Keepalived + Nginx 高可用

Posted 2021-09-07 菜鸟厚非

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部署

服务器	角色
192.168.91.135	master
192.168.91.136	backup
192.168.91.166	VIP

一、nginx 部署

分别在 master、backup 部署 Nginx，请参照 Nginx 部署

二、Keepalived 部署

分别在 master、backup 部署 Nginx，请参照 Keepalived 部署

三、配置

3.1 master

1 . 配置 keepalived.conf

vrrp_script：指定检查nginx工作状态脚本（根据nginx状态判断是否故障转移）
virtual_ipaddress：虚拟IP（VIP）

cat > /etc/keepalived/keepalived.conf << EOF
global_defs { 
   notification_email { 
     acassen@firewall.loc 
     failover@firewall.loc 
     sysadmin@firewall.loc 
   } 
   notification_email_from Alexandre.Cassen@firewall.loc  
   smtp_server 127.0.0.1 
   smtp_connect_timeout 30 
   router_id NGINX_MASTER
} 

vrrp_script check_nginx {
    script "/etc/keepalived/check_nginx.sh"
}

vrrp_instance VI_1 { 
    state MASTER 
    interface ens33  # 修改为实际网卡名
    virtual_router_id 51 # VRRP 路由 ID实例，每个实例是唯一的 
    priority 100    # 优先级，备服务器设置 90 
    advert_int 1    # 指定VRRP 心跳包通告间隔时间，默认1秒 
    authentication { 
        auth_type PASS      
        auth_pass 1111 
    }  
    # 虚拟IP
    virtual_ipaddress { 
        192.168.91.166/24
    } 
    track_script {
        check_nginx
    } 
}
EOF

2 . 配置检测 nginx 脚本，提供给 keepalived

cat > /etc/keepalived/check_nginx.sh  << "EOF"
#!/bin/bash
count=$(ss -antp |grep 6443 |egrep -cv "grep|$$")

if [ "$count" -eq 0 ];then
    exit 1
else
    exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh

注：keepalived根据脚本返回状态码（0为工作正常，非0不正常）判断是否故障转移。

3 . 重启 keepalived

systemctl restart keepalived

3.2 Backup

1 . 配置 keepalived.conf

cat > /etc/keepalived/keepalived.conf << EOF
global_defs { 
   notification_email { 
     acassen@firewall.loc 
     failover@firewall.loc 
     sysadmin@firewall.loc 
   } 
   notification_email_from Alexandre.Cassen@firewall.loc  
   smtp_server 127.0.0.1 
   smtp_connect_timeout 30 
   router_id NGINX_BACKUP
} 

vrrp_script check_nginx {
    script "/etc/keepalived/check_nginx.sh"
}

vrrp_instance VI_1 { 
    state BACKUP 
    interface ens33
    virtual_router_id 51 # VRRP 路由 ID实例，每个实例是唯一的 
    priority 90
    advert_int 1
    authentication { 
        auth_type PASS      
        auth_pass 1111 
    }  
    virtual_ipaddress { 
        192.168.91.166/24
    } 
    track_script {
        check_nginx
    } 
}
EOF

2 . 配置检测 nginx 脚本，提供给 keepalived

cat > /etc/keepalived/check_nginx.sh  << "EOF"
#!/bin/bash
count=$(ss -antp |grep 6443 |egrep -cv "grep|$$")

if [ "$count" -eq 0 ];then
    exit 1
else
    exit 0
fi
EOF
chmod +x /etc/keepalived/check_nginx.sh