add http header option (#142)

* add http header option

go.mod

@@ -3,7 +3,7 @@ module go.unistack.org/micro-server-http/v3
 go 1.16
 
 require (
-	go.unistack.org/micro/v3 v3.10.5
+	go.unistack.org/micro/v3 v3.10.9
 	golang.org/x/net v0.0.0-20220624214902-1bab6f366d9e
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

go.sum

@@ -74,8 +74,8 @@ github.com/xeipuuv/gojsonschema v1.2.0/go.mod h1:anYRn/JVcOK2ZgGU+IjEV4nwlhoK5sQ
 go.opentelemetry.io/proto/otlp v0.7.0/go.mod h1:PqfVotwruBrMGOCsRd/89rSnXhoiJIqeYNgFYFoEGnI=
 go.unistack.org/micro-proto/v3 v3.3.1 h1:nQ0MtWvP2G3QrpOgawVOPhpZZYkq6umTGDqs8FxJYIo=
 go.unistack.org/micro-proto/v3 v3.3.1/go.mod h1:cwRyv8uInM2I7EbU7O8Fx2Ls3N90Uw9UCCcq4olOdfE=
-go.unistack.org/micro/v3 v3.10.5 h1:m71XxBa3eOK83bBof0qGU1Fkfo0zYY7gXrtjdE7S6U4=
-go.unistack.org/micro/v3 v3.10.5/go.mod h1:gI4RkJKHLPW7KV6h4+ZBOZD997MRvFRXMPQIHpozikI=
+go.unistack.org/micro/v3 v3.10.9 h1:o8gdlE5JC9b2sm89RmztQPHnP4thN6FkGZyrKrahxX8=
+go.unistack.org/micro/v3 v3.10.9/go.mod h1:gI4RkJKHLPW7KV6h4+ZBOZD997MRvFRXMPQIHpozikI=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20200622213623-75b288015ac9/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/exp v0.0.0-20190121172915-509febef88a4/go.mod h1:CJ0aWSM057203Lf6IL+f9T1iT9GByDxfZKAQTCR3kQA=

handler.go

@@ -73,6 +73,7 @@ func (h *httpServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	}
 
 	ctx := context.WithValue(r.Context(), rspCodeKey{}, &rspCodeVal{})
+	ctx = context.WithValue(ctx, rspHeaderKey{}, &rspHeaderVal{})
 	md, ok := metadata.FromIncomingContext(ctx)
 	if !ok {
 		md = metadata.New(len(r.Header) + 8)
@@ -264,6 +265,13 @@ func (h *httpServer) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			w.Header().Set(k, v)
 		}
 	}
+	if md := getRspHeader(ctx); md != nil {
+		for k, v := range md {
+			for _, vv := range v {
+				w.Header().Add(k, vv)
+			}
+		}
+	}
 	if nct := w.Header().Get(metadata.HeaderContentType); nct != ct {
 		if cf, err = h.newCodec(nct); err != nil {
 			h.errorHandler(ctx, nil, w, r, err, http.StatusBadRequest)

options.go

@@ -38,6 +38,20 @@ type (
 	}
 )
 
+type (
+	rspHeaderKey struct{}
+	rspHeaderVal struct {
+		h http.Header
+	}
+)
+
+// SetRspHeader add response headers
+func SetRspHeader(ctx context.Context, h http.Header) {
+	if rsp, ok := ctx.Value(rspHeaderKey{}).(*rspHeaderVal); ok {
+		rsp.h = h
+	}
+}
+
 // SetRspCode saves response code in context, must be used by handler to specify http code
 func SetRspCode(ctx context.Context, code int) {
 	if rsp, ok := ctx.Value(rspCodeKey{}).(*rspCodeVal); ok {
@@ -45,6 +59,14 @@ func SetRspCode(ctx context.Context, code int) {
 	}
 }
 
+// getRspHeader get http.Header from context
+func getRspHeader(ctx context.Context) http.Header {
+	if rsp, ok := ctx.Value(rspHeaderKey{}).(*rspHeaderVal); ok {
+		return rsp.h
+	}
+	return nil
+}
+
 // GetRspCode used internally by generated http server handler
 func GetRspCode(ctx context.Context) int {
 	var code int