CentOS 7系统优化脚本

一、介绍

作为一名运维，经常会部署各种用途的操作系统，但在这些工作中，我们会发现很多工作其实是重复性的劳动，操作的内容也是大同小异，基于这类情况，我们可以把相同的操作做成统一执行的脚本，不同的东西作为变量手动输入。节约下来的时间不就可以做更多有意义的事情吗？

最近在粉丝有推荐下发现一款比较好用的shell源码，也基于此改编了一下，分享给大家。

二、菜单

主菜单：

二级菜单：

主要实现系统的各类优化，比如常用的修改字符集、关闭selinux、关闭防火墙、安装常用工具和加快ssh登录等功能。

三、源码

#!/bin/sh
. /etc/rc.d/init.d/functions
export LANG=zh_CN.UTF-8
#一级菜单
menu1()
{
       clear
       cat <<eof
----------------------------------------
|****   欢迎使用cetnos7.9优化脚本    ****|
|****      博客地址: aaa.al         ****|
----------------------------------------
1. 一键优化
2. 自定义优化
3. 退出
EOF
       read -p "please enter your choice[1-3]:" num1
}
#二级菜单
menu2()
{
clear
cat <<eof
----------------------------------------
|****Please Enter Your Choice:[0-13]****|
----------------------------------------
1. 修改字符集
2. 关闭selinux
3. 关闭firewalld
4. 精简开机启动
5. 修改文件描述符
6. 安装常用工具及修改yum源
7. 优化系统内核
8. 加快ssh登录速度
9. 禁用ctrl+alt+del重启
10.设置时间同步
11.history优化
12.返回上级菜单
13.退出
EOF
read -p "please enter your choice[1-13]:" num2
}
#1.修改字符集
localeset()
{
echo "========================修改字符集========================="
cat > /etc/locale.conf <<eof
LANG="zh_CN.UTF-8"
#LANG="en_US.UTF-8"
SYSFONT="latarcyrheb-sun16"
EOF
source /etc/locale.conf
echo "#cat /etc/locale.conf"
cat /etc/locale.conf
action "完成修改字符集" /bin/true
echo "==========================================================="
sleep 2
}
#2.关闭selinux
selinuxset()  
{
selinux_status=`grep "SELINUX=disabled" /etc/sysconfig/selinux | wc -l`
echo "========================禁用SELINUX========================"
if [ $selinux_status -eq 0 ];then
 sed  -i "s#SELINUX=enforcing#SELINUX=disabled#g" /etc/sysconfig/selinux
 setenforce 0
 echo '#grep SELINUX=disabled /etc/sysconfig/selinux'
 grep SELINUX=disabled /etc/sysconfig/selinux
 echo '#getenforce'
 getenforce
else
 echo 'SELINUX已处于关闭状态'
 echo '#grep SELINUX=disabled /etc/sysconfig/selinux'
               grep SELINUX=disabled /etc/sysconfig/selinux
               echo '#getenforce'
               getenforce
fi
 action "完成禁用SELINUX" /bin/true
echo "==========================================================="
sleep 2
}
#3.关闭firewalld
firewalldset()
{
echo "=======================禁用firewalld========================"
systemctl stop firewalld.service &> /dev/null
echo '#firewall-cmd  --state'
firewall-cmd  --state
systemctl disable firewalld.service &> /dev/null
echo '#systemctl list-unit-files | grep firewalld'
systemctl list-unit-files | grep firewalld
action "完成禁用firewalld，生产环境下建议启用！" /bin/true
echo "==========================================================="
sleep 5
}
#4.精简开机启动
chkset()
{
echo "=======================精简开机启动========================"
systemctl disable auditd.service
systemctl disable postfix.service
systemctl disable dbus-org.freedesktop.NetworkManager.service
echo '#systemctl list-unit-files | grep -E "auditd|postfix|dbus-org.freedesktop.NetworkManager"'
systemctl list-unit-files | grep -E "auditd|postfix|dbus-org.freedesktop.NetworkManager"
action "完成精简开机启动" /bin/true
echo "==========================================================="
sleep 2
}
#5.修改文件描述符
limitset()
{
echo "======================修改文件描述符======================="
echo '* - nofile 65535'>/etc/security/limits.conf
ulimit -SHn 65535
echo "#cat /etc/security/limits.conf"
cat /etc/security/limits.conf
echo "#ulimit -Sn ; ulimit -Hn"
ulimit -Sn ; ulimit -Hn
action "完成修改文件描述符" /bin/true
echo "==========================================================="
sleep 2
}
#6.安装常用工具及修改yum源
yumset()
{
echo "=================安装常用工具及修改yum源==================="
yum install wget -y &> /dev/null
if [ $? -eq 0 ];then
 cd /etc/yum.repos.d/
 cp CentOS-Base.repo CentOS-Base.repo.$(date +%F)
 ping -c 1 mirrors.aliyun.com &> /dev/null
 if [ $? -eq 0 ];then
  wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo &> /dev/null
  yum clean all &> /dev/null
  yum makecache &> /dev/null
 else
  echo "无法连接网络"
      exit $?
   fi
else
 echo "wget安装失败"
 exit $?
fi
yum -y install ntpdate lsof net-tools telnet vim lrzsz tree nmap nc sysstat &> /dev/null
action "完成安装常用工具及修改yum源" /bin/true
echo "==========================================================="
sleep 2
}
#7. 优化系统内核
kernelset()
{
echo "======================优化系统内核========================="
chk_nf=`cat /etc/sysctl.conf | grep conntrack |wc -l`
