（1）在所有节点上面进行配置

# systemctl stop firewalld //关闭防火墙
# sed -i 's/^SELINUX=.*/SELINUX=disabled/' /etc/sysconfig/selinux //关闭 selinux，重启生效
# setenforce 0 //关闭 selinux，临时生效
# ntpdate 0.centos.pool.ntp.org //时间同步
# yum install nginx -y //安装 nginx

（2）配置后端 web 服务器（两台一样）

# echo "`hostname` `ifconfig ens33 |sed -n 's#.*inet \(.*\)netmask.*#\1#p'`" > 
/usr/share/nginx/html/index.html //准备测试文件，此处是将主机名和 ip 写到 index.html 页面中
# vim /etc/nginx/nginx.conf //编辑配置文件
state BACKUP # 备份服务器上将 MASTER 改为 BACKUP user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
include /usr/share/nginx/modules/ *.conf;
events {worker_connections 1024;
}
http {log_format main '$remote_addr - $remote_user [$time_local] "$request" ''$status $body_bytes_sent "$http_referer" ''"$http_user_agent" "$http_x_forwarded_for"';access_log /var/log/nginx/access.log main;sendfile on;tcp_nopush on;tcp_nodelay on;keepalive_timeout 65;types_hash_max_size 2048;include /etc/nginx/mime.types;default_type application/octet-stream;include /etc/nginx/conf.d/ *.conf;server {listen 80;server_name www.mtian.org;location / {root /usr/share/nginx/html;}access_log /var/log/nginx/access.log main;} 
}
# systemctl start nginx //启动 nginx
# systemctl enable nginx //加入开机启动

（3）配置 LB 服务器（两台都一样）

# vim /etc/nginx/nginx.conf
user nginx;
worker_processes auto;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;
include /usr/share/nginx/modules/　*.conf;
events {worker_connections 1024;
}
http {log_format main '$remote_addr - $remote_user [$time_local] "$request" ''$status $body_bytes_sent "$http_referer" ''"$http_user_agent" "$http_x_forwarded_for"';access_log /var/log/nginx/access.log main;sendfile on;tcp_nopush on;tcp_nodelay on;keepalive_timeout 65;types_hash_max_size 2048;include /etc/nginx/mime.types;default_type application/octet-stream;include /etc/nginx/conf.d/ *.conf;upstream backend {server 192.168.1.33:80 weight=1 max_fails=3 fail_timeout=20s;server 192.168.1.34:80 weight=1 max_fails=3 fail_timeout=20s;}server {listen 80;server_name www.mtian.org;location / {proxy_pass http://backend;proxy_set_header Host $host:$proxy_port;proxy_set_header X-Forwarded-For $remote_addr;}} 
}
# systemctl start nginx //启动 nginx 
# systemctl enable nginx //加入开机自启动

（4）在测试机（192.168.1.35）上面添加 host 解析，并测试 lb 集群是否正常。（测试机任意都可以，只要能访问 lb 节点。）

[root@node01 ~]# cat /etc/hosts
127.0.0.1 localhost localhost.localdomain localhost4 localhost4.localdomain4
::1 　　　localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.1.32　 www.mtian.org
192.168.1.31　 www.mtian.org
// 测试时候轮流关闭 lb1 和 lb2 节点，关闭后还是能够访问并看到轮循效果即表示 nginx lb 集群搭建成功。
[root@node01 ~]# curl www.mtian.org
web01 192.168.1.33 
[root@node01 ~]# curl www.mtian.org
web02 192.168.1.34 
[root@node01 ~]# curl www.mtian.org
web01 192.168.1.33 
[root@node01 ~]# curl www.mtian.org
web02 192.168.1.34 
[root@node01 ~]# curl www.mtian.org
web01 192.168.1.33 
[root@node01 ~]# curl www.mtian.org
web02 192.168.1.34

