Merge a39b723 into 8b0f780

server/kit/kitserver.go

@@ -8,13 +8,12 @@ import (
 	"net/http"
 	"os"
 
-	ocontext "golang.org/x/net/context"
-	"google.golang.org/grpc"
-
 	"github.com/go-kit/kit/log"
 	httptransport "github.com/go-kit/kit/transport/http"
 	grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware"
 	"github.com/pkg/errors"
+	ocontext "golang.org/x/net/context"
+	"google.golang.org/grpc"
 )
 
 // Server encapsulates all logic for registering and running a gizmo kit server.
@@ -137,22 +136,24 @@ func (s *Server) register(svc Service) {
 		return
 	}
 
-	gopts := []grpc.ServerOption{
-		grpc.UnaryInterceptor(
-			grpc_middleware.ChainUnaryServer(
-				grpc.UnaryServerInterceptor(
-					// inject logger into gRPC server and hook in go-kit middleware
-					func(ctx ocontext.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
-						ctx = context.WithValue(ctx, logKey, s.logger)
-						return svc.Middleware(func(ctx context.Context, req interface{}) (interface{}, error) {
-							return handler(ctx, req)
-						})(ctx, req)
-					}),
-			),
+	inters := []grpc.UnaryServerInterceptor{
+		grpc.UnaryServerInterceptor(
+			// inject logger into gRPC server and hook in go-kit middleware
+			func(ctx ocontext.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
+				ctx = context.WithValue(ctx, logKey, s.logger)
+				return svc.Middleware(func(ctx context.Context, req interface{}) (interface{}, error) {
+					return handler(ctx, req)
+				})(ctx, req)
+			},
 		),
 	}
-	gopts = append(gopts, svc.RPCOptions()...)
-	s.gsvr = grpc.NewServer(gopts...)
+	if mw := svc.RPCMiddleware(); mw != nil {
+		inters = append(inters, mw)
+	}
+
+	s.gsvr = grpc.NewServer(append(svc.RPCOptions(),
+		grpc.UnaryInterceptor(grpc_middleware.ChainUnaryServer(inters...)))...)
+
 	s.gsvr.RegisterService(gdesc, svc)
 }
 

server/kit/kitserver_test.go

@@ -16,6 +16,7 @@ import (
 	"google.golang.org/grpc"
 
 	"github.com/NYTimes/gizmo/server/kit"
+	"github.com/NYTimes/gziphandler"
 )
 
 func TestKitServer(t *testing.T) {
@@ -84,11 +85,14 @@ func TestKitServer(t *testing.T) {
 type server struct{}
 
 func (s *server) Middleware(e endpoint.Endpoint) endpoint.Endpoint {
-	return e
+	return endpoint.Endpoint(func(ctx context.Context, r interface{}) (interface{}, error) {
+		kit.LogMsgWithFields(ctx, "kit middleware!")
+		return e(ctx, r)
+	})
 }
 
 func (s *server) HTTPMiddleware(h http.Handler) http.Handler {
-	return h
+	return gziphandler.GzipHandler(h)
 }
 
 func (s *server) HTTPOptions() []httptransport.ServerOption {
@@ -114,6 +118,13 @@ func (s *server) RPCServiceDesc() *grpc.ServiceDesc {
 	return &_KitTestService_serviceDesc
 }
 
+func (s *server) RPCMiddleware() grpc.UnaryServerInterceptor {
+	return grpc.UnaryServerInterceptor(func(ctx ocontext.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		kit.LogMsgWithFields(ctx, "rpc middleware!")
+		return handler(ctx, req)
+	})
+}
+
 func (s *server) RPCOptions() []grpc.ServerOption {
 	return nil
 }

server/kit/service.go

@@ -67,10 +67,27 @@ type Service interface {
 	//  }
 	HTTPEndpoints() map[string]map[string]HTTPEndpoint
 
+	// RPCMiddleware is for any service-wide gRPC specific middleware
+	// for easy integration with 3rd party grpc.UnaryServerInterceptors like
+	// http://godoc.org/cloud.google.com/go/trace#Client.GRPCServerInterceptor
+	//
+	// The underlying kit server already uses the one available grpc.UnaryInterceptor
+	// grpc.ServerOption so attempting to pass your own in this Service's RPCOptions()
+	// will cause a panic at startup.
+	//
+	// If you want to apply multiple RPC middlewares,
+	// we recommend using:
+	// http://godoc.org/github.com/grpc-ecosystem/go-grpc-middleware#ChainUnaryServer
+	RPCMiddleware() grpc.UnaryServerInterceptor
+
 	// RPCServiceDesc allows services to declare an alternate gRPC
 	// representation of themselves to be hosted on the RPC_PORT (8081 by default).
 	RPCServiceDesc() *grpc.ServiceDesc
 
 	// RPCOptions are for service-wide gRPC server options.
+	//
+	// The underlying kit server already uses the one available grpc.UnaryInterceptor
+	// grpc.ServerOption so attempting to pass your own in this method will cause a panic
+	// at startup. We recommend using RPCMiddleware() to fill this need.
 	RPCOptions() []grpc.ServerOption
 }