keepalived 实现高可用，负载均衡

浅浅的花香味﹌ 2023-07-11 06:28 66阅读 0赞

### 文章目录 ###

*  1, 单个nginx反向代理tomcat
 *   *  a, web环境主备：两个tomcat服务
     *  b, 单个nginx反向代理
 *  2, 两个(keepalived+ nginx) 代理tomcat
 *   *  a, 配置nginx监听vip：在keepalived所有节点
     *  b, master节点配置keepalived+nginx
     *  c, backup节点配置keepalived+nginx
     *   *  keepalived的notify状态通知脚本
     *  d, 测试keepalived
 *  3, 手动添加/删除：虚拟IP
 *   *  a, Windows cmd管理虚拟ip
     *  b, CentOS 管理虚拟IP
     *   *  a, 一块网卡，多个ip
         *   *  临时修改：ip addr
             *  永久修改：网卡配置文件
         *  b, 一块网卡，多个别名
         *   *  CentOS7: ip addr
             *  CentOS6: ifconfig 网卡

# 1, 单个nginx反向代理tomcat #

<table> 
 <thead> 
  <tr> 
   <th>角色</th> 
   <th>主机名</th> 
   <th align="left">端口说明</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>web主机</td> 
   <td>web-tomcat-docker</td> 
   <td align="left">tomcat1/8081, tomcat2/8082</td> 
  </tr> 
  <tr> 
   <td>代理主机1</td> 
   <td>proxy-c7</td> 
   <td align="left">nginx: listen: *:88</td> 
  </tr> 
 </tbody> 
</table>

## a, web环境主备：两个tomcat服务 ##

[root1@web-tomcat-docker ~]#
    docker run -d --name tomcat1 -p 8081:8080 daocloud.io/library/tomcat:8.0.44
    docker run -d --name tomcat2 -p 8082:8080 daocloud.io/library/tomcat:8.0.44
    docker exec -it tomcat1 bash -c " echo 'this is tomcat1:8081' > /usr/local/tomcat/webapps/ROOT/index.jsp"
    docker exec -it tomcat2 bash -c " echo 'this is tomcat2:8082' > /usr/local/tomcat/webapps/ROOT/index.jsp"
    
    [root1@web-tomcat-docker ~]# curl localhost:8081
    this is tomcat1:8081
    [root1@web-tomcat-docker ~]# curl localhost:8082
    this is tomcat2:8082

## b, 单个nginx反向代理 ##

[root@proxy-c7 ~]# cat /etc/nginx/conf.d/proxy.conf
    upstream web{ 
      server web-tomcat-docker:8081;
      server web-tomcat-docker:8082;
    }
    server { 
      #listen 192.168.56.251:88;
      listen *:88;
    
      location / { 
            proxy_pass http://web;
             proxy_set_header  X-Real-IP $remote_addr;
              proxy_set_header  REMOTE-HOST $remote_addr;
              proxy_set_header  Host $host;
              proxy_set_header  X-Forwarded-For $proxy_add_x_forwarded_for;
      }
    }
    
    
    [root@proxy-c7 ~]# curl localhost:88
    this is tomcat1:8081
    [root@proxy-c7 ~]# curl localhost:88
    this is tomcat2:8082

# 2, 两个(keepalived+ nginx) 代理tomcat #

使用keepalived维护虚拟ip: 在主备节点漂移

<table> 
 <thead> 
  <tr> 
   <th>角色</th> 
   <th>主机名</th> 
   <th align="left">端口说明</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>web主机</td> 
   <td>web-tomcat-docker</td> 
   <td align="left">tomcat1/8081, tomcat2/8082</td> 
  </tr> 
  <tr> 
   <td>keepalived+nginx代理主机1</td> 
   <td>proxy-c7</td> 
   <td align="left">nginx: listen: vip:88</td> 
  </tr> 
  <tr> 
   <td>keepalived+nginx代理主机2</td> 
   <td>proxy-c6</td> 
   <td align="left">nginx: listen: vip:88</td> 
  </tr> 
 </tbody> 
</table>

## a, 配置nginx监听vip：在keepalived所有节点 ##

#运行系统监听不存在的端口
    sysctl -w net.ipv4.ip_nonlocal_bind=1
    echo net.ipv4.ip_nonlocal_bind=1 >> /etc/sysctl.conf
    
    #修改nginx 监听vip
    cat > /etc/nginx/conf.d/proxy.conf <<EOF upstream web{ server web-tomcat-docker:81; server web-tomcat-docker:82; } server { #listen *:88; #监听虚拟IP listen 192.168.56.251:88; location / { proxy_pass http://web; proxy_set_header X-Real-IP \$remote_addr; proxy_set_header REMOTE-HOST \$remote_addr; proxy_set_header Host \$host; proxy_set_header X-Forwarded-For \$proxy_add_x_forwarded_for; } } EOF
    
