gRPC interface reflection. (#6722)

* WIP on gRPC interface reflection.

* Update docs in proto

* Add tests

* Add test

* Add route inside router

* Address nits

* ListInterfaces -> ListAllInterfaces

* Fix proto lint

* Remove stray println

* Update proto/cosmos/base/reflection/v1beta1/reflection.proto

Co-authored-by: Alexander Bezobchuk <alexanderbez@users.noreply.github.com>

* Update codec/types/interface_registry.go

Co-authored-by: Alexander Bezobchuk <alexanderbez@users.noreply.github.com>

* Update codec/types/interface_registry.go

Co-authored-by: Alexander Bezobchuk <alexanderbez@users.noreply.github.com>

* Add godoc

Co-authored-by: Amaury Martiny <amaury.martiny@protonmail.com>
Co-authored-by: Alexander Bezobchuk <alexanderbez@users.noreply.github.com>

baseapp/grpcrouter.go

@@ -9,6 +9,7 @@ import (
 	"google.golang.org/grpc/encoding"
 	"google.golang.org/grpc/encoding/proto"
 
+	"github.com/cosmos/cosmos-sdk/client/grpc/reflection"
 	"github.com/cosmos/cosmos-sdk/codec/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 )
@@ -17,9 +18,9 @@ var protoCodec = encoding.GetCodec(proto.Name)
 
 // GRPCQueryRouter routes ABCI Query requests to GRPC handlers
 type GRPCQueryRouter struct {
-	routes      map[string]GRPCQueryHandler
-	anyUnpacker types.AnyUnpacker
-	serviceData []serviceData
+	routes            map[string]GRPCQueryHandler
+	interfaceRegistry types.InterfaceRegistry
+	serviceData       []serviceData
 }
 
 // serviceData represents a gRPC service, along with its handler.
@@ -28,7 +29,7 @@ type serviceData struct {
 	handler     interface{}
 }
 
-var _ gogogrpc.Server
+var _ gogogrpc.Server = &GRPCQueryRouter{}
 
 // NewGRPCQueryRouter creates a new GRPCQueryRouter
 func NewGRPCQueryRouter() *GRPCQueryRouter {
@@ -67,8 +68,8 @@ func (qrt *GRPCQueryRouter) RegisterService(sd *grpc.ServiceDesc, handler interf
 				if err != nil {
 					return err
 				}
-				if qrt.anyUnpacker != nil {
-					return types.UnpackInterfaces(i, qrt.anyUnpacker)
+				if qrt.interfaceRegistry != nil {
+					return types.UnpackInterfaces(i, qrt.interfaceRegistry)
 				}
 				return nil
 			}, nil)
@@ -96,12 +97,14 @@ func (qrt *GRPCQueryRouter) RegisterService(sd *grpc.ServiceDesc, handler interf
 	})
 }
 
-// AnyUnpacker returns the AnyUnpacker for the router
-func (qrt *GRPCQueryRouter) AnyUnpacker() types.AnyUnpacker {
-	return qrt.anyUnpacker
-}
+// SetInterfaceRegistry sets the interface registry for the router.
+func (qrt *GRPCQueryRouter) SetInterfaceRegistry(interfaceRegistry types.InterfaceRegistry) {
+	qrt.interfaceRegistry = interfaceRegistry
 
-// SetAnyUnpacker sets the AnyUnpacker for the router
-func (qrt *GRPCQueryRouter) SetAnyUnpacker(anyUnpacker types.AnyUnpacker) {
-	qrt.anyUnpacker = anyUnpacker
+	// Once we have an interface registry, we can register the interface
+	// registry reflection gRPC service.
+	reflection.RegisterReflectionServiceServer(
+		qrt,
+		reflection.NewReflectionServiceServer(qrt.interfaceRegistry),
+	)
 }

baseapp/grpcrouter_helpers.go

@@ -24,9 +24,9 @@ type QueryServiceTestHelper struct {
 
 // NewQueryServerTestHelper creates a new QueryServiceTestHelper that wraps
 // the provided sdk.Context
-func NewQueryServerTestHelper(ctx sdk.Context, anyUnpacker types.AnyUnpacker) *QueryServiceTestHelper {
+func NewQueryServerTestHelper(ctx sdk.Context, interfaceRegistry types.InterfaceRegistry) *QueryServiceTestHelper {
 	qrt := NewGRPCQueryRouter()
-	qrt.SetAnyUnpacker(anyUnpacker)
+	qrt.SetInterfaceRegistry(interfaceRegistry)
 	return &QueryServiceTestHelper{GRPCQueryRouter: qrt, ctx: ctx}
 }
 
@@ -51,8 +51,8 @@ func (q *QueryServiceTestHelper) Invoke(_ gocontext.Context, method string, args
 		return err
 	}
 
-	if q.anyUnpacker != nil {
-		return types.UnpackInterfaces(reply, q.anyUnpacker)
+	if q.interfaceRegistry != nil {
+		return types.UnpackInterfaces(reply, q.interfaceRegistry)
 	}
 
 	return nil

baseapp/grpcrouter_test.go

@@ -15,7 +15,7 @@ import (
 func TestGRPCRouter(t *testing.T) {
 	qr := NewGRPCQueryRouter()
 	interfaceRegistry := testdata.NewTestInterfaceRegistry()
-	qr.SetAnyUnpacker(interfaceRegistry)
+	qr.SetInterfaceRegistry(interfaceRegistry)
 	testdata.RegisterTestServiceServer(qr, testdata.TestServiceImpl{})
 	helper := &QueryServiceTestHelper{
 		GRPCQueryRouter: qr,

client/grpc/reflection/reflection.go

@@ -0,0 +1,45 @@
+package reflection
+
+import (
+	"context"
+
+	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+
+	"github.com/cosmos/cosmos-sdk/codec/types"
+)
+
+type reflectionServiceServer struct {
+	interfaceRegistry types.InterfaceRegistry
+}
+
+// NewReflectionServiceServer creates a new reflectionServiceServer.
+func NewReflectionServiceServer(interfaceRegistry types.InterfaceRegistry) ReflectionServiceServer {
+	return &reflectionServiceServer{interfaceRegistry: interfaceRegistry}
+}
+
+var _ ReflectionServiceServer = (*reflectionServiceServer)(nil)
+
+// ListAllInterfaces implements the ListAllInterfaces method of the
+// ReflectionServiceServer interface.
+func (r reflectionServiceServer) ListAllInterfaces(_ context.Context, _ *ListAllInterfacesRequest) (*ListAllInterfacesResponse, error) {
+	ifaces := r.interfaceRegistry.ListAllInterfaces()
+
+	return &ListAllInterfacesResponse{InterfaceNames: ifaces}, nil
+}
+
+// ListImplementations implements the ListImplementations method of the
+// ReflectionServiceServer interface.
+func (r reflectionServiceServer) ListImplementations(_ context.Context, req *ListImplementationsRequest) (*ListImplementationsResponse, error) {
+	if req == nil {
+		return nil, status.Error(codes.InvalidArgument, "empty request")
+	}
+
+	if req.InterfaceName == "" {
+		return nil, status.Error(codes.InvalidArgument, "invalid interface name")
+	}
+
+	impls := r.interfaceRegistry.ListImplementations(req.InterfaceName)
+
+	return &ListImplementationsResponse{ImplementationMessageNames: impls}, nil
+}