kubernetes haproxy部署

06-1.部署高可用组件

本文档讲解使用 keepalived 和 haproxy 实现 kube-apiserver 高可用的步骤:

  • keepalived 提供 kube-apiserver 对外服务的 VIP;
  • haproxy 监听 VIP,后端连接所有 kube-apiserver 实例,提供健康检查和负载均衡功能;

运行 keepalived 和 haproxy 的节点称为 LB 节点。由于 keepalived 是一主多备运行模式,故至少两个 LB 节点。

本文档复用 master 节点的三台机器,haproxy 监听的端口(8443) 需要与 kube-apiserver 的端口 6443 不同,避免冲突。

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,VIP 将飘移到新选出来的主节点,从而实现 VIP 的高可用。

所有组件(如 kubeclt、apiserver、controller-manager、scheduler 等)都通过 VIP 和 haproxy 监听的 8443 端口访问 kube-apiserver 服务。

安装软件包

source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    ssh root@${node_ip} "yum install -y keepalived haproxy"
  done

配置和下发 haproxy 配置文件

haproxy 配置文件:

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 172.27.129.105 172.27.129.105:6443 check inter 2000 fall 2 rise 2 weight 1
    server 172.27.129.111 172.27.129.111:6443 check inter 2000 fall 2 rise 2 weight 1
    server 172.27.129.112 172.27.129.112:6443 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;

下发 haproxy.cfg 到所有 master 节点:

source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    scp haproxy.cfg root@${node_ip}:/etc/haproxy
  done

起 haproxy 服务

source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    ssh root@${node_ip} "systemctl restart haproxy"
  done

检查 haproxy 服务状态

source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    ssh root@${node_ip} "systemctl status haproxy|grep Active"
  done

确保状态为 active (running),否则查看日志,确认原因:

journalctl -u haproxy

检查 haproxy 是否监听 8443 端口:

source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    ssh root@${node_ip} "netstat -lnpt|grep haproxy"
  done

确保输出类似于:

tcp        0      0 0.0.0.0:8443            0.0.0.0:*               LISTEN      120583/haproxy

配置和下发 keepalived 配置文件

keepalived 是一主(master)多备(backup)运行模式,故有两种类型的配置文件。master 配置文件只有一份,backup 配置文件视节点数目而定,对于本文档而言,规划如下:

  • master: 172.27.129.105
  • backup:172.27.129.111、172.27.129.112

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
  • VIP 所在的接口(interface ${VIP_IF})为 eth0
  • 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),从而触发重新选主过程;
  • router_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
  • VIP 所在的接口(interface ${VIP_IF})为 eth0
  • 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),从而触发重新选主过程;
  • router_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;
  • priority 的值必须小于 master 的值;

下发 keepalived 配置文件

下发 master 配置文件:

scp keepalived-master.conf root@172.27.129.105:/etc/keepalived/keepalived.conf

下发 backup 配置文件:

scp keepalived-backup.conf root@172.27.129.111:/etc/keepalived/keepalived.conf
scp keepalived-backup.conf root@172.27.129.112:/etc/keepalived/keepalived.conf

起 keepalived 服务

source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    ssh root@${node_ip} "systemctl restart keepalived"
  done

检查 keepalived 服务

source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    ssh root@${node_ip} "systemctl status keepalived|grep Active"
  done

确保状态为 active (running),否则查看日志,确认原因:

journalctl -u keepalived

查看 VIP 所在的节点,确保可以 ping 通 VIP:

source /opt/k8s/bin/environment.sh
for node_ip in ${NODE_IPS[@]}
  do
    echo ">>> ${node_ip}"
    ssh ${node_ip} "/usr/sbin/ip addr show ${VIP_IF}"
    ssh ${node_ip} "ping -c 1 ${MASTER_VIP}"
  done

查看 haproxy 状态页面

浏览器访问 ${MASTER_VIP}:10080/status 地址,查看 haproxy 状态页面:

screenshot







发表于: 1月前   最后更新时间: 1月前   游览量:189
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