最近良心云10周年庆典放出了满1000-1000的优惠券，然后花8毛钱买了台3年的1H1G服务器。这配置，装个数据库够呛，于是花36元又买了个1年的1H1G数据库。但数据库没有提供外网，所以只能这8毛的服务器做中转，也足够了。
下载 MySQL Router软件包
wget https://dev.mysql.com/get/Downloads/MySQL-Router/mysql-router-community-8.0.21-1.el8.x86_64.rpm
安装 MySQL Router软件包
rpm -ivh mysql-router-community-8.0.21-1.el8.x86_64.rpm
返回提示
warning: mysql-router-community-8.0.21-1.el8.x86_64.rpm: Header V3 DSA/SHA1 Signature, key ID 5072e1f5: NOKEY
[/usr/lib/tmpfiles.d/mysqlrouter.conf:23] Line references path below legacy directory /var/run/, updating /var/run/mysqlrouter → /run/mysqlrouter; please update the tmpfiles.d/ drop-in file accordingly.
编辑配置文件，加上要代理的内网数据库
vim /etc/mysqlrouter/mysqlrouter.conf
# Copyright (c) 2015, 2019, Oracle and/or its affiliates. All rights reserved.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License, version 2.0,
# as published by the Free Software Foundation.
#
# This program is also distributed with certain software (including
# but not limited to OpenSSL) that is licensed under separate terms,
# as designated in a particular file or component or in included license
# documentation. The authors of MySQL hereby grant you an additional
# permission to link the program and your derivative works with the
# separately licensed software that they have included with MySQL.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License, version 2.0, for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
#
# MySQL Router configuration file
#
# Documentation is available at
# http://dev.mysql.com/doc/mysql-router/en/
[DEFAULT]
logging_folder = /var/log/mysqlrouter
runtime_folder = /var/run/mysqlrouter
config_folder = /etc/mysqlrouter
[logger]
level = INFO
# If no plugin is configured which starts a service, keepalive
# will make sure MySQL Router will not immediately exit. It is
# safe to remove once Router is configured.
[keepalive]
interval = 60
[routing:read_write]
bind_address = 0.0.0.0
bind_port = 3306
destinations = 172.27.16.12:3306
mode = read-write
启动 MySQL Router，并设置开机自启
systemctl start mysqlrouter.service
systemctl enable mysqlrouter.service
如果开机自启不了，可能是权限问题，可以更改下用户和用户组
chown mysqlrouter:mysqlrouter /usr/lib64/mysqlrouter
