add server interface interceptors

Signed-off-by: Adphi <philippe.adrien.nousse@gmail.com>

example/example.go

@@ -14,6 +14,7 @@ import (
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/spf13/cobra"
 	"google.golang.org/grpc"
+	"google.golang.org/grpc/health/grpc_health_v1"
 	"google.golang.org/grpc/metadata"
 	greflectsvc "google.golang.org/grpc/reflection/grpc_reflection_v1alpha"
 	"google.golang.org/protobuf/proto"
@@ -22,12 +23,18 @@ import (
 	"go.linka.cloud/grpc/client"
 	"go.linka.cloud/grpc/interceptors/auth"
 	"go.linka.cloud/grpc/interceptors/defaulter"
+	"go.linka.cloud/grpc/interceptors/iface"
 	metrics2 "go.linka.cloud/grpc/interceptors/metrics"
 	validation2 "go.linka.cloud/grpc/interceptors/validation"
 	"go.linka.cloud/grpc/logger"
 	"go.linka.cloud/grpc/service"
 )
 
+var (
+	_ iface.UnaryInterceptor  = (*GreeterHandler)(nil)
+	_ iface.StreamInterceptor = (*GreeterHandler)(nil)
+)
+
 type GreeterHandler struct {
 	UnimplementedGreeterServer
 }
@@ -50,6 +57,20 @@ func (g *GreeterHandler) SayHelloStream(req *HelloStreamRequest, s Greeter_SayHe
 	return nil
 }
 
+func (g *GreeterHandler) UnaryServerInterceptor() grpc.UnaryServerInterceptor {
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
+		logger.C(ctx).Infof("called service interface unary interceptor")
+		return handler(ctx, req)
+	}
+}
+
+func (g *GreeterHandler) StreamServerInterceptor() grpc.StreamServerInterceptor {
+	return func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		logger.C(ss.Context()).Infof("called service interface stream interceptor")
+		return handler(srv, ss)
+	}
+}
+
 func httpLogger(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(writer http.ResponseWriter, request *http.Request) {
 		start := time.Now()
@@ -115,14 +136,18 @@ func run(opts ...service.Option) {
 		service.WithGRPCWebPrefix("/grpc"),
 		service.WithMiddlewares(httpLogger),
 		service.WithInterceptors(metrics),
-		service.WithServerInterceptors(auth.NewServerInterceptors(auth.WithBasicValidators(func(ctx context.Context, user, password string) (context.Context, error) {
-			if !auth.Equals(user, "admin") || !auth.Equals(password, "admin") {
-				return ctx, fmt.Errorf("invalid user or password")
-			}
-			log.Infof("request authenticated")
-			return ctx, nil
-		}))),
+		service.WithServerInterceptors(
+			auth.NewServerInterceptors(auth.WithBasicValidators(func(ctx context.Context, user, password string) (context.Context, error) {
+				if !auth.Equals(user, "admin") || !auth.Equals(password, "admin") {
+					return ctx, fmt.Errorf("invalid user or password")
+				}
+				log.Infof("request authenticated")
+				return ctx, nil
+			})),
+		),
 		service.WithInterceptors(defaulter, validation),
+		// enable server interface interceptor
+		service.WithServerInterceptors(iface.New()),
 	)
 	svc, err = service.New(opts...)
 	if err != nil {
@@ -158,7 +183,13 @@ func run(opts ...service.Option) {
 		log.Fatal(err)
 	}
 	g := NewGreeterClient(s)
-	defer cancel()
+	h := grpc_health_v1.NewHealthClient(s)
+	hres, err := h.Check(ctx, &grpc_health_v1.HealthCheckRequest{})
+	if err != nil {
+		log.Fatal(err)
+	}
+	log.Infof("status: %v", hres.Status)
+
 	md := metadata.MD{}
 	res, err := g.SayHello(ctx, &HelloRequest{Name: "test"}, grpc.Header(&md))
 	if err != nil {

interceptors/iface/interceptors.go

@@ -0,0 +1,41 @@
+package iface
+
+import (
+	"context"
+
+	"google.golang.org/grpc"
+
+	"go.linka.cloud/grpc/interceptors"
+)
+
+type UnaryInterceptor interface {
+	UnaryServerInterceptor() grpc.UnaryServerInterceptor
+}
+
+type StreamInterceptor interface {
+	StreamServerInterceptor() grpc.StreamServerInterceptor
+}
+
+type iface struct{}
+
+func New() interceptors.ServerInterceptors {
+	return &iface{}
+}
+
+func (s iface) UnaryServerInterceptor() grpc.UnaryServerInterceptor {
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
+		if i, ok := info.Server.(UnaryInterceptor); ok {
+			return i.UnaryServerInterceptor()(ctx, req, info, handler)
+		}
+		return handler(ctx, req)
+	}
+}
+
+func (s iface) StreamServerInterceptor() grpc.StreamServerInterceptor {
+	return func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		if i, ok := srv.(StreamInterceptor); ok {
+			return i.StreamServerInterceptor()(srv, ss, info, handler)
+		}
+		return handler(srv, ss)
+	}
+}

