implement an admin rpc to fetch ulimit data

lib/commands/admin-rpc.js

@@ -2,6 +2,7 @@
 const nThen = require("nthen");
 const getFolderSize = require("get-folder-size");
 const Util = require("../common-util");
+const Ulimit = require("ulimit");
 
 var Fs = require("fs");
 
@@ -14,6 +15,10 @@ var getFileDescriptorCount = function (Env, server, cb) {
     });
 };
 
+var getFileDescriptorLimit = function (env, server, cb) {
+    Ulimit(cb);
+};
+
 var getActiveSessions = function (Env, Server, cb) {
     var stats = Server.getSessionStats();
     cb(void 0, [
@@ -113,6 +118,7 @@ var commands = {
     FLUSH_CACHE: flushCache,
     SHUTDOWN: shutdown,
     GET_FILE_DESCRIPTOR_COUNT: getFileDescriptorCount,
+    GET_FILE_DESCRIPTOR_LIMIT: getFileDescriptorLimit,
 };
 
 Admin.command = function (Env, safeKey, data, _cb, Server) {