Keepalived搭建主从架构、主主架构实例

实例拓扑图：

DR1和DR2部署Keepalived和lvs作主从架构或主主架构，RS1和RS2部署nginx搭建web站点。

注意：各节点的时间需要同步（ntpdate ntp1.aliyun.com）；关闭firewalld（systemctl stop firewalld.service，systemctl disable firewalld.service），设置selinux为permissive（setenforce 0）；同时确保DR1和DR2节点的网卡支持MULTICAST（多播）通信。通过命令ifconfig可以查看到是否开启了MULTICAST：

       

Keepalived的主从架构

搭建RS1：

[root@RS1 ~]# yum -y install nginx   #安装nginx
[root@RS1 ~]# vim /usr/share/nginx/html/index.html   #修改主页
    <h1> 192.168.4.118 RS1 server </h1>
[root@RS1 ~]# systemctl start nginx.service   #启动nginx服务
[root@RS1 ~]# vim RS.sh   #配置lvs-dr的脚本文件
    #!/bin/bash
    #
    vip=192.168.4.120
    mask=255.255.255.255
    case $1 in
    start)
        echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore
        echo 1 > /proc/sys/net/ipv4/conf/lo/arp_ignore
        echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce
        echo 2 > /proc/sys/net/ipv4/conf/lo/arp_announce
        ifconfig lo:0 $vip netmask $mask broadcast $vip up
        route add -host $vip dev lo:0
        ;;
    stop)
        ifconfig lo:0 down
        echo 0 > /proc/sys/net/ipv4/conf/all/arp_ignore
        echo 0 > /proc/sys/net/ipv4/conf/lo/arp_ignore
        echo 0 > /proc/sys/net/ipv4/conf/all/arp_announce
        echo 0 > /proc/sys/net/ipv4/conf/lo/arp_announce
        ;;
    *) 
        echo "Usage $(basename $0) start|stop"
        exit 1
        ;;
    esac
[root@RS1 ~]# bash RS.sh start

参考RS1的配置搭建RS2。

搭建DR1：

[root@DR1 ~]# yum -y install ipvsadm keepalived   #安装ipvsadm和keepalived
[root@DR1 ~]# vim /etc/keepalived/keepalived.conf   #修改keepalived.conf配置文件
    global_defs {
       notification_email {
         root@localhost
       }
       notification_email_from keepalived@localhost
       smtp_server 127.0.0.1
       smtp_connect_timeout 30
       router_id 192.168.4.116
       vrrp_skip_check_adv_addr
       vrrp_mcast_group4 224.0.0.10
    }
    
    vrrp_instance VIP_1 {
        state MASTER
        interface eno16777736
        virtual_router_id 1
        priority 100
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass %&hhjj99
        }
        virtual_ipaddress {
        　　192.168.4.120/24 dev eno16777736 label eno16777736:0
        }
    }
    
    virtual_server 192.168.4.120 80 {
        delay_loop 6
        lb_algo rr
        lb_kind DR
        protocol TCP
    
        real_server 192.168.4.118 80 {
            weight 1
            HTTP_GET {
                url {
                  path /index.html
                  status_code 200
                }
                connect_timeout 3
                nb_get_retry 3
                delay_before_retry 3
            }
        }
        real_server 192.168.4.119 80 {
            weight 1
            HTTP_GET {
                url {
                  path /index.html
                  status_code 200
                }
                connect_timeout 3
                nb_get_retry 3
                delay_before_retry 3
            }
        }
    }
[root@DR1 ~]# systemctl start keepalived
[root@DR1 ~]# ifconfig
    eno16777736: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 192.168.4.116  netmask 255.255.255.0  broadcast 192.168.4.255
            inet6 fe80::20c:29ff:fe93:270f  prefixlen 64  scopeid 0x20<link>
            ether 00:0c:29:93:27:0f  txqueuelen 1000  (Ethernet)
            RX packets 14604  bytes 1376647 (1.3 MiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 6722  bytes 653961 (638.6 KiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    eno16777736:0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 192.168.4.120  netmask 255.255.255.0  broadcast 0.0.0.0
            ether 00:0c:29:93:27:0f  txqueuelen 1000  (Ethernet)
[root@DR1 ~]# ipvsadm -ln
    IP Virtual Server version 1.2.1 (size=4096)
    Prot LocalAddress:Port Scheduler Flags
      -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
    TCP  192.168.4.120:80 rr
      -> 192.168.4.118:80             Route   1      0          0         
      -> 192.168.4.119:80             Route   1      0          0