    #重启Nginx, reload会不管用
    systemctl restart nginx

## b, master节点配置keepalived+nginx ##

#vrrp_sript: weight权重使用说明：
    #master : 100--> 初始优先级=100,nginx发生故障,keepalived vrrp优先级-30,变为70 (比backup小，角色对调)
    #backup1: 90 
    #backup2: 90 
    [root@proxy-c7 ~]# cat /etc/keepalived/keepalived.conf
    global_defs { 
       router_id LVS_DEVEL_162
    }
    
    vrrp_script chk_keep {   
      #script [ 0 -eq 0 ] && exit 0 || exit 1
      #script /tmp/chk_nginx.sh: service nginx status
      script "service nginx status"
      interval 1
      weight -30
    }
    
    vrrp_instance VI_1_test1 { 
        state MASTER  #主备不同
        interface eth1
        virtual_router_id 51
        priority 100 #主备不同
        advert_int 1
        authentication { 
            auth_type PASS
            auth_pass 1111
        }
        virtual_ipaddress { 
            192.168.56.251
        }
        vrrp_macst_group4 224.0.10.67
        track_script { 
          chk_keep
        }
    # #发送通知: master状态时,backup状态时.. 
         notify_master "service nginx start"
    # notify_master "/etc/keepalived/notify.sh master"
    # notify_backup "/etc/keepalived/notify.sh backup"
    # notify_fault "/etc/keepalived/notify.sh fault"
    }

## c, backup节点配置keepalived+nginx ##

[root@proxy-c6 ~]# cat /etc/keepalived/keepalived.conf
    global_defs { 
       router_id LVS_DEVEL_161
    }
    
    vrrp_script chk_keep { 
      #script [ 0 -eq 0 ] && exit 0 || exit 1
      #script /tmp/chk_nginx.sh: service nginx status
      script "service nginx status"
      interval 1
      weight -30
    }
    
    vrrp_instance VI_1_test1 { 
        state BACKUP
        interface eth1
        virtual_router_id 51
        priority 90
        advert_int 1
        authentication { 
            auth_type PASS
            auth_pass 1111
        }
        virtual_ipaddress { 
            192.168.56.251
        }
        vrrp_macst_group4 224.0.10.67
        track_script { 
          chk_keep
        }
    # #notify state change
    	notify_master "service nginx start"
    # notify_master "/etc/keepalived/notify.sh master"
    # notify_backup "/etc/keepalived/notify.sh backup"
    # notify_fault "/etc/keepalived/notify.sh fault"
    }

### keepalived的notify状态通知脚本 ###

每个keepalived主机都配置相同脚本: 当keepalived是master状态时，启动haproxy; 否则就停止haproxy  
具体<linux如何发送126邮件>配置见[https://blog.csdn.net/eyeofeagle/article/details/104295051\#c\_action\_39][https_blog.csdn.net_eyeofeagle_article_details_104295051_c_action_39]

[root@proxy-c6 vagrant]# cat /etc/keepalived/notify.sh 
    #!/bin/bash
    #keepalived-master-->启动haproxy
    #keepalived-backup-->停止haproxy
    
    role=$1
    send_mail(){ 
       subject="keepalived master changes"
       context="$(date +'%F %T'): $(hostname) changes to $role "
       echo $context |mailx -s $subject eyeofeagle@126.com root@localhost
    }
    
    ctl_haproxy(){ 
       case $role in 
          master)
            service haproxy start;;
    
          backup|faul)
    	service haproxy stop;;
        esac 
    }
    
    send_mail
    ctl_haproxy

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## d, 测试keepalived ##

[root@proxy-c6 conf.d]# service keepalived start
    Starting keepalived:                                       [  OK  ]
    [root@proxy-c6 conf.d]# ip a |grep 230
        inet 192.168.56.230/32 scope global eth1
        
    [root@proxy-c7 conf.d]# systemctl start keepalived
    [root@proxy-c7 conf.d]# ip a |grep 230
    #访问nginx代理的服务：无论哪个服务器为MASTER，都可以访问
    [root1@c7-docker ~]# curl 192.168.56.251:88
    this is nginx2:82
    
    
    ##ip转移
    [root@proxy-c6 conf.d]# service keepalived stop
    Stopping keepalived:                                       [  OK  ]
    [root@proxy-c6 conf.d]# ip a |grep 230
    [root@proxy-c6 conf.d]# 
    
    [root@proxy-c7 conf.d]# ip a |grep 230
        inet 192.168.56.230/32 scope global eth1
    #访问nginx代理的服务：无论哪个服务器为MASTER，都可以访问
    [root1@proxy-c7-docker ~]# curl 192.168.56.251:88
    this is nginx2:82

