suse 12 编译部署Keepalived + nginx 为 kube-apiserver 提供高可用

• suse 12 二进制部署 Kubernetes 集群系列合集：
  • suse 12 二进制部署 Kubernetets 1.19.7 - 第00章 - 环境准备
  • suse 12 二进制部署 Kubernetets 1.19.7 - 第01章 - 创建CA证书和kubectl集群管理命令
  • suse 12 二进制部署 Kubernetets 1.19.7 - 第02章 - 部署etcd集群
  • suse 12 二进制部署 Kubernetets 1.19.7 - 第03章 - 部署flannel插件
  • suse 12 二进制部署 Kubernetets 1.19.7 - 第04章 - 部署docker服务
  • suse 12 二进制部署 Kubernetets 1.19.7 - 第05章 - 部署kube-nginx
  • suse 12 二进制部署 Kubernetets 1.19.7 - 第06章 - 部署kube-apiserver组件
  • suse 12 二进制部署 Kubernetets 1.19.7 - 第07章 - 部署kube-controller-manager组件
  • suse 12 二进制部署 Kubernetets 1.19.7 - 第08章 - 部署kube-scheduler组件
  • suse 12 二进制部署 Kubernetets 1.19.7 - 第09章 - 部署kubelet组件
  • suse 12 二进制部署 Kubernetets 1.19.7 - 第10章 - 部署kube-proxy组件
  • suse 12 二进制部署 Kubernetets 1.19.7 - 第11章 - 部署coredns组件
  • suse 12 二进制部署 Kubernetets 1.19.7 - 第12章 - 部署dashboard插件
  • suse 12 二进制部署 Kubernetets 1.19.7 - 第13章 - 部署metrics-server插件
  • suse 12 编译部署Keepalived + nginx 为 kube-apiserver 提供高可用
  • suse 12 二进制部署 Kubernetets 1.19.7 - 番外篇 - 增加node节点

IP	SERVICES
192.168.72.55	keepalived+nginx
192.168.72.56	keepalived+nginx
192.168.72.57	keepalived+nginx
192.168.72.100	VIP

• 如果需要给kube-apiserver提供高可用，建议在部署kubernetes集群的时候就预先部署好keepalived+nginx，
  • 否则的话，需要修改kube-apiserver的证书，将vip加入到证书内，
  • 并且修改kube-config相关的秘钥（kube-controller、kube-scheduler、kubelet、kube-proxy）都需要重新生成，将原有的kube-apiserver的认证地址修改为VIP
  • 重启kube-apiserver、kube-controller、kube-scheduler、kubelet、kube-proxy服务，最终就可以实现高可用
  • 所以，在kubernetes集群部署前先完成keepalived+nginx就会方便很多
• 为什么选择keepalived？
  • 因为keepalived有后端服务健康检测机制，检测到后端的nginx（nginx为了使用upstream模块实现负载均衡）服务有故障，就会将自己（keepalived）关闭，使VIP漂移到另外两个节点中的一个，用来保证和实现kube-apiserver服务的高可用
• 此次部署，是基于了我博客前面的 suse 12 二进制部署 Kubernetets 1.19.7系列，最后的分发脚本和启动服务里面的数组需要自行修改(修改成自己的ip或者主机名即可，主机名需要提前做好hosts解析)

编译部署nginx

下载nginx源码包

k8s-01:~ # cd /opt/k8s/packages/
k8s-01:/opt/k8s/packages # wget http://nginx.org/download/nginx-1.16.1.tar.gz
k8s-01:/opt/k8s/packages # tar xf nginx-1.16.1.tar.gz

编译nginx

k8s-01:~ # cd /opt/k8s/packages/nginx-1.16.1/
k8s-01:/opt/k8s/packages/nginx-1.16.1 # ./configure --prefix=$(pwd)/nginx-prefix \
--with-stream \
--without-http \
--without-http_uwsgi_module && \
make && \
make install

配置nginx.conf

k8s-01:~ # cd /opt/k8s/conf/
k8s-01:/opt/k8s/conf # cat > kube-nginx.conf <<EOF
worker_processes 1;
events {
    worker_connections  1024;
}
stream {
    upstream backend {
        hash \$remote_addr consistent;
        server 192.168.72.55:6443        max_fails=3 fail_timeout=30s;
        server 192.168.72.56:6443        max_fails=3 fail_timeout=30s;
        server 192.168.72.57:6443        max_fails=3 fail_timeout=30s;
    }
    server {
        listen *:8443;
        proxy_connect_timeout 1s;
        proxy_pass backend;
    }
}
EOF

配置nginx为systemctl管理

k8s-01:~ # cd /opt/k8s/conf/
k8s-01:/opt/k8s/conf # cat > kube-nginx.service <<EOF
[Unit]
Description=kube-apiserver nginx proxy
After=network.target
After=network-online.target
Wants=network-online.target
[Service]
Type=forking
ExecStartPre=/opt/k8s/server/kube-nginx/sbin/nginx \
          -c /opt/k8s/server/kube-nginx/conf/kube-nginx.conf \
          -p /opt/k8s/server/kube-nginx -t
ExecStart=/opt/k8s/server/kube-nginx/sbin/nginx \
       -c /opt/k8s/server/kube-nginx/conf/kube-nginx.conf \
       -p /opt/k8s/server/kube-nginx
ExecReload=/opt/k8s/server/kube-nginx/sbin/nginx \
        -c /opt/k8s/server/kube-nginx/conf/kube-nginx.conf \
        -p /opt/k8s/server/kube-nginx -s reload
PrivateTmp=true
Restart=always
RestartSec=5
StartLimitInterval=0
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
EOF

