Keepalived 简单实现 Nginx 的高可用

文章

林里克斯

171字数

Linux

实验平台：CentOS Linux release 7.9.2009

keepalived Version：Keepalived v2.1.5

Nginx Version：nginx/1.16.1

VIP：10.10.12.100 / Keepalived1(Nginx1)：10.10.12.5 / Keepalived12(Nginx2)：10.10.12.6

一、环境搭建

1.安装 keepalived

$ yum -y install keepalived
#这里测试就使用了 yum 来安装了,2 个节点都要安装

其他安装方式可以参考 -> Linux 下搭建 Keepalived

2.安装 Nginx

$ yum -y install nginx
#这里测试就使用了 yum 来安装了,2 个节点都要安装

其他安装方式可以参考 -> Linux 下编译安装 Nginx

3.修改下 Nginx 的页面方便测试

$ vim /usr/share/nginx/html/index.html
<h1>CentOS 1</h1>
#主节点的

$ vim /usr/share/nginx/html/index.html
<h1>CentOS 2</h1>
#备节点的

二、配置 Keepalived

1.编辑主节点配置文件 keepalived.conf

$ vim /data/keepalived/conf/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id nginx01
}

vrrp_instance VI_1 {
    state MASTER
    interface ens33
    virtual_router_id 51
    mcast_src_ip 10.10.12.5
    priority 100
    advert_int 1              
    authentication {
        auth_type PASS
        auth_pass 111111
    }
    virtual_ipaddress {
        10.10.12.100/24 brd 10.10.12.255 dev ens33 lable ens33:0
    }
}

virtual_server 10.10.12.100 80 {
    delay_loop 6
    lb_algo wrr
    lb_kind DR
    persistence_timeout 50
    protocol TCP

    sorry_server 127.0.0.1 80

    real_server 10.10.12.5 80 {
        weight 1
        HTTP_GET {
            url {
              path /
              status_code 200
            }
            connect_timeout 1
            retry 3
            delay_before_retry 1
        }
    }

    real_server 10.10.12.6 80 {
        weight 3
        HTTP_GET {
            url {
              path /
              status_code 200
            }
            connect_timeout 1
            retry 3
            delay_before_retry 1
        }
    }
}

2.编辑备节点 keepalived.conf

$ vim /data/keepalived/conf/keepalived/keepalived.conf

! Configuration File for keepalived

global_defs {
   router_id nginx02
}

vrrp_instance VI_1 {
    state BACKUP
    interface ens33
    virtual_router_id 51
    mcast_src_ip 10.10.12.6
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 111111
    }
    virtual_ipaddress {
        10.10.12.100/24 brd 10.10.12.255 dev ens33 lable ens33:0
    }
}

virtual_server 10.10.12.100 80 {
    delay_loop 6
    lb_algo wrr
    lb_kind DR
    persistence_timeout 50
    protocol TCP

    sorry_server 127.0.0.1 80

    real_server 10.10.12.5 80 {
        weight 1
        HTTP_GET {
            url {
              path /
              status_code 200
            }
            connect_timeout 1
            retry 3
            delay_before_retry 1
        }
    }

    real_server 10.10.12.6 80 {
        weight 3
        HTTP_GET {
            url {
              path /
              status_code 200
            }
            connect_timeout 1
            retry 3
            delay_before_retry 1
        }
    }
}

3.各节点启动服务

$ systemctl start keepalived

4.查看 2 节点 ip 地址，我这里方便对比，使用 ansible

$ ansible keepalived -m shell -a "ip a s ens33"
10.10.12.6 | CHANGED | rc=0 >>
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:5c:d9:2d brd ff:ff:ff:ff:ff:ff
    inet 10.10.12.6/24 brd 10.10.12.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::de8b:5b08:ee0f:8e47/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
10.10.12.5 | CHANGED | rc=0 >>
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:26:54:bf brd ff:ff:ff:ff:ff:ff
    inet 10.10.12.5/24 brd 10.10.12.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 10.10.12.100/24 brd 10.10.12.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::df07:293c:e304:f9c/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
#多了一个 10.10.12.100 的ip

三、验证效果

1.写个循环访问验证

$ while true;do curl 10.10.12.100; sleep 1;done

2.直观验证

$ sudo systemctl stop nginx

3.查看 VIP ,发现 VIP 漂移到了另外一台上

$ ansible keepalived -m shell -a "ip a s ens33"
10.10.12.6 | CHANGED | rc=0 >>
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:5c:d9:2d brd ff:ff:ff:ff:ff:ff
    inet 10.10.12.6/24 brd 10.10.12.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet 10.10.12.100/24 scope global secondary ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::de8b:5b08:ee0f:8e47/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever
10.10.12.5 | CHANGED | rc=0 >>
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 00:0c:29:26:54:bf brd ff:ff:ff:ff:ff:ff
    inet 10.10.12.5/24 brd 10.10.12.255 scope global noprefixroute ens33
       valid_lft forever preferred_lft forever
    inet6 fe80::df07:293c:e304:f9c/64 scope link tentative noprefixroute dadfailed 
       valid_lft forever preferred_lft forever