allow enable log with cli, limit log size (#1384)

* impl logger rpc
* use size based appender
* add log args

easytier/src/proto/cli.proto

@@ -325,3 +325,31 @@ service StatsRpc {
   rpc GetStats(GetStatsRequest) returns (GetStatsResponse);
   rpc GetPrometheusStats(GetPrometheusStatsRequest) returns (GetPrometheusStatsResponse);
 }
+
+enum LogLevel {
+  DISABLED = 0;
+  ERROR = 1;
+  WARNING = 2;
+  INFO = 3;
+  DEBUG = 4;
+  TRACE = 5;
+}
+
+message SetLoggerConfigRequest {
+    LogLevel level = 1;
+}
+
+message SetLoggerConfigResponse {
+}
+
+message GetLoggerConfigRequest {
+}
+
+message GetLoggerConfigResponse {
+    LogLevel level = 1;
+}
+
+service LoggerRpc {
+  rpc SetLoggerConfig(SetLoggerConfigRequest) returns (SetLoggerConfigResponse);
+  rpc GetLoggerConfig(GetLoggerConfigRequest) returns (GetLoggerConfigResponse);
+}