分发nginx二进制文件和配置文件

#!/usr/bin/env bash
source /opt/k8s/bin/k8s-env.sh

for host in ${MASTER_IPS[@]}
do
    printf "\e[1;34m${host}\e[0m\n"
    ssh root@${host} "mkdir -p /opt/k8s/server/kube-nginx/{conf,logs,sbin}"
    scp /opt/k8s/packages/nginx-1.16.1/nginx-prefix/sbin/nginx ${host}:/opt/k8s/server/kube-nginx/sbin/
    scp /opt/k8s/conf/kube-nginx.conf ${host}:/opt/k8s/server/kube-nginx/conf/
    scp /opt/k8s/conf/kube-nginx.service ${host}:/etc/systemd/system/
done

启动kube-nginx服务

#!/usr/bin/env bash
source /opt/k8s/bin/k8s-env.sh

for host in ${MASTER_IPS[@]}
do
    printf "\e[1;34m${host}\e[0m\n"
    ssh root@${host} "systemctl daemon-reload && \
                      systemctl enable kube-nginx --now && \
                      systemctl status kube-nginx | grep Active"
done

编译部署keepalived

下载keepalived源码包

k8s-01:~ # cd /opt/k8s/packages/
k8s-01:/opt/k8s/packages # wget https://www.keepalived.org/software/keepalived-2.2.0.tar.gz
k8s-01:/opt/k8s/packages # tar xf keepalived-2.2.0.tar.gz

编译keepalived

k8s-01:/opt/k8s/packages/keepalived-2.2.0 # ./configure --prefix=$(pwd)/keepalived-prefix && \
make && \
make install

配置keepalived.conf

k8s-01:~ # cd /opt/k8s/conf/
k8s-01:/opt/k8s/conf # cat > keepalived.conf.template <<EOF
! Configuration File for keepalived
global_defs {
}
vrrp_script chk_nginx {
    script "/etc/keepalived/check_port.sh 8443"
    interval 2
    weight -20
}
vrrp_instance VI_1 {
    state BACKUP
    interface eth0
    virtual_router_id 251
    priority 100
    advert_int 1
    mcast_src_ip ##NODE_IP##
    nopreempt
    authentication {
        auth_type PASS
        auth_pass 11111111
    }
    track_script {
         chk_nginx
    }
    virtual_ipaddress {
        192.168.72.100
    }
}
EOF

• 为了避免keepalived服务出现问题，修复后重启keepalived，出现IP漂移回来的情况，这里选择了3个都是BACKUP的模式，减少数据的丢失

创建健康检测脚本

k8s-01:~ # cd /opt/k8s/conf/
k8s-01:/opt/k8s/conf # cat > check_port.sh <<"EOF"
CHK_PORT=$1
 if [ -n "$CHK_PORT" ];then
        PORT_PROCESS=$(ss -lt|grep $CHK_PORT|wc -l)
        if [ $PORT_PROCESS -eq 0 ];then
                echo "Port $CHK_PORT Is Not Used,End."
                exit 1
        fi
 else
        echo "Check Port Cant Be Empty!"
 fi
EOF

配置keepalived为systemctl管理

k8s-01:~ # cd /opt/k8s/conf/
k8s-01:/opt/k8s/conf # cat > keepalived.service <<EOF
[Unit]
Description=LVS and VRRP High Availability Monitor
After=syslog.target network-online.target

[Service]
Type=forking
PIDFile=/var/run/keepalived.pid
KillMode=process
EnvironmentFile=-/etc/sysconfig/keepalived
ExecStart=/usr/sbin/keepalived \$KEEPALIVED_OPTIONS
ExecReload=/bin/kill -HUP \$MAINPID

[Install]
WantedBy=multi-user.target
EOF

分发keepalived二进制文件和配置文件

#!/usr/bin/env bash
source /opt/k8s/bin/k8s-env.sh

for (( i=0; i < 3; i++ ))
do
    sed -e "s/##NODE_IP##/${MASTER_IPS[i]}/" /opt/k8s/conf/keepalived.conf.template > \
           /opt/k8s/conf/keepalived.conf-${MASTER_IPS[i]}.template
done

for host in ${MASTER_IPS[@]}
do
    printf "\e[1;34m${host}\e[0m\n"
    ssh root@${host} "mkdir -p /etc/keepalived"
    scp /opt/k8s/packages/keepalived-2.2.0/keepalived-prefix/sbin/keepalived ${host}:/usr/sbin/
    scp /opt/k8s/packages/keepalived-2.2.0/keepalived-prefix/etc/sysconfig/keepalived ${host}:/etc/sysconfig/
    scp /opt/k8s/conf/keepalived.conf-${host}.template ${host}:/etc/keepalived/keepalived.conf
    scp /opt/k8s/conf/check_port.sh ${host}:/etc/keepalived/
    scp /opt/k8s/conf/keepalived.service ${host}:/etc/systemd/system/
done

for host in ${MASTER_IPS[@]}
do
    printf "\e[1;34m${host}\e[0m\n"
    ssh root@${host} "systemctl daemon-reload && \
                      systemctl enable keepalived --now && \
                      systemctl status keepalived | grep Active"
done

查看VIP所在的机器以及是否ping通

#!/usr/bin/env bash
source /opt/k8s/bin/k8s-env.sh

for host in ${MASTER_IPS[@]}
do
    printf "\e[1;34m${host}\e[0m\n"
    ssh root@${host} "ip a | grep 192.168.72.100"
done

ping 192.168.72.100 -c 1