Keepalived+HAproxy

拓撲

                               	                       ++++++++++++   
           					       +	 Client           +   192.168.122.200/24 (真實機作客戶端)
                                                       ++++++++++++   
                                             ________________|_______________  浮動IP eth0:1 192.168.122.199/24
                                            |                                              	     |
                                +++++++++++++          +++++++++++++                       
                                + HAproxy master  +           + HAproxy backup  +
                                +++++++++++++          +++++++++++++  
                       DIP eth0 192.168.122.201/24           DIP eth0 192.168.122.202/24
                                              |______________________________|
            			              ______________|_______________
                                              |                                           	| 
                                              |                                            	|
                                ++++++++++++              ++++++++++++
                                +        HTML A       +              +       HTML B        +
                                ++++++++++++              ++++++++++++
                             eth0 192.168.122.203/24        eth0 192.168.122.204/24

*分別在HAproxy master、HAproxy backup 上部署浮動IP，測試2個HAproxy單獨工做都正常。測試完成後都撤掉浮動IP。
##############################################################
解析
192.168.122.200 client.com
192.168.122.201 HAm.com
192.168.122.202 HAb.com
192.168.122.203 web1.com
192.168.122.204 web2.com
##############################################################

web端

 HTML  A  B
  [root@web1 ~]# yum install -y httpd           192.168.122.203/24
  [root@web2 ~]# yum install -y httpd          192.168.122.204/24
  [root@web1 ~]#  systemctl start httpd
  [root@web1 ~]#  echo web1111111111  > /var/www/html/index.html 
  [root@web2 ~]#  echo web2222222222  > /var/www/html/index.html 
############################################################## 
 
 HAproxy master & HAproxy backup
 # yum install  -y  haproxy  keepalived 
[root@HAm ~]## cat /etc/haproxy/haproxy.cfg   注意：haproxy2配置文件同樣
global
    log         127.0.0.1 local2

    chroot      /var/lib/haproxy
    pidfile     /var/run/haproxy.pid
    maxconn     4000
    user        haproxy
    group       haproxy
    daemon

    # turn on stats unix socket
    stats socket /var/lib/haproxy/stats
defaults
    mode                    http
    log                     global
    option                  httplog
    option                  dontlognull
    option http-server-close
    option forwardfor       except 127.0.0.0/8
    option                  redispatch
    retries                 3
    timeout http-request    10s
    timeout queue           1m
    timeout connect         10s
    timeout client          1m
    timeout server          1m
    timeout http-keep-alive 10s
    timeout check           10s
    maxconn                 3000

 frontend  main *:80
     acl html url_reg -i  \.html$
     use_backend  webserver if html

 backend webserver
    balance roundrobin
    option httpchk GET /index.html
#   cookie SERVERID insert indirect nocache
    server html-A 192.168.122.203:80 weight 1  check inter 2000 rise 2 fall 5
    server html-B 192.168.122.204:80 weight 1  check inter 2000 rise 2 fall 5
backend app
    balance     roundrobin
    server  app1 127.0.0.1:5001 check
    server  app2 127.0.0.1:5002 check
    server  app3 127.0.0.1:5003 check
    server  app4 127.0.0.1:5004 check
[root@HAm ~]# scp /etc/haproxy/haproxy.cfg  192.168.122.202:/etc/haproxy/haproxy.cfg

[root@HAm ~]# cat /etc/keepalived/keepalived.conf     注意：在haproxy2中 主要修改BACKUP和100
! Configuration File for keepalived
global_defs {
   notification_email {
        root@localhost
 }
   notification_email_from Alexandre.keepalived@localhost
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id HAproxy
}

vrrp_instance VI_1 {
    state MASTER  切換  （BACKUP）
    interface eth0
    virtual_router_id 51
    priority 150 切換 （100）
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.122.199/24
    }
}

 注意：當haproxy1宕機時候是192.168.122.199/24切換到haproxy2下
[root@HAm ~]# ip a 
 eth0:
    inet 192.168.122.201/24 brd 192.168.122.255 scope global noprefixroute eth0
       valid_lft forever preferred_lft forever
    inet 192.168.122.199/24 scope global secondary eth0
       valid_lft forever preferred_lft forever
  [root@HAb ~]# ip a 
eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 52:90:68:be:9e:65 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.202/24 brd 192.168.122.255 scope global noprefixroute eth0
       valid_lft forever preferred_lft forever


自動切換腳本：（腳本主要是爲了當haproxy1宕機時候切換到haproxy2上繼續操做）
[root@HAm ~]# vi /etc/keepalived/chk_haproxy.sh
#!/bin/bash
# 去掉表頭定義haproxy 出現的次數爲A
A=`ps -C haproxy --no-header | wc -l`
# 若是出現次數爲0 ，則沒有啓動haproxy服務
if [ $A -eq 0 ]
        then  systemctl start haproxy
                sleep 3
# 若是出現次數等於0，則中止haproxy服務
                if [ `ps -C haproxy --no-header | wc -l `  -eq 0 ]
                then  stop keepalived
                fi
fi
[root@HAm ~]# chmod +x /etc/keepalived/chk_haproxy.sh
[root@HAm ~]#  scp /etc/keepalived/chk_haproxy.sh 192.168.122.202:/etc/keepalived/

#  systemctl start haproxy
#  systemctl start keepalived

腳本
[root@HAm ~]# vi /etc/keepalived/chk_ipvsadm.sh

#!/bin/bash
# 去掉表頭定義ipvsadm 出現的次數爲A
A=`ipvsadm -L | wc -l`
# 若是出現次數爲0 ，則沒有啓動ipvsadm服務
if [ $A -lt 6 ]
        then  systemctl start keepalived
                sleep 3
# 若是出現次數等於0，則中止ipvsadm服務
                if [ `ipvsadm -L | wc -l `  -lt 6 ]
                then  stop keepalived
                fi
fi
[root@HAm ~]# chmod +x  /etc/keepalived/chk_ipvsadm.sh
[root@HAm ~]#  scp /etc/keepalived/chk_ipvsadm.sh   192.168.122.202:/etc/keepalived/chk_ipvsadm.sh

##############################################################
效果：
[root@client ~]# curl 192.168.122.199/index.html
web1111111111
[root@client ~]# curl 192.168.122.199/index.html
web2222222222
[root@client ~]# curl 192.168.122.199/index.html
web1111111111
[root@client ~]# curl 192.168.122.199/index.html
web2222222222

注意：當haproxy1 宕機時候依然能夠繼續運行