设置系统主机名以及 Host 文件的相互解析
    hostnamectl set-hostname k8s-master

    安装依赖包
    yum install -y conntrack ntpdate ntp ipvsadm ipset jq iptables curl sysstat libseccomp wgetvimnet-tools git

    设置防火墙为 Iptables 并设置空规则
    systemctl stop firewalld && systemctl disable firewalld
    yum -y install iptables-services && systemctl start iptables && systemctl enable iptables&& iptables -F && service iptables save

    关闭 SELINUX
    swapoff -a && sed -i ‘/ swap / s/^(.)$/#\1/g’ /etc/fstab
    setenforce 0 && sed -i ‘s/^SELINUX=.    /SELINUX=disabled/‘ /etc/selinux/config

    调整内核参数，对于 K8S
    cat > kubernetes.conf <net.bridge.bridge-nf-call-iptables=1
    net.bridge.bridge-nf-callip6tables=1
    net.ipv4.ip_forward=1
    net.ipv4.tcp_tw_recycle=0
    vm.swappiness=0 # 禁止使用 swap 空间，只有当系统 OOM 时才允许使用它
    m.overcommit_memory=1 # 不检查物理内存是否够用
    vm.panic_on_oom=0 # 开启
    OOMfs.inotify.max_user_instances=8192
    fs.inotify.max_user_watches=1048576
    fs.filemax=52706963
    s.nr_open=52706963
    net.ipv6.conf.all.disable_ipv6=1
    net.netfilter.nf_conntrack_max=2310720
    EOF

    cp kubernetes.conf /etc/sysctl.d/kubernetes.conf
    sysctl -p /etc/sysctl.d/kubernetes.conf

    调整系统时区
    timedatectl set-timezone Asia/Shanghai
    timedatectl set-local-rtc 0
    systemctl restart rsyslog
    systemctl restart crond

    关闭系统不需要服务
    systemctl stop postfix && systemctl disable postfix

    设置 rsyslogd 和 systemd journald
    mkdir /var/log/journal # 持久化保存日志的目录
    mkdir /etc/systemd/journald.conf.d

    cat > /etc/systemd/journald.conf.d/99-prophet.conf <[Journal]
    # 持久化保存到磁盘
    Storage=persistent
    # 压缩历史日志
    Compress=yes
    SyncIntervalSec=5m
    RateLimitInterval=30s
    RateLimitBurst=1000
    # 最大占用空间 10G
    SystemMaxUse=10G
    # 单日志文件最大 200M
    SystemMaxFileSize=200M
    # 日志保存时间 2 周
    MaxRetentionSec=2week
    # 不将日志转发到
    syslogForwardToSyslog=no
    EOF

    systemctl restart systemd-journald

    升级系统内核为 4.44
    rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm
    yum —enablerepo=elrepo-kernel install -y kernel-lt
    grub2-set-default ‘CentOS Linux (4.4.189-1.el7.elrepo.x86_64) 7 (Core)’
    reboot