Linux系统优化

#!/bin/bash
# filename :linux_optimize.sh
#
#
export PATH=$PATH:/bin:/sbin:/usr/sbin
# Require root to run this script.
if [ "$UID" != "0" ]; then
echo "Please run this script by root."
exit 1
fi

#define cmd var
SERVICE=`which service`
CHKCONFIG=`which chkconfig`

function mod_yum(){
#modify yum path
if [ -e /etc/yum.repos.d/CentOS-Base.repo ]
then
mv /etc/yum.repos.d/CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo.backup&&
wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-6.repo
fi
}

function close_selinux(){
#1.close selinux
sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
#grep SELINUX=disabled /etc/selinux/config
setenforce 0 &>/dev/null
#getenforce
}

function close_iptables(){
#2.close iptables
/etc/init.d/iptables stop
/etc/init.d/iptables stop
chkconfig iptables off
}

function least_service(){
#3.least service startup
chkconfig|awk '{print "chkconfig",$1,"off"}'|bash
chkconfig|egrep "crond|sshd|network|rsyslog|sysstat"|awk '{print "chkconfig",$1,"on"}'|bash
#export LANG=en
#chkconfig --list|grep 3:on
}

function adduser(){
#4.add oldboy and sudo
if [ `grep -w oldboy /etc/passwd|wc -l` -lt 1 ]
then
useradd oldboy
echo 123456|passwd --stdin oldboy
cp /etc/sudoers /etc/sudoers.ori
echo "oldboy ALL=(ALL) NOPASSWD: ALL " >>/etc/sudoers
tail -1 /etc/sudoers
visudo -c &>/dev/null
fi
}

function charset(){
#5.charset config
cp /etc/sysconfig/i18n /etc/sysconfig/i18n.ori
echo 'LANG="zh_CN.UTF-8"' >/etc/sysconfig/i18n
source /etc/sysconfig/i18n
#echo $LANG
}

function time_sync(){
#6.time sync.
cron=/var/spool/cron/root
if [ `grep -w "ntpdate" $cron|wc -l` -lt 1 ]
then
echo '#time sync by oldboy at 2010-2-1' >>$cron
echo '*/5 * * * * /usr/sbin/ntpdate time.nist.gov >/dev/null 2>&1' >>$cron
crontab -l
fi
}

function com_line_set(){
#7.command set.
if [ `egrep "TMOUT|HISTSIZE|HISTFILESIZE" /etc/profile|wc -l` -ge 3 ]
then
echo 'export TMOUT=300' >>/etc/profile
echo 'export HISTSIZE=5' >>/etc/profile
echo 'export HISTFILESIZE=5' >>/etc/profile
. /etc/profile
fi
}

function open_file_set(){
#8.increase open file.
if [ `grep 65535 /etc/security/limits.conf|wc -l` -lt 1 ]
then
echo '* - nofile 65535 ' >>/etc/security/limits.conf
tail -1 /etc/security/limits.conf
fi
}

function set_kernel(){
#9.kernel set.
if [ `grep kernel_flag /etc/sysctl.conf|wc -l` -lt 1 ]
then
cat >>/etc/sysctl.conf<<EOF
#kernel_flag
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 = 1
net.core.somaxconn = 16384
net.core.netdev_max_backlog = 16384
net.ipv4.tcp_max_orphans = 16384
net.nf_conntrack_max = 25000000
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
fi
}
function init_ssh(){
cp /etc/ssh/sshd_config /etc/ssh/sshd_config.`date +"%Y-%m-%d_%H-%M-%S"`
#sed -i 's%#Port 22%Port 52113%' /etc/ssh/sshd_config
sed -i 's%#PermitRootLogin yes%PermitRootLogin no%' /etc/ssh/sshd_config
sed -i 's%#PermitEmptyPasswords no%PermitEmptyPasswords no%' /etc/ssh/sshd_config
sed -i 's%#UseDNS yes%UseDNS no%' /etc/ssh/sshd_config
/etc/init.d/sshd reload &>/dev/null
}

function update_linux(){
#10.upgrade linux.
if [ `rpm -qa lrzsz nmap tree dos2unix nc|wc -l` -le 3 ]
then
yum install lrzsz nmap tree dos2unix nc -y
#yum update -y
fi
}
main(){
mod_yum
close_selinux
close_iptables
least_service
adduser
charset
time_sync
com_line_set
open_file_set
set_kernel
init_ssh
update_linux
}
main

#!/bin/bash
# filename : check_linux_optimize.sh

#set env
export PATH=$PATH:/bin:/sbin:/usr/sbin
# Require root to run this script.
if [ "$UID" != "0" ]; then
echo "Please run this script by root."
exit 1
fi

# Source function library.
. /etc/init.d/functions

function check_yum(){
Base=/etc/yum.repos.d/CentOS-Base.repo
if [ `grep aliyun $Base|wc -l` -ge 1 ];then
action "$Base config" /bin/true
else
action "$Base config" /bin/false
fi
}

function check_selinux(){
config=/etc/selinux/config
if [ `grep "SELINUX=disabled" $config|wc -l ` -ge 1 ];then
action "$config config" /bin/true
else
action "$config config" /bin/false
fi
}

function check_service(){
export LANG=en
if [ `chkconfig|grep 3:on|egrep "crond|sshd|network|rsyslog|sysstat"|wc -l` -eq 5 ]
then
action "sys service init" /bin/true
else
action "sys service init" /bin/false
fi
}
function check_open_file(){
limits=/etc/security/limits.conf
if [ `grep 65535 $limits|wc -l` -eq 1 ]
then
action "$limits" /bin/true
else
action "$limits" /bin/false
fi
}
main(){
check_yum
check_selinux
check_service
check_open_file
}
main