fix(peer_server) set content type to application/json in admin

server/peer_server_handlers.go

@@ -188,6 +188,7 @@ func (ps *PeerServer) RemoveHttpHandler(w http.ResponseWriter, req *http.Request
 
 // Returns a JSON-encoded cluster configuration.
 func (ps *PeerServer) getClusterConfigHttpHandler(w http.ResponseWriter, req *http.Request) {
+	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(ps.ClusterConfig())
 }
 
@@ -217,6 +218,7 @@ func (ps *PeerServer) setClusterConfigHttpHandler(w http.ResponseWriter, req *ht
 	log.Debugf("[recv] Update Cluster Config Request")
 	ps.server.Dispatch(c, w, req)
 
+	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(ps.ClusterConfig())
 }
 
@@ -230,6 +232,7 @@ func (ps *PeerServer) getMachinesHttpHandler(w http.ResponseWriter, req *http.Re
 		}
 	}
 
+	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(&machines)
 }
 
@@ -237,6 +240,7 @@ func (ps *PeerServer) getMachinesHttpHandler(w http.ResponseWriter, req *http.Re
 func (ps *PeerServer) getMachineHttpHandler(w http.ResponseWriter, req *http.Request) {
 	vars := mux.Vars(req)
 	m := ps.getMachineMessage(vars["name"], ps.raftServer.Leader())
+	w.Header().Set("Content-Type", "application/json")
 	json.NewEncoder(w).Encode(m)
 }