if [ $chk_nf -eq 0 ];then
 cat >>/etc/sysctl.conf<<eof
net.ipv4.tcp_fin_timeout = 2
net.ipv4.tcp_tw_reuse = 1
net.ipv4.tcp_tw_recycle = 1
net.ipv4.tcp_syncookies = 1
net.ipv4.tcp_keepalive_time = 600
net.ipv4.ip_local_port_range = 4000 65000
net.ipv4.tcp_max_syn_backlog = 16384
net.ipv4.tcp_max_tw_buckets = 36000
net.ipv4.route.gc_timeout = 100
net.ipv4.tcp_syn_retries = 1
net.ipv4.tcp_synack_retries = 0
net.core.somaxconn = 16384
net.core.netdev_max_backlog = 16384
net.ipv4.tcp_max_orphans = 16384
net.netfilter.nf_conntrack_max = 25000000
net.netfilter.nf_conntrack_tcp_timeout_established = 180
net.netfilter.nf_conntrack_tcp_timeout_time_wait = 120
net.netfilter.nf_conntrack_tcp_timeout_close_wait = 60
net.netfilter.nf_conntrack_tcp_timeout_fin_wait = 120
EOF
sysctl -p
else
 echo "优化项已存在。"
fi
action "内核调优完成" /bin/true
echo "==========================================================="
sleep 2
}
#8.加快ssh登录速度
sshset()
{
echo "======================加快ssh登录速度======================"
sed -i 's#^GSSAPIAuthentication yes$#GSSAPIAuthentication no#g' /etc/ssh/sshd_config
sed -i 's/#UseDNS yes/UseDNS no/g' /etc/ssh/sshd_config
systemctl restart sshd.service
echo "#grep GSSAPIAuthentication /etc/ssh/sshd_config"
grep GSSAPIAuthentication /etc/ssh/sshd_config
echo "#grep UseDNS /etc/ssh/sshd_config"
grep UseDNS /etc/ssh/sshd_config
action "完成加快ssh登录速度" /bin/true
echo "==========================================================="
sleep 2
}
#9. 禁用ctrl+alt+del重启
restartset()
{
echo "===================禁用ctrl+alt+del重启===================="
rm -rf /usr/lib/systemd/system/ctrl-alt-del.target
action "完成禁用ctrl+alt+del重启" /bin/true
echo "==========================================================="
sleep 2
}
#10. 设置时间同步
ntpdateset()
{
echo "=======================设置时间同步========================"
yum -y install ntpdate &> /dev/null
if [ $? -eq 0 ];then
 /usr/sbin/ntpdate time.windows.com
 echo "*/5 * * * * /usr/sbin/ntpdate ntp.aliyun.com &>/dev/null" >> /var/spool/cron/root
else
 echo "ntpdate安装失败"
 exit $?
fi
action "完成设置时间同步" /bin/true
echo "==========================================================="
sleep 2
}
#11. history优化
historyset()
{
echo "========================history优化========================"
chk_his=`cat /etc/profile | grep HISTTIMEFORMAT |wc -l`
if [ $chk_his -eq 0 ];then
 cat >> /etc/profile <<'EOF'
#设置history格式
export HISTTIMEFORMAT="[%Y-%m-%d %H:%M:%S] [`whoami`] [`who am i|awk '{print $NF}'|sed -r 's#[()]##g'`]: "
#记录shell执行的每一条命令
export PROMPT_COMMAND='
if [ -z "$OLD_PWD" ];then
   export OLD_PWD=$PWD;
fi;
if [ ! -z "$LAST_CMD" ] && [ "$(history 1)" != "$LAST_CMD" ]; then
   logger -t `whoami`_shell_dir "[$OLD_PWD]$(history 1)";
fi;
export LAST_CMD="$(history 1)";
export OLD_PWD=$PWD;'
EOF
 source /etc/profile
else
 echo "优化项已存在。"
fi
action "完成history优化" /bin/true
echo "==========================================================="
sleep 2
}
#控制函数
main()
{
menu1
case $num1 in
 1)
  localeset
  selinuxset
  firewalldset
  chkset
  limitset
  yumset
  kernelset
  sshset
  restartset
  ntpdateset
  historyset
  ;;
 2)
  menu2
  case $num2 in
                 1)
                   localeset
                   ;;
                 2)
                   selinuxset
                   ;;
                 3)
                   firewalldset
                   ;;
                 4)
                   chkset
                   ;;
                 5)
                   limitset
                   ;;
                  6)      
           yumset
                   ;;
                 7)
                   kernelset
                   ;;
                 8)
                   sshset
                   ;;
                 9)
                   restartset
                   ;;
                 10)
                   ntpdateset
                   ;;
   11)
     historyset
     ;;
   12)
     main
     ;;
   13)
     exit
     ;;
   *)
     echo 'Please select a number from [1-13].'
     ;;
  esac
  ;;
 3)
  exit
  ;;
 *)
  echo 'Err:Please select a number from [1-3].'
  sleep 3
  main
  ;;
esac
}
main $*

将其保存为init.sh，然后赋予执行权限后执行即可。

chmod +x init.sh && ./init.sh

如果这样来回地复制粘贴很麻烦，也可以通过我的一键命令执行，同样能达到上面的效果：

bash -c "$(curl -L s.aaa.al/init.sh)"

最后，如果大家有想实现的功能，也可以在原有脚本的基础上进行修改实现。