md copy from incoming to outgoing context

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

requestid.go

@@ -10,24 +10,36 @@ import (
 	"go.unistack.org/micro/v3/util/id"
 )
 
-// MetadataKey contains metadata key
-var MetadataKey = textproto.CanonicalMIMEHeaderKey("x-request-id")
+// DefaultMetadataKey contains metadata key
+var DefaultMetadataKey = textproto.CanonicalMIMEHeaderKey("x-request-id")
 
-// MetadataFunc wil be used if user not provide own func to fill metadata
-var MetadataFunc = func(ctx context.Context) (context.Context, error) {
-	md, ok := metadata.FromIncomingContext(ctx)
+// DefaultMetadataFunc wil be used if user not provide own func to fill metadata
+var DefaultMetadataFunc = func(ctx context.Context) (context.Context, error) {
+	imd, ok := metadata.FromIncomingContext(ctx)
 	if !ok {
-		md = metadata.New(1)
+		imd = metadata.New(1)
 	}
-	if _, ok = md.Get(MetadataKey); ok {
-		return ctx, nil
+	omd, ok := metadata.FromOutgoingContext(ctx)
+	if !ok {
+		omd = metadata.New(1)
 	}
-	uid, err := id.New()
-	if err != nil {
-		return ctx, err
+	v, iok := imd.Get(DefaultMetadataKey)
+	if iok {
+		if _, ook := omd.Get(DefaultMetadataKey); ook {
+			return ctx, nil
+		}
 	}
-	md.Set(MetadataKey, uid)
-	ctx = metadata.NewIncomingContext(ctx, md)
+	if !iok {
+		uid, err := id.New()
+		if err != nil {
+			return ctx, err
+		}
+		v = uid
+	}
+	imd.Set(DefaultMetadataKey, v)
+	omd.Set(DefaultMetadataKey, v)
+	ctx = metadata.NewIncomingContext(ctx, imd)
+	ctx = metadata.NewOutgoingContext(ctx, omd)
 	return ctx, nil
 }
 
@@ -48,7 +60,7 @@ func NewClientCallWrapper() client.CallWrapper {
 	return func(fn client.CallFunc) client.CallFunc {
 		return func(ctx context.Context, addr string, req client.Request, rsp interface{}, opts client.CallOptions) error {
 			var err error
-			if ctx, err = MetadataFunc(ctx); err != nil {
+			if ctx, err = DefaultMetadataFunc(ctx); err != nil {
 				return err
 			}
 			return fn(ctx, addr, req, rsp, opts)
@@ -58,7 +70,7 @@ func NewClientCallWrapper() client.CallWrapper {
 
 func (w *wrapper) Call(ctx context.Context, req client.Request, rsp interface{}, opts ...client.CallOption) error {
 	var err error
-	if ctx, err = MetadataFunc(ctx); err != nil {
+	if ctx, err = DefaultMetadataFunc(ctx); err != nil {
 		return err
 	}
 	return w.Client.Call(ctx, req, rsp, opts...)
@@ -66,7 +78,7 @@ func (w *wrapper) Call(ctx context.Context, req client.Request, rsp interface{},
 
 func (w *wrapper) Stream(ctx context.Context, req client.Request, opts ...client.CallOption) (client.Stream, error) {
 	var err error
-	if ctx, err = MetadataFunc(ctx); err != nil {
+	if ctx, err = DefaultMetadataFunc(ctx); err != nil {
 		return nil, err
 	}
 	return w.Client.Stream(ctx, req, opts...)
@@ -74,7 +86,7 @@ func (w *wrapper) Stream(ctx context.Context, req client.Request, opts ...client
 
 func (w *wrapper) Publish(ctx context.Context, msg client.Message, opts ...client.PublishOption) error {
 	var err error
-	if ctx, err = MetadataFunc(ctx); err != nil {
+	if ctx, err = DefaultMetadataFunc(ctx); err != nil {
 		return err
 	}
 	return w.Client.Publish(ctx, msg, opts...)
@@ -84,7 +96,7 @@ func NewServerHandlerWrapper() server.HandlerWrapper {
 	return func(fn server.HandlerFunc) server.HandlerFunc {
 		return func(ctx context.Context, req server.Request, rsp interface{}) error {
 			var err error
-			if ctx, err = MetadataFunc(ctx); err != nil {
+			if ctx, err = DefaultMetadataFunc(ctx); err != nil {
 				return err
 			}
 			return fn(ctx, req, rsp)
@@ -96,14 +108,20 @@ func NewServerSubscriberWrapper() server.SubscriberWrapper {
 	return func(fn server.SubscriberFunc) server.SubscriberFunc {
 		return func(ctx context.Context, msg server.Message) error {
 			var err error
-			md, ok := metadata.FromIncomingContext(ctx)
+			imd, ok := metadata.FromIncomingContext(ctx)
 			if !ok {
-				md = metadata.New(1)
+				imd = metadata.New(1)
 			}
-			if id, ok := msg.Header()[MetadataKey]; ok {
-				md.Set(MetadataKey, id)
-				ctx = metadata.NewIncomingContext(ctx, md)
-			} else if ctx, err = MetadataFunc(ctx); err != nil {
+			omd, ok := metadata.FromOutgoingContext(ctx)
+			if !ok {
+				omd = metadata.New(1)
+			}
+			if id, ok := msg.Header()[DefaultMetadataKey]; ok {
+				imd.Set(DefaultMetadataKey, id)
+				omd.Set(DefaultMetadataKey, id)
+				ctx = metadata.NewIncomingContext(ctx, imd)
+				ctx = metadata.NewOutgoingContext(ctx, omd)
+			} else if ctx, err = DefaultMetadataFunc(ctx); err != nil {
 				return err
 			}
 			return fn(ctx, msg)

requestid_test.go

@@ -0,0 +1,33 @@
+package requestid
+
+import (
+	"context"
+	"testing"
+
+	"go.unistack.org/micro/v3/metadata"
+)
+
+func TestDefaultMetadataFunc(t *testing.T) {
+	ctx := context.TODO()
+
+	nctx, err := DefaultMetadataFunc(ctx)
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+
+	imd, ok := metadata.FromIncomingContext(nctx)
+	if !ok {
+		t.Fatalf("md missing in incoming context")
+	}
+	omd, ok := metadata.FromOutgoingContext(nctx)
+	if !ok {
+		t.Fatalf("md missing in outgoing context")
+	}
+
+	_, iok := imd.Get(DefaultMetadataKey)
+	_, ook := omd.Get(DefaultMetadataKey)
+
+	if !iok || !ook {
+		t.Fatalf("missing metadata key value")
+	}
+}