添加了节点服务器，各个服务器之间支持多对多

node/api/api.proto

@@ -0,0 +1,34 @@
+syntax = "proto3";
+
+package node.api;
+option go_package = "hk4e/node/api;api";
+
+// 节点服务器注册发现服务
+service Discovery {
+  rpc RegisterServer (RegisterServerReq) returns (RegisterServerRsp) {} // 服务器启动注册获取appid
+  rpc GetServerAppId (GetServerAppIdReq) returns (GetServerAppIdRsp) {} // 随机获取某服务器的appid
+  rpc GetRegionEc2b (NullMsg) returns (RegionEc2b) {} // 获取区服密钥信息
+}
+
+message NullMsg {
+}
+
+message GetServerAppIdReq {
+  string server_type = 1;
+}
+
+message GetServerAppIdRsp {
+  string app_id = 1;
+}
+
+message RegisterServerReq {
+  string server_type = 1;
+}
+
+message RegisterServerRsp {
+  string app_id = 1;
+}
+
+message RegionEc2b {
+  bytes data = 1;
+}