如何创建浮动IP并使用它来配置HAProxy

Question

我最近尝试使用HAProxy对我的应用程序进行负载均衡,并且能够成功完成.后来,我遇到了一个名为Floating IP的概念,它可以与keepalived一起使用,以使负载均衡器具有高可用性.虽然我无法理解如何创建浮动Ip.如何创建浮动IP并使用它来配置HAProxy？谢谢.

Answer 1

假设:

• 这适用于Ubuntu 14.04
• haproxy-primary IP:198.51.100.10
• haproxy-secondary IP:198.51.100.20
• 共享IP:198.51.100.50
• 任何DNS规则都应指向共享IP(198.51.100.50)

脚步:

1. 为keepalived添加防火墙规则#224.0.0.18是keepalived组播地址
   1. sudo ufw allow in from 198.51.100.20 to 224.0.0.18 #198.51.100.10
   2. sudo ufw allow in from 198.51.100.10 to 224.0.0.18 #198.51.100.20
2. 允许访问共享的IP地址
   1. 编辑 /etc/sysctl.conf
   2. 组 net.ipv4.ip_nonlocal_bind=1
   3. sudo sysctl -p #reload config change
3. 安装keepalived
   1. sudo apt-get install keepalived
4. 在两台服务器上配置keepalived
   1. 编辑/创建 /etc/keepalived/keepalived.conf
   2. 请参阅下面的示例文件#主服务器和辅助服务器上的优先级必须不同!
5. 重新启动keepalived
   1. sudo service keepalived restart
6. 收听共享的IP地址
   1. 编辑 /etc/haproxy/haproxy.cfg
   2. bind 198.51.100.50:80
7. 重启haproxy(在两个haproxy服务器上)
   1. sudo service haproxy restart
8. 验证正确的故障转移
   1. primary:sudo ip addr show | grep eth0#应列出共享IP
   2. secondary:sudo ip addr show | grep eth0#不应列出共享IP
   3. 主: sudo service haproxy stop
   4. primary:sudo ip addr show | grep eth0#不应列出共享IP
   5. secondary:sudo ip addr show | grep eth0#应列出共享IP
   6. 主: sudo service haproxy start
   7. primary:sudo ip addr show | grep eth0#应列出共享IP
   8. secondary:sudo ip addr show | grep eth0#不应列出共享IP

/etc/keepalived/keepalived.conf

     vrrp_script chk_haproxy {      # Requires keepalived-1.1.13
       script "killall -0 haproxy"  # cheaper than pidof
       interval 2 # check every 2 seconds
       weight 2 # add 2 points of priority if OK
     }
     vrrp_instance VI_1 {
       interface eth0
       state MASTER
       virtual_router_id 51
       priority 101 # 101 on primary, 100 on secondary
       virtual_ipaddress {
         198.51.100.50
       }
       track_script {
         chk_haproxy
       }
     }