（5）上面步骤成功后，开始搭建 keepalived，在两台 lb 节点上面安装 keepalived（也可以源码编译安装、此处直接使用 yum 安装）

# yum install keepalived -y 

（6）配置 LB-01 节点

[root@LB-01 ~]# vim /etc/keepalived/keepalived.conf
! Configuration File for keepalivedglobal_defs {notification_email {381347268@qq.com}smtp_server 192.168.200.1smtp_connect_timeout 30router_id LVS_DEVEL
}
vrrp_instance VI_1 {state MASTERinterface ens33virtual_router_id 51priority 150advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.1.110/24 dev ens33 label ens33:1}
}
[root@LB-01 ~]# systemctl start keepalived //启动 keepalived
[root@LB-01 ~]# systemctl enable keepalived //加入开机自启动
[root@LB-01 ~]# ip a //查看 IP，会发现多出了 VIP 192.168.1.110
......
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000link/ether 00:0c:29:94:17:44 brd ff:ff:ff:ff:ff:ffinet 192.168.1.31/24 brd 192.168.1.255 scope global ens33valid_lft forever preferred_lft foreverinet 192.168.1.110/24 scope global secondary ens33:1valid_lft forever preferred_lft foreverinet6 fe80::20c:29ff:fe94:1744/64 scope link valid_lft forever preferred_lft forever
......

（7）配置 LB-02 节点

[root@LB-02 ~]# vim /etc/keepalived/keepalived.conf 
! Configuration File for keepalivedglobal_defs {notification_email {381347268@qq.com}smtp_server 192.168.200.1smtp_connect_timeout 30router_id LVS_DEVEL
}
vrrp_instance VI_1 {state BACKUPinterface ens33virtual_router_id 51priority 100advert_int 1authentication {auth_type PASSauth_pass 1111}virtual_ipaddress {192.168.1.110/24 dev ens33 label ens33:1}
}
[root@LB-02 ~]# systemctl start keepalived //启动 keepalived
[root@LB-02 ~]# systemctl enable keepalived //加入开机自启动
[root@LB-02 ~]# ifconfig //查看 IP，此时备节点不会有 VIP（只有当主挂了的时候，VIP 才会飘到备节点）
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500inet 192.168.1.32 netmask 255.255.255.0 broadcast 192.168.1.255inet6 fe80::20c:29ff:feab:6532 prefixlen 64 scopeid 0x20<link>ether 00:0c:29:ab:65:32 txqueuelen 1000 (Ethernet)RX packets 43752 bytes 17739987 (16.9 MiB)RX errors 0 dropped 0 overruns 0 frame 0TX packets 4177 bytes 415805 (406.0 KiB)TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
......

（8）在测试机器上面访问 Keepalived 上面配置的 VIP 192.168.1.110

[root@node01 ~]# curl 192.168.1.110
web01 192.168.1.33 
[root@node01 ~]# curl 192.168.1.110
web02 192.168.1.34 
[root@node01 ~]# curl 192.168.1.110
web01 192.168.1.33 
[root@node01 ~]# curl 192.168.1.110
web02 192.168.1.34//关闭 LB-01 节点上面 keepalived 主节点。再次访问
[root@LB-01 ~]# systemctl stop keepalived
[root@node01 ~]# 
[root@node01 ~]# curl 192.168.1.110
web01 192.168.1.33 
[root@node01 ~]# curl 192.168.1.110
web02 192.168.1.34 
[root@node01 ~]# curl 192.168.1.110
web01 192.168.1.33 
[root@node01 ~]# curl 192.168.1.110
web02 192.168.1.34
//此时查看 LB-01 主节点上面的 IP ，发现已经没有了 VIP
[root@LB-01 ~]# ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500inet 192.168.1.31 netmask 255.255.255.0 broadcast 192.168.1.255inet6 fe80::20c:29ff:fe94:1744 prefixlen 64 scopeid 0x20<link>ether 00:0c:29:94:17:44 txqueuelen 1000 (Ethernet)RX packets 46813 bytes 18033403 (17.1 MiB)RX errors 0 dropped 0 overruns 0 frame 0TX packets 9350 bytes 1040882 (1016.4 KiB)TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
...
//查看 LB-02 备节点上面的 IP，发现 VIP 已经成功飘过来了
[root@LB-02 ~]# ifconfig
ens33: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500inet 192.168.1.32 netmask 255.255.255.0 broadcast 192.168.1.255inet6 fe80::20c:29ff:feab:6532 prefixlen 64 scopeid 0x20<link>ether 00:0c:29:ab:65:32 txqueuelen 1000 (Ethernet)RX packets 44023 bytes 17760070 (16.9 MiB)RX errors 0 dropped 0 overruns 0 frame 0TX packets 4333 bytes 430037 (419.9 KiB)TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
ens33:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500inet 192.168.1.110 netmask 255.255.255.0 broadcast 0.0.0.0ether 00:0c:29:ab:65:32 txqueuelen 1000 (Ethernet)...

到此，Keepalived+Nginx 高可用集群就搭建完成了。