二进制安装kubernetes v1.11.2 （第七章 部署高可用组件）

继续上一章部署。

八、部署高可用组件

本章介绍keepalived和haproxy实现kube-apiserver高可用。

• keepalive 提供 kube-apiserver 对外提供服务的VIP；
• haproxy 监听VIP，后端链接所有 kube-apiserver 实例，提供健康检查和负载均衡功能
• keepalived 一主一备的运行模式，本文档复用 master 节点的两台设备
• haproxy 监听 8443 端口，与 kube-apiserver 的 6443 端口区分开
• keepalived 在运行过程中周期检查本机的 haproxy 进程状态，如果检测到 haproxy 进程异常，则触发重新选主的过程，将VIP飘逸到新选出来的主节点，从而实现 VIP 的高可用
• 所有组件都通过 VIP 和 haproxy 监听的 8443 端口访问 kube-apiserver

8.1 安装软件包

source /opt/k8s/bin/environment.sh
for master_ip in ${MASTER_IPS[@]}
  do
    echo ">>> ${master_ip}"
    ssh [email protected]${master_ip} "sudo yum install -y keepalived haproxy"
done

8.2 配置 haproxy

cat > haproxy.cfg <<EOF
global
    log /dev/log    local0
    log /dev/log    local1 notice
    chroot /var/lib/haproxy
    stats socket /var/run/haproxy-admin.sock mode 660 level admin
    stats timeout 30s
    user haproxy
    group haproxy
    daemon
    nbproc 1

defaults
    log     global
    timeout connect 5000
    timeout client  10m
    timeout server  10m

listen  admin_stats
    bind 0.0.0.0:10080
    mode http
    log 127.0.0.1 local0 err
    stats refresh 30s
    stats uri /status
    stats realm welcome login\ Haproxy
    stats auth admin:123456
    stats hide-version
    stats admin if TRUE

listen kube-master
    bind 0.0.0.0:8443
    mode tcp
    option tcplog
    balance source
    server 192.168.56.20 192.168.56.20:6443 check inter 2000 fall 2 rise 2 weight 1
    server 192.168.56.21 192.168.56.21:6443 check inter 2000 fall 2 rise 2 weight 1
EOF

• haproxy 在10080端口输出 status 信息
• haproxy 监听所有接口的 8443 端口，该端口与环境变量 ${KUBE_APISERVER} 指定的端口必须一致
• server 字段列出所有 kube-apiserver 监听的 IP 和端口

8.3 下发 haproxy.cfg 到所有 master 节点

source /opt/k8s/bin/environment.sh
for master_ip in ${MASTER_IPS[@]}
  do
    echo ">>> ${master_ip}"
    scp haproxy.cfg [email protected]${master_ip}:/etc/haproxy
done

8.4 起 haproxy 服务

source /opt/k8s/bin/environment.sh
for master_ip in ${MASTER_IPS[@]}
  do
    echo ">>> ${master_ip}"
    ssh [email protected]${master_ip} "sudo systemctl restart haproxy"
done

8.5 检查服务状态

source /opt/k8s/bin/environment.sh
for master_ip in ${MASTER_IPS[@]}
  do
    echo ">>> ${master_ip}"
    ssh [email protected]${master_ip} "sudo systemctl status haproxy|grep Active"
done

确保状态都是 active (running)。

查看日志：journalctl -u haproxy

8.6 检查是否监听了 8443 端口

source /opt/k8s/bin/environment.sh
for master_ip in ${MASTER_IPS[@]}
  do
    echo ">>> ${master_ip}"
    ssh [email protected]${master_ip} "sudo netstat -lnpt|grep haproxy"
done

8.7 配置 keeplived

keepalived 是一主一备的运行模式，所以配置文件类型有两种

master 192.168.56.20
backup 192.168.56.21

master配置文件：

source /opt/k8s/bin/environment.sh
cat  > keepalived-master.conf <<EOF
global_defs {
    router_id lb-master-105
}

vrrp_script check-haproxy {
    script "killall -0 haproxy"
    interval 5
    weight -30
}

vrrp_instance VI-kube-master {
    state MASTER
    priority 120
    dont_track_primary
    interface ${VIP_IF}
    virtual_router_id 68
    advert_int 3
    track_script {
        check-haproxy
    }
    virtual_ipaddress {
        ${MASTER_VIP}
    }
}
EOF

• 两个地方需要注意 ${VIP_IF} 和 ${MASTER_VIP}
• 使用 killall -0 haproxy 命令检查所在节点的 haproxy 进程是否正常。如果异常则将权重减少（-30），从而触发重新选主的过程
• route_id、virtual_router_id 用于标识属于该 HA 的keepalived 实例，如果有多套keepalived HA，则必须各不相同

backup 配置文件：

source /opt/k8s/bin/environment.sh
cat  > keepalived-backup.conf <<EOF
global_defs {
    router_id lb-backup-105
}

vrrp_script check-haproxy {
    script "killall -0 haproxy"
    interval 5
    weight -30
}

vrrp_instance VI-kube-master {
    state BACKUP
    priority 110
    dont_track_primary
    interface ${VIP_IF}
    virtual_router_id 68
    advert_int 3
    track_script {
        check-haproxy
    }
    virtual_ipaddress {
        ${MASTER_VIP}
    }
}
EOF

• priority 的值必须小于 master

8.8 下发keepalived配置文件

[[email protected] ha_config]# scp keepalived-master.conf [email protected]192.168.56.20:/etc/keepalived/keepalived.conf
[[email protected]-m1 ha_config]# scp keepalived-backup.conf [email protected]192.168.56.21:/etc/keepalived/keepalived.conf

8.9 起 keepalived 服务

source /opt/k8s/bin/environment.sh
for master_ip in ${MASTER_IPS[@]}
  do
    echo ">>> ${master_ip}"
    ssh [email protected]${master_ip} "systemctl restart keepalived"
done

8.10 检查服务状态

# 确认服务是 active (running)
source /opt/k8s/bin/environment.sh
for master_ip in ${MASTER_IPS[@]}
  do
    echo ">>> ${master_ip}"
    ssh [email protected]${master_ip} "systemctl status keepalived|grep Active"
done

# 查看 VIP 所在的节点，确保可以 ping 通 VIP
source /opt/k8s/bin/environment.sh
for master_ip in ${MASTER_IPS[@]}
  do
    echo ">>> ${master_ip}"
    ssh [email protected]${master_ip} "/usr/sbin/ip addr show ${VIP_IF}"
    ssh [email protected]${master_ip} "ping -c 1 ${MASTER_VIP}"
done

# 查看日志 journalctl -u keepalived

8.11 浏览器打开status也没

地址：${MASTER_VIP}:10080/status

用户名和密码在 haproxy.cfg 的 status auth 字段

HAProxy status页面

原文地址：https://www.cnblogs.com/aast/p/9844068.html