centos系统优化shell

#!/bin/bash

#Cenetos6/7初始化脚本
# get os version
RELEASEVER=(rpm−q−−qf"(rpm−q−−qf"(rpm -q --whatprovides redhat-release))

# configure yum source
cd /etc/yum.repos.d/
mkdir /etc/yum.repos.d/bak
mv /etc/yum.repos.d/*.repo /etc/yum.repos.d/bak
if [ RELEASEVER==6];thencurlhttp://mirrors.163.com/.help/CentOS6−Base−163.repo>qf.repofiif[RELEASEVER==6];thencurlhttp://mirrors.163.com/.help/CentOS6−Base−163.repo>qf.repofiif[RELEASEVER == 7 ];then
    curl http://mirrors.163.com/.help/CentOS7-Base-163.repo > qf.repo
fi
yum clean all
yum check-update

# install base rpm package
yum -y install epel-release
yum -y install nc vim iftop iotop dstat tcpdump
yum -y install ipmitool bind-libs bind-utils
yum -y install libselinux-python ntpdate

# update rpm package include kernel
yum -y update
rm -rf /etc/yum.repos.d/CentOS*

# update ulimit configure
if [ RELEASEVER == 6 ];then     test -f /etc/security/limits.d/90-nproc.conf && rm -rf /etc/security/limits.d/90-nproc.conf && touch /etc/security/limits.d/90-nproc.conf fi if [RELEASEVER == 6 ];then     test -f /etc/security/limits.d/90-nproc.conf && rm -rf /etc/security/limits.d/90-nproc.conf && touch /etc/security/limits.d/90-nproc.conf fi if [RELEASEVER == 7 ];then
    test -f /etc/security/limits.d/20-nproc.conf && rm -rf /etc/security/limits.d/20-nproc.conf && touch /etc/security/limits.d/20-nproc.conf
fi

> /etc/security/limits.conf
cat >> /etc/security/limits.conf <<EOF
* soft nproc 65535
* hard nproc 65535
* soft nofile 65535
* hard nofile 65535
EOF

# set timezone
test -f /etc/localtime && rm -rf /etc/localtime
ln -s /usr/share/zoneinfo/Asia/Shanghai /etc/localtime

# set LANG
if [ RELEASEVER==6];thensed−i′s@LANG=.∗RELEASEVER==6];thensed−i′s@LANG=.∗@LANG="en_US.UTF-8"@g' /etc/sysconfig/i18n
fi
if [ RELEASEVER==7];thensed−i′s@LANG=.∗RELEASEVER==7];thensed−i′s@LANG=.∗@LANG="en_US.UTF-8"@g' /etc/locale.conf
fi

# update time
if [ RELEASEVER==6];then/usr/sbin/ntpdate−bpool.ntp.orggrep−qntpdate/var/spool/cron/rootif[RELEASEVER==6];then/usr/sbin/ntpdate−bpool.ntp.orggrep−qntpdate/var/spool/cron/rootif[? -ne 0 ]; then
        echo '* * * * * /usr/sbin/ntpdate pool.ntp.org > /dev/null 2>&1' > /var/spool/cron/root;chmod 600 /var/spool/cron/root
    fi
    /etc/init.d/crond restart
fi

if [ $RELEASEVER == 7 ];then
    yum -y install chrony
    > /etc/chrony.conf
cat > /etc/chrony.conf << EOF
server pool.ntp.org iburst
stratumweight 0
driftfile /var/lib/chrony/drift
rtcsync
makestep 10 3
bindcmdaddress 127.0.0.1
bindcmdaddress ::1
keyfile /etc/chrony.keys
commandkey 1
generatecommandkey
noclientlog
logchange 0.5
logdir /var/log/chrony
EOF

systemctl restart chronyd
systemctl enable chronyd
fi

# clean iptables default rules
if [ RELEASEVER==6];then/sbin/iptables−Fserviceiptablessavechkconfigiptablesofffiif[RELEASEVER==6];then/sbin/iptables−Fserviceiptablessavechkconfigiptablesofffiif[RELEASEVER == 7 ];then
    systemctl disable firewalld
fi

# disable unused service
chkconfig auditd off

# disable ipv6
cd /etc/modprobe.d/ && touch ipv6.conf
> /etc/modprobe.d/ipv6.conf
cat >> /etc/modprobe.d/ipv6.conf << EOF
alias net-pf-10 off
alias ipv6 off
EOF

# disable iptable nat moudule
cd /etc/modprobe.d/ && touch connectiontracking.conf
> /etc/modprobe.d/connectiontracking.conf
cat >> /etc/modprobe.d/connectiontracking.conf <<EOF
install nf_nat /bin/true
install xt_state  /bin/true
install iptable_nat /bin/true
install nf_conntrack /bin/true
install nf_defrag_ipv4   /bin/true
install nf_conntrack_ipv4 /bin/true
install nf_conntrack_ipv6  /bin/true
EOF

# disable SELINUX
setenforce 0
sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/selinux/config   # update record command sed -i 's/^HISTSIZE=.*/SELINUX=disabled/' /etc/selinux/config   # update record command sed -i 's/^HISTSIZE=.*/HISTSIZE=100000/' /etc/profile
grep -q 'HISTTIMEFORMAT' /etc/profile
if [[ ?−eq0]];thensed−i′s/HISTTIMEFORMAT=.∗?−eq0]];thensed−i′s/HISTTIMEFORMAT=.∗/HISTTIMEFORMAT="%F %T "/' /etc/profile
else
echo 'HISTTIMEFORMAT="%F %T "' >> /etc/profile
fi

# install dsnmasq and update configure //本地dns查询缓存
yum -y install dnsmasq
> /etc/dnsmasq.conf
cat >> /etc/dnsmasq.conf<< EOF
listen-address=127.0.0.1
no-dhcp-interface=lo
log-queries
log-facility=/var/log/dnsmasq.log
all-servers
no-negcache
cache-size=1024
dns-forward-max=512
EOF

if [ $RELEASEVER == 6 ];then
    /etc/init.d/dnsmasq restart
fi

if [ $RELEASEVER == 7 ];then
    systemctl restart dnsmasq
systemctl enable dnsmasq
fi

# update /etc/resolv.conf
> /etc/resolv.conf
cat >> /etc/resolv.conf<< EOF
options timeout:1
nameserver 127.0.0.1
nameserver 114.114.114.114
EOF

# update /etc/sysctl.conf
cat >> /etc/sysctl.conf<< EOF
net.ipv4.tcp_syncookies = 1
kernel.core_uses_pid=1
kernel.core_pattern=/tmp/core-%e-%p
fs.suid_dumpable=2
net.ipv4.tcp_tw_reuse=1
net.ipv4.tcp_tw_recycle=0
net.ipv4.tcp_timestamps=1
EOF
sysctl -p