公網服務器使用docker、keepalived和Nginx模擬高可用

前言

最近學習高可用，但手上只有一臺服務器，所以使用docker容器、keepalived和Nginx模擬場景。目標：從最開始的安裝docker到最後實現高可用。

開始

安裝docker

可參考我以前的博客：centos7中安裝docker

下載鏡像

docker pull centos:7

容器準備

生成容器並進入

docker run -itd --privileged=true --name=centos_kn centos:7 init
docker exec -it centos_kn bash

安裝工具

yum install vim net-tools rsyslog ipvsadm initscripts libnl3-devel ipset-devel -y

安裝keepalived

yum install -y gcc openssl-devel popt-devel 
yum install keepalived -y

安裝nginx

rpm -Uvh http://nginx.org/packages/centos/7/noarch/RPMS/nginx-release-centos-7-0.el7.ngx.noarch.rpm
yum install nginx -y
#啓動nginx
nginx
#設置開機啓動
systemctl enable nginx

打包容器

docker commit -a lwh -m 'centos with keepalived nginx' centos_kn centos_kn

進入容器

宿主機也需要安裝keepalived並運行

yum install -y gcc openssl-devel popt-devel 
yum install keepalived -y
systemctl start keepalived
#運行完成後可以停止
systemctl stop keepalived

master容器

#進入master容器
docker run -itd --privileged=true --name=centos_master centos_kn init
docker exec -it centos_master bash
#設置keepalived配置
cd /etc/keepalived
#備份keepalived.conf
cp keepalived.conf keepalived.conf.bak
#更改配置，配置見下邊master配置
#啓動keepalived
systemctl start keepalived
#設置開啓啓動
systemctl enable keepalived
#設置nginx頁面顯示
echo master > /usr/share/nginx/html/index.html 

master配置

! Configuration File for keepalived

global_defs {
   notification_email {
     [email protected]
   }
   notification_email_from [email protected]
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_MASTER
   #vrrp_skip_check_adv_addr
   #vrrp_strict
   #vrrp_garp_interval 0
   #vrrp_gna_interval 0
}

vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }

    virtual_ipaddress {
        172.17.100.100
    }
}


virtual_server 172.17.100.100 80 {
    delay_loop 6
    lb_algo rr
    lb_kind DR
    #persistence_timeout 0
    protocol TCP

    real_server 172.17.0.2 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            retry 3
            delay_before_retry 3
        }
    }
    real_server 172.17.0.3 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            retry 3
            delay_before_retry 3
        }
    }

}

slave容器

#進入backup容器
docker run -itd --privileged=true --name=centos_slave centos_kn init
docker exec -it centos_slave bash
#設置keepalived配置
cd /etc/keepalived
#備份keepalived.conf
cp keepalived.conf keepalived.conf.bak
#更改配置，配置見下邊master配置
#啓動keepalived
systemctl start keepalived
#設置開啓啓動
systemctl enable keepalived
#設置nginx頁面顯示
echo slave> /usr/share/nginx/html/index.html 

slave配置

! Configuration File for keepalived

global_defs {
   notification_email {
     [email protected]
   }
   notification_email_from [email protected]
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id LVS_SLAVE
   #vrrp_skip_check_adv_addr
   #vrrp_strict
   #vrrp_garp_interval 0
   #vrrp_gna_interval 0
}

vrrp_instance VI_2 {
    state BACKUP
    interface eth0
    virtual_router_id 51
    priority 80
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }

    virtual_ipaddress {
        172.17.100.100
    }
}

virtual_server 172.17.100.100 80 {
    delay_loop 6
    lb_algo rr
    lb_kind DR
    #persistence_timeout 0
    protocol TCP
    
    real_server 172.17.0.3 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            retry 3
            delay_before_retry 3
        }
    }
    real_server 172.17.0.2 80 {
        weight 1
        TCP_CHECK {
            connect_timeout 3
            retry 3
            delay_before_retry 3
        }
    }
}                                       

容器配置

兩個容器都需要執行，否則無法輪詢

#!/bin/bash
echo 1 > /proc/sys/net/ipv4/conf/lo/arp_ignore
echo 2 > /proc/sys/net/ipv4/conf/lo/arp_announce
echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore
echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce
ifconfig lo:0 172.17.100.100 broadcast 172.17.100.100 netmask 255.255.255.255 up
route add -host 172.17.100.100 dev lo:0

測試是否配置成功

進入宿主機
首先使用curl訪問虛擬ip:
curl 172.17.100.100
能看到返回的值說明配置成功了

使用公網訪問

#開啓防火牆
systemctl start firewalld.service
#查看防火牆狀態，顯示爲running
firewall-cmd --state
#開通80端口
firewall-cmd --zone=public --add-port=80/tcp --permanent 
#設置端口轉發
firewall-cmd --permanent --zone=public --add-forward-port=port=80:proto=tcp:toaddr=172.17.100.100:toport=80
#刷新防火牆
firewall-cmd --reload

測試

使用瀏覽器訪問會發現達不到輪詢的效果，使用jmeter壓測可以看到輪詢的效果