Merge pull request 'fix swagger handler' (#172) from handler-swagger into v3

Reviewed-on: #172

handler.go

@@ -119,6 +119,12 @@ func (h *Server) HTTPHandlerFunc(handler interface{}) (http.HandlerFunc, error)
 		md["TransferEncoding"] = strings.Join(r.TransferEncoding, ",")
 		md["Host"] = r.Host
 		md["RequestURI"] = r.RequestURI
+		if r.TLS != nil {
+			md["TLS"] = "true"
+			md["TLS_ALPN"] = r.TLS.NegotiatedProtocol
+			md["TLS_ServerName"] = r.TLS.ServerName
+		}
+
 		ctx = metadata.NewIncomingContext(ctx, md)
 
 		path := r.URL.Path

handler/swagger/swagger.go

@@ -29,6 +29,12 @@ var Handler = func(dst map[string]interface{}, fsys fs.FS) http.HandlerFunc {
 			return
 		}
 
+		if dst == nil {
+			w.WriteHeader(http.StatusOK)
+			_, _ = w.Write(buf)
+			return
+		}
+
 		var src interface{}
 
 		if err = c.Unmarshal(buf, src); err != nil {