Keepalived+Nginx 高可用集群（主从模式）
集群架构图：
说明：Keepalived机器同样是nginx负载均衡器。
1）实验环境准备（此处都是使用的centos7系统）
# cat /etc/redhat-release CentOS Linux release 7.4.1708 (Core)
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 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 keepalived global_defs { notification_email { 381347268@qq.com } smtp_server 192.168.200.1 smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_instance VI_1 { state MASTER interface ens33 virtual_router_id 51 priority 150 advert_int 1 authentication { auth_type PASS auth_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 1000 link/ether 00:0c:29:94:17:44 brd ff:ff:ff:ff:ff:ff inet 192.168.1.31/24 brd 192.168.1.255 scope global ens33 valid_lft forever preferred_lft forever inet 192.168.1.110/24 scope global secondary ens33:1 valid_lft forever preferred_lft forever inet6 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 keepalived global_defs { notification_email { 381347268@qq.com } smtp_server 192.168.200.1 smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_instance VI_1 { state BACKUP interface ens33 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_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 1500 inet 192.168.1.32 netmask 255.255.255.0 broadcast 192.168.1.255 inet6 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 0 TX 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 1500 inet 192.168.1.31 netmask 255.255.255.0 broadcast 192.168.1.255 inet6 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 0 TX 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 1500 inet 192.168.1.32 netmask 255.255.255.0 broadcast 192.168.1.255 inet6 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 0 TX 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 1500 inet 192.168.1.110 netmask 255.255.255.0 broadcast 0.0.0.0 ether 00:0c:29:ab:65:32 txqueuelen 1000 (Ethernet) ...
到此，Keepalived+Nginx高可用集群（主从）就搭建完成了。
Keepalived+Nginx 高可用集群（双主模式）
将keepalived做成双主模式，其实很简单，就是再配置一段新的vrrp_instance（实例）规则，主上面加配置一个从的实例规则，从上面加配置一个主的实例规则。
集群架构图：
说明：还是按照上面的环境继续做实验，只是修改LB节点上面的keepalived服务的配置文件即可。此时LB-01节点即为Keepalived的主节点也为备节点，LB-02节点同样即为Keepalived的主节点也为备节点。LB-01节点默认的主节点VIP（192.168.1.110），LB-02节点默认的主节点VIP（192.168.1.210）
1）配置 LB-01 节点
[root@LB-01 ~]# vim /etc/keepalived/keepalived.conf //编辑配置文件，增加一段新的vrrp_instance规则 ! Configuration File for keepalived global_defs { notification_email { 381347268@qq.com } smtp_server 192.168.200.1 smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_instance VI_1 { state MASTER interface ens33 virtual_router_id 51 priority 150 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.1.110/24 dev ens33 label ens33:1 } } vrrp_instance VI_2 { state BACKUP interface ens33 virtual_router_id 52 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 2222 } virtual_ipaddress { 192.168.1.210/24 dev ens33 label ens33:2 } }
[root@LB-01 ~]# systemctl restart keepalived //重新启动keepalived
// 查看LB-01 节点的IP地址，发现VIP（192.168.1.110）同样还是默认在该节点 [root@LB-01 ~]# ip a 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:94:17:44 brd ff:ff:ff:ff:ff:ff inet 192.168.1.31/24 brd 192.168.1.255 scope global ens33 valid_lft forever preferred_lft forever inet 192.168.1.110/24 scope global secondary ens33:1 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:fe94:1744/64 scope link valid_lft forever preferred_lft forever
2）配置 LB-02 节点
[root@LB-02 ~]# vim /etc/keepalived/keepalived.conf //编辑配置文件，增加一段新的vrrp_instance规则 ! Configuration File for keepalived global_defs { notification_email { 381347268@qq.com } smtp_server 192.168.200.1 smtp_connect_timeout 30 router_id LVS_DEVEL } vrrp_instance VI_1 { state BACKUP interface ens33 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.1.110/24 dev ens33 label ens33:1 } } vrrp_instance VI_2 { state MASTER interface ens33 virtual_router_id 52 priority 150 advert_int 1 authentication { auth_type PASS auth_pass 2222 } virtual_ipaddress { 192.168.1.210/24 dev ens33 label ens33:2 } }
[root@LB-02 ~]# systemctl restart keepalived //重新启动keepalived
// 查看LB-02节点IP，会发现也多了一个VIP（192.168.1.210），此时该节点也就是一个主了。 [root@LB-02 ~]# ip a 2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000 link/ether 00:0c:29:ab:65:32 brd ff:ff:ff:ff:ff:ff inet 192.168.1.32/24 brd 192.168.1.255 scope global ens33 valid_lft forever preferred_lft forever inet 192.168.1.210/24 scope global secondary ens33:2 valid_lft forever preferred_lft forever inet6 fe80::20c:29ff:feab:6532/64 scope link valid_lft forever preferred_lft forever
3）测试
[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 192.168.1.210 web01 192.168.1.33 [root@node01 ~]# curl 192.168.1.210 web02 192.168.1.34
// 停止LB-01节点的keepalived再次测试 [root@LB-01 ~]# systemctl stop keepalived [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 192.168.1.210 web01 192.168.1.33 [root@node01 ~]# curl 192.168.1.210 web02 192.168.1.34
测试可以发现我们访问keepalived中配置的两个VIP都可以正常调度等，当我们停止任意一台keepalived节点，同样还是正常访问；到此，keepalived+nginx高可用集群（双主模式）就搭建完成了。