Add ActiveUsers Check

lib/system_check/app/active_users_check.rb

+module SystemCheck
+  module App
+    class ActiveUsersCheck < SystemCheck::BaseCheck
+      set_name 'Active users:'
+
+      def multi_check
+        active_users = User.active.count
+
+        if active_users > 0
+          $stdout.puts active_users.to_s.color(:green)
+        else
+          $stdout.puts active_users.to_s.color(:red)
+        end
+      end
+    end
+  end
+end

lib/tasks/gitlab/check.rake

@@ -32,11 +32,11 @@ namespace :gitlab do
         SystemCheck::App::ProjectsHaveNamespaceCheck,
         SystemCheck::App::RedisVersionCheck,
         SystemCheck::App::RubyVersionCheck,
-        SystemCheck::App::GitVersionCheck
+        SystemCheck::App::GitVersionCheck,
+        SystemCheck::App::ActiveUsersCheck
       ]
 
       SystemCheck.run('GitLab', checks)
-      check_active_users
     end
   end
 
@@ -554,10 +554,6 @@ namespace :gitlab do
     end
   end
 
-  def check_active_users
-    puts "Active users: #{User.active.count}"
-  end
-
   def check_repo_integrity(repo_dir)
     puts "\nChecking repo at #{repo_dir.color(:yellow)}"