DR2的搭建基本同DR1，主要修改一下配置文件中/etc/keepalived/keepalived.conf的state和priority：state BACKUP、priority 90. 同时我们发现作为backup的DR2没有启用eno16777736:0的网口：

客户端进行测试：

[root@client ~]# for i in {1..20};do curl http://192.168.4.120;done   #客户端正常访问
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>

[root@DR1 ~]# systemctl stop keepalived.service   #关闭DR1的keepalived服务

[root@DR2 ~]# systemctl status keepalived.service   #观察DR2，可以看到DR2已经进入MASTER状态
● keepalived.service - LVS and VRRP High Availability Monitor
   Loaded: loaded (/usr/lib/systemd/system/keepalived.service; disabled; vendor preset: disabled)
   Active: active (running) since Tue 2018-09-04 11:33:04 CST; 7min ago
  Process: 12983 ExecStart=/usr/sbin/keepalived $KEEPALIVED_OPTIONS (code=exited, status=0/SUCCESS)
 Main PID: 12985 (keepalived)
   CGroup: /system.slice/keepalived.service
           ├─12985 /usr/sbin/keepalived -D
           ├─12988 /usr/sbin/keepalived -D
           └─12989 /usr/sbin/keepalived -D

Sep 04 11:37:41 happiness Keepalived_healthcheckers[12988]: SMTP alert successfully sent.
Sep 04 11:40:22 happiness Keepalived_vrrp[12989]: VRRP_Instance(VIP_1) Transition to MASTER STATE
Sep 04 11:40:23 happiness Keepalived_vrrp[12989]: VRRP_Instance(VIP_1) Entering MASTER STATE
Sep 04 11:40:23 happiness Keepalived_vrrp[12989]: VRRP_Instance(VIP_1) setting protocol VIPs.
Sep 04 11:40:23 happiness Keepalived_vrrp[12989]: Sending gratuitous ARP on eno16777736 for 192.168.4.120
Sep 04 11:40:23 happiness Keepalived_vrrp[12989]: VRRP_Instance(VIP_1) Sending/queueing gratuitous ARPs on eno16777736 for 192.168.4.120
Sep 04 11:40:23 happiness Keepalived_vrrp[12989]: Sending gratuitous ARP on eno16777736 for 192.168.4.120
Sep 04 11:40:23 happiness Keepalived_vrrp[12989]: Sending gratuitous ARP on eno16777736 for 192.168.4.120
Sep 04 11:40:23 happiness Keepalived_vrrp[12989]: Sending gratuitous ARP on eno16777736 for 192.168.4.120
Sep 04 11:40:23 happiness Keepalived_vrrp[12989]: Sending gratuitous ARP on eno16777736 for 192.168.4.120

[root@client ~]# for i in {1..20};do curl http://192.168.4.120;done   #可以看到客户端正常访问
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>
<h1> 192.168.4.119 RS2 server</h1>
<h1> 192.168.4.118 RS1 server </h1>

Keepalived的主主架构

 修改RS1和RS2，添加新的VIP：

[root@RS1 ~]# cp RS.sh RS_bak.sh
[root@RS1 ~]# vim RS_bak.sh   #添加新的VIP
    #!/bin/bash
    #
    vip=192.168.4.121
    mask=255.255.255.255
    case $1 in
    start)
        echo 1 > /proc/sys/net/ipv4/conf/all/arp_ignore
        echo 1 > /proc/sys/net/ipv4/conf/lo/arp_ignore
        echo 2 > /proc/sys/net/ipv4/conf/all/arp_announce
        echo 2 > /proc/sys/net/ipv4/conf/lo/arp_announce
        ifconfig lo:1 $vip netmask $mask broadcast $vip up
        route add -host $vip dev lo:1
        ;;
    stop)
        ifconfig lo:1 down
        echo 0 > /proc/sys/net/ipv4/conf/all/arp_ignore
        echo 0 > /proc/sys/net/ipv4/conf/lo/arp_ignore
        echo 0 > /proc/sys/net/ipv4/conf/all/arp_announce
        echo 0 > /proc/sys/net/ipv4/conf/lo/arp_announce
        ;;
    *)
        echo "Usage $(basename $0) start|stop"
        exit 1
        ;;
    esac
[root@RS1 ~]# bash RS_bak.sh start
[root@RS1 ~]# ifconfig
    ...
    lo:0: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 192.168.4.120  netmask 255.255.255.255
            loop  txqueuelen 0  (Local Loopback)
    
    lo:1: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 192.168.4.121  netmask 255.255.255.255
            loop  txqueuelen 0  (Local Loopback) 
[root@RS1 ~]# scp RS_bak.sh root@192.168.4.119:~
root@192.168.4.119's password: 
RS_bak.sh                100%  693     0.7KB/s   00:00

