Implement monitor service

Author: akiradeveloper

sorock/proto-ext/sorock_monitor.proto

@@ -0,0 +1,26 @@
+syntax = "proto3";
+
+import "google/protobuf/empty.proto";
+
+package sorock_monitor;
+
+message Shard {
+  uint32 id = 1;
+}
+
+message Membership {
+  repeated string members = 1;
+}
+
+message LogMetrics {
+  uint64 head_index = 1;
+  uint64 snap_index = 2;
+  uint64 app_index = 3;
+  uint64 commit_index = 4;
+  uint64 last_index = 5;
+}
+
+service Monitor {
+  rpc GetMembership(Shard) returns (Membership) {}
+  rpc GetLogMetrics(Shard) returns (stream LogMetrics) {}
+}