centos7初始化.sh

#!/bin/bash
yum install -y wget vim 
if [[ "$(whoami)" != "root" ]]; then
  
    echo "please run this script as root ." >&2
    exit 1
fi
  
echo -e "\033[31m 这个是centos7系统初始化脚本，请慎重运行！Please continue to enter or ctrl+C to cancel \033[0m"
sleep 5

#configure yum source
yum_config(){
    yum install wget epel-release -y
    cd /etc/yum.repos.d/ && mkdir bak && mv -f *.repo bak/
    wget -O /etc/yum.repos.d/CentOS-Base.repo http://mirrors.aliyun.com/repo/Centos-7.repo
    wget -O /etc/yum.repos.d/epel.repo http://mirrors.aliyun.com/repo/epel-7.repo
    yum clean all && yum makecache
    yum -y install iotop iftop net-tools lrzsz gcc gcc-c++ make cmake libxml2-devel openssl-devel curl curl-devel unzip sudo ntp libaio-devel wget vim ncurses-devel autoconf automake zlib-devel  python-devel bash-completion
	yum -y update
}
#firewalld
iptables_config(){
    systemctl stop firewalld.service
    systemctl disable firewalld.service
    yum install iptables-services -y
    systemctl enable iptables
    systemctl start iptables
    iptables -F
    service iptables save
}
#system config
system_config(){
    sed -i "s/SELINUX=enforcing/SELINUX=disabled/g" /etc/selinux/config
    timedatectl set-local-rtc 1 && timedatectl set-timezone Asia/Shanghai
    yum -y install chrony && systemctl start chronyd.service && systemctl enable chronyd.service
	systemctl stop NetworkManager && systemctl disabled NetworkManager
	echo "system_config is ok"
}
ulimit_config(){
    echo "ulimit -SHn 102400" >> /etc/rc.local
    cat >> /etc/security/limits.conf << EOF
    *           soft   nofile       102400
    *           hard   nofile       102400
    *           soft   nproc        102400
    *           hard   nproc        102400
EOF

}

#set sysctl
sysctl_config(){
    cp /etc/sysctl.conf /etc/sysctl.conf.bak
    cat > /etc/sysctl.conf << EOF
    net.ipv4.ip_forward = 0
    net.ipv4.conf.default.rp_filter = 1
    net.ipv4.conf.default.accept_source_route = 0
    kernel.sysrq = 0
    kernel.core_uses_pid = 1
    net.ipv4.tcp_syncookies = 1
    kernel.msgmnb = 65536
    kernel.msgmax = 65536
    kernel.shmmax = 68719476736
    kernel.shmall = 4294967296
    net.ipv4.tcp_max_tw_buckets = 6000
    net.ipv4.tcp_sack = 1
    net.ipv4.tcp_window_scaling = 1
    net.ipv4.tcp_rmem = 4096 87380 4194304
    net.ipv4.tcp_wmem = 4096 16384 4194304
    net.core.wmem_default = 8388608
    net.core.rmem_default = 8388608
    net.core.rmem_max = 16777216
    net.core.wmem_max = 16777216
    net.core.netdev_max_backlog = 262144
    net.core.somaxconn = 262144
    net.ipv4.tcp_max_orphans = 3276800
    net.ipv4.tcp_max_syn_backlog = 262144
    net.ipv4.tcp_timestamps = 0
    net.ipv4.tcp_synack_retries = 1
    net.ipv4.tcp_syn_retries = 1
    net.ipv4.tcp_tw_recycle = 1
    net.ipv4.tcp_tw_reuse = 1
    net.ipv4.tcp_mem = 94500000 915000000 927000000
    net.ipv4.tcp_fin_timeout = 1
    net.ipv4.tcp_keepalive_time = 30
    net.ipv4.ip_local_port_range = 1024 65000
EOF
    /sbin/sysctl -p
    echo "sysctl set OK!!"
}

#change ssh port
ssh_port() {
	sed -ri '17aPort 4983' /etc/ssh/sshd_config
	systemctl restart sshd
	echo "ssh port was changed"
}

main(){
    yum_config
    system_config
    ulimit_config
    sysctl_config
	ssh_port
}
main