFromProtobuf) RawObject(req *pluginv2.RawObject) RawObject {
+	return RawObject{
+		Raw:         req.Raw,
+		ContentType: req.ContentType,
+	}
+}
+
+// RawObjects ...
+func (f ConvertFromProtobuf) RawObjects(req []*pluginv2.RawObject) []RawObject {
+	rawObjects := make([]RawObject, len(req))
+	for i, r := range req {
+		rawObjects[i] = f.RawObject(r)
+	}
+	return rawObjects
+}
+
 // AdmissionRequest ...
 func (f ConvertFromProtobuf) AdmissionRequest(req *pluginv2.AdmissionRequest) *AdmissionRequest {
 	return &AdmissionRequest{
@@ -334,9 +359,9 @@ func (f ConvertFromProtobuf) AdmissionRequest(req *pluginv2.AdmissionRequest) *A
 func (f ConvertFromProtobuf) ConversionRequest(req *pluginv2.ConversionRequest) *ConversionRequest {
 	return &ConversionRequest{
 		PluginContext: f.PluginContext(req.PluginContext),
-		Kind:          f.GroupVersionKind(req.Kind),
-		ObjectBytes:   req.ObjectBytes,
-		TargetVersion: req.TargetVersion,
+		UID:           req.Uid,
+		Objects:       f.RawObjects(req.Objects),
+		TargetVersion: f.GroupVersion(req.TargetVersion),
 	}
 }
 
@@ -362,9 +387,9 @@ func (f ConvertFromProtobuf) ValidationResponse(rsp *pluginv2.ValidationResponse
 // ConversionResponse ...
 func (f ConvertFromProtobuf) ConversionResponse(rsp *pluginv2.ConversionResponse) *ConversionResponse {
 	return &ConversionResponse{
-		Allowed:     rsp.Allowed,
-		Result:      f.StatusResult(rsp.Result),
-		ObjectBytes: rsp.ObjectBytes,
+		UID:     rsp.Uid,
+		Result:  f.StatusResult(rsp.Result),
+		Objects: f.RawObjects(rsp.Objects),
 	}
 }