题描述：Navicat 为管理方便，连接Linux 中Mariadb失败，如下如下错误：Host '*' is not allowed to connect to this MariaDB server
解决方案：
//允许用户testuser从ip为222.129.1.1的主机连接到mysql服务器，并使用testpassword作为密码
MariaDB [(none)]> grant all privileges on *.* to 'testuser'@'222.129.1.1' identified by 'testpassword' with grant option;
(若是允许所有ip：GRANT ALL PRIVILEGES ON *.* TO ‘testuser’@'%’ IDENTIFIED BY ‘testpassword’ WITH GRANT OPTION;)
MariaDB [(none)]> flush privileges; //刷新权限缓存
MariaDB [(none)]> show privileges;
MariaDB [(none)]> show grants for 'testuser'@'222.129.1.1'