metadata: split context to incoming and outgoing

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

util/ctx/ctx.go

@@ -10,10 +10,9 @@ import (
 
 func FromRequest(r *http.Request) context.Context {
 	ctx := r.Context()
-	md, ok := metadata.FromContext(ctx)
+	md, ok := metadata.FromIncomingContext(ctx)
 	if !ok {
-		// create needed map with specific len
-		md = make(metadata.Metadata, len(r.Header)+2)
+		md = metadata.New(len(r.Header) + 2)
 	}
 	for key, val := range r.Header {
 		md.Set(key, strings.Join(val, ","))
@@ -22,5 +21,5 @@ func FromRequest(r *http.Request) context.Context {
 	md["Host"] = r.Host
 	// pass http method
 	md["Method"] = r.Method
-	return metadata.NewContext(ctx, md)
+	return metadata.NewIncomingContext(ctx, md)
 }

util/ctx/ctx_test.go

@@ -28,7 +28,7 @@ func TestRequestToContext(t *testing.T) {
 
 	for _, d := range testData {
 		ctx := FromRequest(d.request)
-		md, ok := metadata.FromContext(ctx)
+		md, ok := metadata.FromIncomingContext(ctx)
 		if !ok {
 			t.Fatalf("Expected metadata for request %+v", d.request)
 		}