# 3, 手动添加/删除：虚拟IP #

## a, Windows cmd管理虚拟ip ##

#添加
    netsh.exe interface ip  add    address name="WLAN" address=192.168.1.40/24 gateway=192.168.1.1 #store=persistent/active
    
    #移除
    netsh.exe interface ip  delete address name="WLAN" address=192.168.1.40
    
    ####################测试，查看ip 
    无线局域网适配器 WLAN:                                                                                                                                  
       连接特定的 DNS 后缀 . . . . . . . :                                         
       本地链接 IPv6 地址. . . . . . . . : fe80::9906:a98b:3081:11b%13            
       IPv4 地址 . . . . . . . . . . . . : 192.168.1.30                       
       子网掩码  . . . . . . . . . . . . : 255.255.255.0                        
       IPv4 地址 . . . . . . . . . . . . : 192.168.1.40                       
       子网掩码  . . . . . . . . . . . . : 255.255.255.0                        
       默认网关. . . . . . . . . . . . . : 192.168.1.1

## b, CentOS 管理虚拟IP ##

### a, 一块网卡，多个ip ###

#### 临时修改：ip addr ####

#添加虚拟ip
    [root@c7-docker ~]# ip addr add 192.168.56.227/24 dev eth1
    [root@c7-docker ~]# ip addr show eth1 
    3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000     
        link/ether 08:00:27:46:0e:44 brd ff:ff:ff:ff:ff:ff                                                    
        inet 192.168.56.117/24 brd 192.168.56.255 scope global noprefixroute eth1                             
           valid_lft forever preferred_lft forever                                                            
        inet 192.168.56.227/24 scope global secondary eth1                                                    
           valid_lft forever preferred_lft forever                                                            
        inet6 fe80::a00:27ff:fe46:e44/64 scope link                                                           
           valid_lft forever preferred_lft forever                                                            
                                                                                                                                                             
    #删除虚拟ip 
    [root@c7-docker ~]# ip addr del 192.168.56.227/24 dev eth1

#### 永久修改：网卡配置文件 ####

[root@c7-docker gitlab]# cat /etc/sysconfig/network-scripts/ifcfg-eth1 
    #VAGRANT-BEGIN 
    # The contents below are automatically generated by Vagrant. Do not modify. 
    NM_CONTROLLED=yes                                                                                               
    BOOTPROTO=none                                                                                                  
    ONBOOT=yes                                                                                                      
    IPADDR=192.168.56.117                                                                                           
    IPADDR2=192.168.56.227                                                                                          
    NETMASK=255.255.255.0                                                                                           
    DEVICE=eth1                                                                                                     
    PEERDNS=no                                                                                                      
    #VAGRANT-END

### b, 一块网卡，多个别名 ###

#### CentOS7: ip addr ####

[root@c7-docker ~]# ip addr add 192.168.56.227/24 dev eth1 label eth1:2
    [root@c7-docker ~]# ip addr show eth1
    3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
        link/ether 08:00:27:46:0e:44 brd ff:ff:ff:ff:ff:ff
        inet 192.168.56.117/24 brd 192.168.56.255 scope global noprefixroute eth1
           valid_lft forever preferred_lft forever
        inet 192.168.56.227/24 scope global secondary eth1:2
           valid_lft forever preferred_lft forever
        inet6 fe80::a00:27ff:fe46:e44/64 scope link
           valid_lft forever preferred_lft forever
    
    [root@c7-docker ~]# ip addr del 192.168.56.227/24 dev eth1 label eth1:2

#### CentOS6: ifconfig 网卡 ####

#添加虚拟ip, 在网卡的别名上
    [root@test-c62 ~]# ifconfig eth1:0 192.168.56.227/24 up 
    [root@test-c62 ~]# ifconfig 
    eth1      Link encap:Ethernet  HWaddr 08:00:27:6D:28:E0                       
              inet addr:192.168.56.162  Bcast:192.168.56.255  Mask:255.255.255.0  
              inet6 addr: fe80::a00:27ff:fe6d:28e0/64 Scope:Link                  
              UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1                  
              RX packets:52592 errors:0 dropped:0 overruns:0 frame:0              
              TX packets:81411 errors:0 dropped:0 overruns:0 carrier:0            
              collisions:0 txqueuelen:1000                                        
              RX bytes:7511647 (7.1 MiB)  TX bytes:17705955 (16.8 MiB)            
                                                                                  
    eth1:0    Link encap:Ethernet  HWaddr 08:00:27:6D:28:E0                       
              inet addr:192.168.56.227  Bcast:192.168.56.255  Mask:255.255.255.0  
              UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1                  
     
    #删除虚拟ip, 在网卡的别名上 
    [root@test-c62 ~]# ifconfig eth1:0 192.168.56.227/24 down

[https_blog.csdn.net_eyeofeagle_article_details_104295051_c_action_39]: https://blog.csdn.net/eyeofeagle/article/details/104295051#c_action_39
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