interceptors/noop/interceptors.go

@@ -0,0 +1,39 @@
+package noop
+
+import (
+	"context"
+
+	"google.golang.org/grpc"
+
+	"go.linka.cloud/grpc/interceptors"
+)
+
+func New() interceptors.Interceptors {
+	return &noopInterceptor{}
+}
+
+type noopInterceptor struct{}
+
+func (m *noopInterceptor) UnaryServerInterceptor() grpc.UnaryServerInterceptor {
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (resp interface{}, err error) {
+		return handler(ctx, req)
+	}
+}
+
+func (m *noopInterceptor) StreamServerInterceptor() grpc.StreamServerInterceptor {
+	return func(srv interface{}, ss grpc.ServerStream, info *grpc.StreamServerInfo, handler grpc.StreamHandler) error {
+		return handler(srv, ss)
+	}
+}
+
+func (m *noopInterceptor) UnaryClientInterceptor() grpc.UnaryClientInterceptor {
+	return func(ctx context.Context, method string, req, reply interface{}, cc *grpc.ClientConn, invoker grpc.UnaryInvoker, opts ...grpc.CallOption) error {
+		return invoker(ctx, method, req, reply, cc, opts...)
+	}
+}
+
+func (m *noopInterceptor) StreamClientInterceptor() grpc.StreamClientInterceptor {
+	return func(ctx context.Context, desc *grpc.StreamDesc, cc *grpc.ClientConn, method string, streamer grpc.Streamer, opts ...grpc.CallOption) (grpc.ClientStream, error) {
+		return streamer(ctx, desc, cc, method, opts...)
+	}
+}

service/interceptors.go

@@ -0,0 +1,20 @@
+package service
+
+import (
+	"go.linka.cloud/grpc/interceptors"
+	"go.linka.cloud/grpc/interceptors/metadata"
+)
+
+func md(opts *options) interceptors.Interceptors {
+	var pairs []string
+	if opts.name != "" {
+		pairs = append(pairs, "grpc-service-name", opts.name)
+	}
+	if opts.version != "" {
+		pairs = append(pairs, "grpc-service-version", opts.version)
+	}
+	if len(pairs) != 0 {
+		return metadata.NewInterceptors(pairs...)
+	}
+	return nil
+}

service/service.go

@@ -27,7 +27,6 @@ import (
 	"google.golang.org/grpc/health/grpc_health_v1"
 	greflect "google.golang.org/grpc/reflection"
 
-	"go.linka.cloud/grpc/interceptors/metadata"
 	"go.linka.cloud/grpc/logger"
 	"go.linka.cloud/grpc/registry"
 	"go.linka.cloud/grpc/registry/noop"
@@ -76,20 +75,15 @@ func newService(opts ...Option) (*service, error) {
 	for _, f := range opts {
 		f(s.opts)
 	}
-	if s.opts.name != "" {
-		i := metadata.NewInterceptors("grpc-service-name", s.opts.name)
-		s.opts.unaryServerInterceptors = append([]grpc.UnaryServerInterceptor{i.UnaryServerInterceptor()}, s.opts.unaryServerInterceptors...)
-		s.opts.unaryClientInterceptors = append([]grpc.UnaryClientInterceptor{i.UnaryClientInterceptor()}, s.opts.unaryClientInterceptors...)
-		s.opts.streamServerInterceptors = append([]grpc.StreamServerInterceptor{i.StreamServerInterceptor()}, s.opts.streamServerInterceptors...)
-		s.opts.streamClientInterceptors = append([]grpc.StreamClientInterceptor{i.StreamClientInterceptor()}, s.opts.streamClientInterceptors...)
-	}
-	if s.opts.version != "" {
-		i := metadata.NewInterceptors("grpc-service-version", s.opts.version)
-		s.opts.unaryServerInterceptors = append([]grpc.UnaryServerInterceptor{i.UnaryServerInterceptor()}, s.opts.unaryServerInterceptors...)
-		s.opts.unaryClientInterceptors = append([]grpc.UnaryClientInterceptor{i.UnaryClientInterceptor()}, s.opts.unaryClientInterceptors...)
-		s.opts.streamServerInterceptors = append([]grpc.StreamServerInterceptor{i.StreamServerInterceptor()}, s.opts.streamServerInterceptors...)
-		s.opts.streamClientInterceptors = append([]grpc.StreamClientInterceptor{i.StreamClientInterceptor()}, s.opts.streamClientInterceptors...)
+
+	md := md(s.opts)
+	if md != nil {
+		s.opts.unaryServerInterceptors = append([]grpc.UnaryServerInterceptor{md.UnaryServerInterceptor()}, s.opts.unaryServerInterceptors...)
+		s.opts.unaryClientInterceptors = append([]grpc.UnaryClientInterceptor{md.UnaryClientInterceptor()}, s.opts.unaryClientInterceptors...)
+		s.opts.streamServerInterceptors = append([]grpc.StreamServerInterceptor{md.StreamServerInterceptor()}, s.opts.streamServerInterceptors...)
+		s.opts.streamClientInterceptors = append([]grpc.StreamClientInterceptor{md.StreamClientInterceptor()}, s.opts.streamClientInterceptors...)
 	}
+
 	if s.opts.mux == nil {
 		s.opts.mux = http.NewServeMux()
 	}