部署 HA 环境

部署高可用负载均衡集群

在部署生产可用的 kubernetes 集群之前，需要先部署 LoadBalancer 环境，这里使用 keepalived + haproxy 的方式实现负载均衡和高可用。

环境说明

单独拿两个节点部署 keepalived 和 haproxy 作为后端 kubernetes 控制平面的负载均衡器，拓扑结构如下:

两个节点上面分别部署 keepalived 和 haproxy 组成负载均衡集群，haproxy 的 backend 为后端的 kubernetes control plane node，vip(虚ip) 在这两个节点之间漂移形成高可用。

另外 Cloudpods 服务使用 Mariadb，如果没有专门的数据库集群，可以单独拿两个节点部署 Mariadb 高可用。参考 部署 DB HA 环境 。

部署

keepalived 的主要作用是为 haproxy 提供 vip，在2个 haproxy 实例之间提供主备，降低当其中一个haproxy失效的时对服务的影响。

部署配置 keepalived

设置相关的环境变量，根据不同的环境自行配置。

# keepalived vip 地址
export K8SHA_VIP=10.168.222.18

# keepalived auth toke
export K8SHA_KA_AUTH=412f7dc3bfed32194d1600c483e10ad1d

# keepalived network interface
export K8SHA_NETIF=eth0

设置 sysctl 选项

$ cat <<EOF >>/etc/sysctl.conf
net.ipv4.ip_forward = 1
net.ipv4.ip_nonlocal_bind = 1
EOF

$ sysctl -p

安装 keepalived

$ yum install -y keepalived

添加配置

$ cat <<EOF >/etc/keepalived/keepalived.conf
! Configuration File for keepalived

global_defs {
    router_id LVS_DEVEL
}

vrrp_script check_haproxy {
    script "pidof haproxy"
    interval 3
    weight -2
    fall 10
    rise 2
}

vrrp_instance VI_1 {
    state MASTER
    interface $K8SHA_NETIF
    virtual_router_id 51
    priority 250
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass $K8SHA_KA_AUTH
    }
    virtual_ipaddress {
        $K8SHA_VIP
    }
    track_script {
        check_haproxy
    }
}
EOF

启动 keepalived

$ systemctl enable --now keepalived
$ ip addr show $K8SHA_NETIF
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000
    link/ether 00:22:ff:95:87:f7 brd ff:ff:ff:ff:ff:ff
    inet 10.168.222.189/24 brd 10.168.222.255 scope global eth0
       valid_lft forever preferred_lft forever
    inet 10.168.222.18/32 scope global eth0
       valid_lft forever preferred_lft forever
    inet6 fe80::222:ffff:fe95:87f7/64 scope link
       valid_lft forever preferred_lft forever

部署配置 haproxy

此处的 haproxy 为 apiserver 提供反向代理，haproxy 将所有请求轮询转发到每个master节点上。

系统配置

export K8S_MASTER0=10.168.222.218
export K8S_MASTER1=10.168.222.197
export K8S_MASTER2=10.168.222.207

安装 haproxy

$ yum install -y haproxy

配置 haproxy

$ cat <<EOF >/etc/haproxy/haproxy.cfg
#---------------------------------------------------------------------
# Global settings
#---------------------------------------------------------------------
global
    # to have these messages end up in /var/log/haproxy.log you will
    # need to:
    #
    # 1) configure syslog to accept network log events.  This is done
    #    by adding the '-r' option to the SYSLOGD_OPTIONS in
    #    /etc/sysconfig/syslog
    #
    # 2) configure local2 events to go to the /var/log/haproxy.log
    #   file. A line like the following can be added to
    #   /etc/sysconfig/syslog
    #
    #    local2.*                       /var/log/haproxy.log
    #
    log         127.0.0.1 local2

    chroot      /var/lib/haproxy
    pidfile     /var/run/haproxy.pid
    maxconn     4000
    user        haproxy
    group       haproxy
    daemon

    # turn on stats unix socket
    stats socket /var/lib/haproxy/stats

#---------------------------------------------------------------------
# common defaults that all the 'listen' and 'backend' sections will
# use if not designated in their block
#---------------------------------------------------------------------
defaults
    mode                    http
    log                     global
    option                  httplog
    option                  dontlognull
    option http-server-close
    option forwardfor       except 127.0.0.0/8
    option                  redispatch
    retries                 3
    timeout http-request    10s
    timeout queue           1m
    timeout connect         10s
    timeout client          1m
    timeout server          1m
    timeout http-keep-alive 10s
    timeout check           10s
    maxconn                 3000

#---------------------------------------------------------------------
# kubernetes apiserver frontend which proxys to the backends
#---------------------------------------------------------------------
frontend kubernetes-apiserver
    mode                 tcp
    bind                 *:6443
    option               tcplog
    default_backend      kubernetes-apiserver

#---------------------------------------------------------------------
# round robin balancing between the various backends
#---------------------------------------------------------------------
backend kubernetes-apiserver
    mode        tcp
    balance     roundrobin
    server  master-0 $K8S_MASTER0:6443 check
    server  master-1 $K8S_MASTER1:6443 check
    server  master-2 $K8S_MASTER2:6443 check

#---------------------------------------------------------------------
# collection haproxy statistics message
#---------------------------------------------------------------------
listen stats
    bind                 *:1080
    stats auth           admin:awesomePassword
    stats refresh        5s
    stats realm          HAProxy\ Statistics
    stats uri            /admin?stats
EOF

启动并检测服务

$ systemctl enable haproxy.service --now
$ systemctl status haproxy.service
$ netstat -tulnp | egrep '6443|1080'
tcp        0      0 0.0.0.0:6443            0.0.0.0:*               LISTEN      10033/haproxy
tcp        0      0 0.0.0.0:1080            0.0.0.0:*               LISTEN      10033/haproxy

部署 kubernetes 集群

参考 部署集群 。


最后修改 13.04.2019