centos环境配置

centos环境配置

centos7基础环境

yum install -y vim ntp rsync
yum install -y telnet bind-utils sysstat net-tools

limit 修改线程数限制

grep -q 'docker' /etc/security/limits.conf 
if [ $? -ne 0 ];then
tee -a /etc/security/limits.conf << EOF
root   -  nofile  40960
nginx  -  nofile  40960
apache -  nofile  40960
www    -  nofile  40960
service - nofile  40960
docker  - nofile  40960
EOF
fi

DNS

cat > /etc/resolv.conf << EOF
options timeout:1 attempts:1
nameserver 10.10.25.4
nameserver 114.114.114.114
EOF

时间同步

yum install ntp -y
ntpdate time-server.boss.com
sed -i 's/^server 0.centos.pool.ntp.org iburst/server time-server.boss.com/' /etc/ntp.conf
systemctl start ntpd
systemctl enable ntpd

加上本机 hosts 解析

host_name=`hostname`
host_ip=$(ip addr |grep inet | egrep -v 'inet6|docker|br-|127.0.0.1|lo:' | awk '/^[0-9]+: / {}; /inet.*global/ {print gensub(/(.*)\/(.*)/, "\\1", "g", $2)}' | head -n 1)
grep $host_name /etc/hosts || echo '' >> /etc/hosts && echo "${host_ip} ${host_name}" >> /etc/hosts

TCP优化

grep -q 'tcp_fin_timeout' /etc/sysctl.conf
if [ $? -ne 0 ];then
tee -a /etc/sysctl.conf <<-EOF
net.ipv4.tcp_fin_timeout = 30
EOF
sysctl -p
fi