centos系统初始化脚本

#!/bin/bash
# 初始化系统脚本
# 适用centos6 和centos7
#
PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin
export PATH
cur_dir=$(pwd)
gcc_version=`rpm -qagcc | awk -F '[-]' '{print $2}'`
 
VERSION=`cat /etc/issue| grep '6.'`
if ["$VERSION" == "" ];then
    VERSION='centos7'
else
    VERSION='centos6'
fi
 
#更改为163的源
yum install wget -y
mv/etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup
if [ $VERSION =='centos7' ];then
    wget http://mirrors.163.com/.help/CentOS7-Base-163.repo
    mv CentOS7-Base-163.repo  /etc/yum.repos.d/CentOS-Base.repo
else
    wget http://mirrors.163.com/.help/CentOS6-Base-163.repo
    mv CentOS6-Base-163.repo  /etc/yum.repos.d/CentOS-Base.repo
fi
yum clean all
yum makecache
 
#更改ulimit参数
if [ "`cat/etc/security/limits.conf | grep 'soft nproc 65535'`" = "" ];then
cat  >> /etc/security/limits.conf <<EOF
* soft nproc 65535
* hard nproc 65535
* soft nofile 65535
* hard nofile 65535
EOF
echo "ulimit -SHn65535" >> /etc/profile
echo "ulimit -SHn65535" >> /etc/rc.local
fi
 
#安装必要工具
yum update -y
yum install -y vim wgetntpdate sysstat wget man mtr lsof iotop net-tools openssl-devel openssl-perliostat subversion nscd
 
#关闭selinux
sed -i's/SELINUX=enforcing/SELINUX=disabled/g' /etc/selinux/config
setenforce 0
 
#设置ssh
sed -i "s/\#UseDNSyes/UseDNS no/g" /etc/ssh/sshd_config
sed -i"s/GSSAPIAuthentication yes/GSSAPIAuthentication no/g"/etc/ssh/sshd_config
 
#设置时区
if [ "`cat/etc/crontab | grep ntpdate`" = "" ]; then
echo "0 23 * * *root /usr/sbin/ntpdate cn.pool.ntp.org >> /var/log/ntpdate.log">> /etc/crontab
fi
rm -f /etc/localtime
ln -s/usr/share/zoneinfo/Asia/Shanghai /etc/localtime
ntpdatecn.pool.ntp.org;hwclock -w
 
 
#设置sysctl
SYSCONF="
#Add
net.ipv4.tcp_max_syn_backlog= 65536
net.core.netdev_max_backlog=  32768
net.core.somaxconn =32768
 
net.core.wmem_default =8388608
net.core.rmem_default =8388608
net.core.rmem_max =16777216
net.core.wmem_max =16777216
net.ipv4.tcp_timestamps= 0
net.ipv4.tcp_synack_retries= 2
net.ipv4.tcp_syn_retries= 2
 
net.ipv4.tcp_tw_recycle= 1
#net.ipv4.tcp_tw_len =1
net.ipv4.tcp_tw_reuse =1
 
net.ipv4.tcp_mem =94500000 915000000 927000000
net.ipv4.tcp_max_orphans= 3276800
 
net.ipv4.tcp_fin_timeout= 120
net.ipv4.tcp_keepalive_time= 120
net.ipv4.ip_local_port_range= 1024  65535
 
net.nf_conntrack_max =16404388
net.netfilter.nf_conntrack_tcp_timeout_established= 10800
 
#kernel: TCP: time waitbucket table overflow
net.ipv4.tcp_max_tw_buckets= 30000
 
fs.file-max=655350"
 
#"安装系统工具"
yum install -y gccgcc-c++ make cmake autoconf bzip2 bzip2-devel curl openssl openssl-devel rsyncgd zip perl unzip
 
#重启服务
#ssh
if ["$VERSION" == "centos6" ]; then
    service sshd restart
    service iptables stop
    chkconfig iptables off
    if [ "`cat /etc/sysctl.conf | grepnet.ipv4.tcp_max_tw_buckets`" = "" ]; then
        echo "$SYSCONF" >>/etc/sysctl.conf    
    fi
    /sbin/sysctl -p
else
    systemctl restart sshd
    systemclt disable postfix.service
    systemctl stop postfix.service
    systemctl stop firewalld
    systemctl mask firewalld
    yum install iptables-services -y
    if [ ! -f '/etc/sysctl.d/addsys.conf'];then
        echo "$SYSCONF" >>/etc/sysctl.d/addsys.conf 
    fi 
    /sbin/sysctl -p
fi