脚本内容：

vim install.mysql.sh
 
#!/bin/bash
 
[ -f /etc/init.d/functions ]&& . /etc/init.d/functions
 
###Check if user is root
if [ $UID -ne 0 ]; then
 echo "Error: You must be root to run this script, please use root to install"
 exit 1
fi
 
clear
echo "========================================================================="
echo "A tool to auto-compile & install MySQL 5.7.29 on Redhat/CentOS Linux "
echo "========================================================================="
#pkill -9 mysql
#date +%Y-%m-%d-%H-%M
#卸载系统自带的Mysql
#/bin/rpm -e $(/bin/rpm -qa | grep mysql|xargs) --nodeps
#/bin/rpm -e $(/bin/rpm -qa | grep mariadb|xargs) --nodeps
#/bin/rm -f /etc/my.cnf
 
#set mysql root password
 echo "==========================="
  mysqlrootpwd="$1"
  if [ "$1" = "" ]; then
    mysqlrootpwd="rootmysql"
  fi
 
#which MySQL Version do you want to install?
echo "==========================="
 
 isinstallmysql57="5.7.29"
 echo "Install MySQL 5.7.29,Please input y"
 read -p "(Please input y , n):"
# Initialize the installation related content.
 #Delete Old Mysql program
 rpm -qa|grep mysql
 rpm -e mysql
 
 
cat >>/etc/security/limits.conf<> /etc/sysctl.conf
 
echo "============================Install MySQL 5.7.29=================================="
 
#Backup old my.cnf
#rm -f /etc/my.cnf
if [ -s /etc/my.cnf ]; then
 mv /etc/my.cnf /etc/my.cnf.`date +%Y%m%d%H%M%S`.bak
fi
echo "============================MySQL 5.7.29 installing…………========================="
 
##define mysql directory configuration variable
Datadir=/data/mysql/data
Binlogdir=/data/mysql/binlog
Logdir=/data/mysql/logs
 
##yum install devel and wget mysql
yum install numactl
/usr/bin/wget -P /tmp http://mirrors.163.com/mysql/Downloads/MySQL-5.7/mysql-5.7.29-linux-glibc2.12-x86_64.tar.gz
sleep 2
tar xf /tmp/mysql-5.7.29-linux-glibc2.12-x86_64.tar.gz -C /usr/local/
ln -s /usr/local/mysql-5.7.29-linux-glibc2.12-x86_64 /usr/local/mysql
grep mysql /etc/passwd
RETVAL=$?
if [ $RETVAL -ne 0 ];then
 useradd mysql -s /sbin/nologin -M
  action "mysql user added successfully" /bin/true
 else
  action " $(echo -e "\e[31;47;5m mysql user already exists\e[0m")" /bin/false
fi
 
if [ ! -d "$Datadir" ]
then
 mkdir -p /data/mysql/data
fi
 
 
if [ ! -d "$Binlogdir" ]
then
 mkdir -p /data/mysql/binlog
fi
 
if [ ! -d "$Logdir" ]
then
 mkdir -p /data/mysql/logs
fi
 
chown -R mysql:mysql /data/mysql
chown -R mysql:mysql /usr/local/mysql
 
#edit /etc/my.cnf
#SERVERID=`ifconfig eth0 | grep "inet addr" | awk '{ print $2}'| awk -F. '{ print $3$4}'`
cat >>/etc/my.cnf< /etc/profile.d/mysql.sh
source /etc/profile.d/mysql.sh
echo "============================MySQL 5.7.29 install completed========================="
ps -eo start,cmd,pid|grep mysql
/usr/local/mysql/bin/mysqladmin -uroot -p"$Pass" password $mysqlrootpwd

[root@localhost ~]# sh install.mysql.sh mysqlroot
[root@localhost ~]# source /etc/profile.d/mysql.sh

说明： mysqlroot 为安装脚本修改MySQL服务默认密码后的新的密码

[root@localhost ~]# mysql -uroot -p'mysqlroot' -e "select now()"   
mysql: [Warning] Using a password on the command line interface can be insecure.
+---------------------+
| now()    |
+---------------------+
| 2020-10-13 16:18:47 |
+---------------------+

到此处MySQL服务启动成功！