部署环境

2台安装好Linux操作系统的主机,做为外置负载均衡集群单独部署，也可以运行静态的pod，以挂载卷的形式，挂载keepalived和haproxy的配置文件，即可运行一个Container进行负载均衡。本示例用单独主机负载。

部署配置先决条件

1. 2台已经安装好Linux操作系统的主机，本例以CentOS 7 为蓝本。
2. 配置好yum仓库，以便可直接安装相关负载均衡应用
3. 2台主机配置好网络，在同一个网段中，确保中间无防火墙，组播流量可正常发送与接收
4. 配置好时间同步
5. 关闭防火墙
6. 关闭SELinux
7. 两主机间通过hosts文件进行名称解析

角色解释

如上图所示，本示例安装两台单独的Linux主机做为负载均衡器，安装keepalived和haproxy。其中keepalived主要用于两台loadbalancer的主备切换，主要工作的是loadbalancer-1,而loadbalancer-2是闲置状态。haproxy用于向3台master进行用户的请求负载均衡。在本示例中，使用的是roundrobin的方式进行轮询的负载均衡。
本文主要介绍keepalived和haproxy的配置介绍。

部署步骤

一、安装软件

yum install keepalived haproxy -y

二、配置Keepalived

cp /etc/keepalived/keepalived.conf{,.backup}

2.1 配置Keepalived的Master的配置文件

! Configuration File for keepalived

global_defs {
   router_id Master
}

vrrp_script check_apiserver {
  script "/etc/keepalived/check_apiserver.sh"
  interval 3
  weight -2
  fall 10
  rise 2
}



vrrp_instance VI_1 {
    state MASTER
    interface ens192
    virtual_router_id 44
    priority 110
    advert_int 3
#    use_vmac
    authentication {
        auth_type PASS
        auth_pass PASSWORD
    }
    virtual_ipaddress {
        172.16.133.67
    }
    track_script {
        check_apiserver 
    }

}

2.2 配置Keepalived的BACKUP的配置文件

! Configuration File for keepalived

global_defs {
   router_id Backup
}

vrrp_script check_apiserver {
  script "/etc/keepalived/check_apiserver.sh"
  interval 3
  weight -2
  fall 10
  rise 2
}



vrrp_instance VI_1 {
    state BACKUP
    interface ens192
    virtual_router_id 44
    priority 105
    advert_int 3
#    use_vmac
    authentication {
        auth_type PASS
        auth_pass PASSWORD
    }
    virtual_ipaddress {
        172.16.133.67
    }
    track_script {
        check_apiserver 
    }

}

2.3 配置用于Keepalived的Kubernetes的健康检查配置文件(主备keepalived配置一样的脚本)

 vim /etc/keepalived/check_apiserver.sh 

#!/bin/bash

# 定义两个变量，用于定义APISERVER的ip地址，和端口
APISERVER_VIP="cluster-endpoint.microservice.for-best.cn" #域名要能够被DNS服务器解析，否则可以使用IP地址或者hosts文件解析
APISERVER_DEST_PORT=6443 # 默认端口为6443，如果端口不一样请一起改正

errorExit() {
    echo "*** $*" 1>&2
    exit 1
}

if ping -W 0.1  -c 3 -i 0.01 ${APISERVER_VIP} &> /dev/null; then
    curl --silent --max-time 2 --insecure https://${APISERVER_VIP}:${APISERVER_DEST_PORT}/ -o /dev/null || errorExit "Error GET https://${APISERVER_VIP}:${APISERVER_DEST_PORT}/"
fi

chmod +x check_apiserver.sh 

2.4 启动keepalived 并检查

systemctl start keepalived
systemctl enable keepalived --now

三、配置HAProxy

3.1 配置HAProxy的配置文件（2台主备服务器一样的配置）

#---------------------------------------------------------------------
# Global settings
#---------------------------------------------------------------------
global
    log /dev/log local0
    log /dev/log local1 notice
    daemon

#---------------------------------------------------------------------
# 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                 1
    timeout http-request    10s
    timeout queue           20s
    timeout connect         5s
    timeout client          20s
    timeout server          20s
    timeout http-keep-alive 10s
    timeout check           10s

#---------------------------------------------------------------------
# apiserver frontend which proxys to the control plane nodes
#---------------------------------------------------------------------
frontend apiserver
    bind *:6443
    mode tcp
    option tcplog
    default_backend apiserver

#---------------------------------------------------------------------
# round robin balancing for apiserver
#---------------------------------------------------------------------
backend apiserver
    option httpchk GET /healthz
    http-check expect status 200
    mode tcp
    option ssl-hello-chk
    balance     roundrobin
        #server ${HOST1_ID} ${HOST1_ADDRESS}:${APISERVER_SRC_PORT} check
        server master-1 172.16.133.56:6443 check
        server master-2 172.16.133.57:6443 check
        server master-3 172.16.133.58:6443 check
        # [...]

3.2 配置开机自启动与启动HAProxy

systemctl start haproxy
systemctl enable haproxy

3.3 查看启动日志

Jul 18 19:00:15 LoadBalancer-1 systemd: Started HAProxy Load Balancer.
Jul 18 19:00:15 LoadBalancer-1 haproxy[1712]: Proxy apiserver started.
Jul 18 19:00:15 LoadBalancer-1 haproxy-systemd-wrapper: [WARNING] 198/190015 (1712) : config : 'option forwardfor' ignored for frontend 'apiserver' as it requires HTTP mode.
Jul 18 19:00:15 LoadBalancer-1 haproxy-systemd-wrapper: [WARNING] 198/190015 (1712) : config : 'option forwardfor' ignored for backend 'apiserver' as it requires HTTP mode.
Jul 18 19:00:15 LoadBalancer-1 haproxy[1712]: Proxy apiserver started.
Jul 18 19:00:15 LoadBalancer-1 haproxy[1712]: Proxy apiserver started.
Jul 18 19:00:15 LoadBalancer-1 haproxy[1712]: Proxy apiserver started.
Jul 18 19:00:16 LoadBalancer-1 haproxy[1713]: Server apiserver/master-2 is DOWN, reason: Layer4 connection problem, info: "Connection refused", check duration: 0ms. 2 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue.
Jul 18 19:00:16 LoadBalancer-1 haproxy[1713]: Server apiserver/master-2 is DOWN, reason: Layer4 connection problem, info: "Connection refused", check duration: 0ms. 2 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue.
Jul 18 19:00:16 LoadBalancer-1 haproxy[1713]: Server apiserver/master-3 is DOWN, reason: Layer4 connection problem, info: "Connection refused", check duration: 0ms. 1 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue.
Jul 18 19:00:16 LoadBalancer-1 haproxy[1713]: Server apiserver/master-3 is DOWN, reason: Layer4 connection problem, info: "Connection refused", check duration: 0ms. 1 active and 0 backup servers left. 0 sessions active, 0 requeued, 0 remaining in queue.

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