[root@RS2 ~]# bash RS_bak.sh   #直接运行脚本添加新的VIP 
[root@RS2 ~]# ifconfig
    ...
    lo:0: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 192.168.4.120  netmask 255.255.255.255
            loop  txqueuelen 0  (Local Loopback)
    
    lo:1: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
            inet 192.168.4.121  netmask 255.255.255.255
            loop  txqueuelen 0  (Local Loopback)

修改DR1和DR2：

[root@DR1 ~]# vim /etc/keepalived/keepalived.conf   #修改DR1的配置文件，添加新的实例，配置服务器组
    ...
    vrrp_instance VIP_2 {
        state BACKUP
        interface eno16777736
        virtual_router_id 2
        priority 90
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass UU**99^^
        }
        virtual_ipaddress {
            192.168.4.121/24 dev eno16777736 label eno16777736:1
        }
    }
    
    virtual_server_group ngxsrvs {
        192.168.4.120 80
        192.168.4.121 80
    }
    virtual_server group ngxsrvs {
        ...
    }
[root@DR1 ~]# systemctl restart keepalived.service   #重启服务
[root@DR1 ~]# ifconfig   #此时可以看到eno16777736:1，因为DR2还未配置
    eno16777736: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 192.168.4.116  netmask 255.255.255.0  broadcast 192.168.4.255
            inet6 fe80::20c:29ff:fe93:270f  prefixlen 64  scopeid 0x20<link>
            ether 00:0c:29:93:27:0f  txqueuelen 1000  (Ethernet)
            RX packets 54318  bytes 5480463 (5.2 MiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 38301  bytes 3274990 (3.1 MiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    eno16777736:0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 192.168.4.120  netmask 255.255.255.0  broadcast 0.0.0.0
            ether 00:0c:29:93:27:0f  txqueuelen 1000  (Ethernet)
    
    eno16777736:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 192.168.4.121  netmask 255.255.255.0  broadcast 0.0.0.0
            ether 00:0c:29:93:27:0f  txqueuelen 1000  (Ethernet)
[root@DR1 ~]# ipvsadm -ln
    IP Virtual Server version 1.2.1 (size=4096)
    Prot LocalAddress:Port Scheduler Flags
      -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
    TCP  192.168.4.120:80 rr
      -> 192.168.4.118:80             Route   1      0          0         
      -> 192.168.4.119:80             Route   1      0          0         
    TCP  192.168.4.121:80 rr
      -> 192.168.4.118:80             Route   1      0          0         
      -> 192.168.4.119:80             Route   1      0          0

[root@DR2 ~]# vim /etc/keepalived/keepalived.conf   #修改DR2的配置文件，添加实例，配置服务器组
    ...
    vrrp_instance VIP_2 {
        state MASTER
        interface eno16777736
        virtual_router_id 2
        priority 100
        advert_int 1
        authentication {
            auth_type PASS
            auth_pass UU**99^^
        }
        virtual_ipaddress {
            192.168.4.121/24 dev eno16777736 label eno16777736:1
        }
    }
    
    virtual_server_group ngxsrvs {
        192.168.4.120 80
        192.168.4.121 80
    }
    virtual_server group ngxsrvs {
        ...
    }
[root@DR2 ~]# systemctl restart keepalived.service   #重启服务
[root@DR2 ~]# ifconfig
    eno16777736: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 192.168.4.117  netmask 255.255.255.0  broadcast 192.168.4.255
            inet6 fe80::20c:29ff:fe3d:a31b  prefixlen 64  scopeid 0x20<link>
            ether 00:0c:29:3d:a3:1b  txqueuelen 1000  (Ethernet)
            RX packets 67943  bytes 6314537 (6.0 MiB)
            RX errors 0  dropped 0  overruns 0  frame 0
            TX packets 23250  bytes 2153847 (2.0 MiB)
            TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
    
    eno16777736:1: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
            inet 192.168.4.121  netmask 255.255.255.0  broadcast 0.0.0.0
            ether 00:0c:29:3d:a3:1b  txqueuelen 1000  (Ethernet)
[root@DR2 ~]# ipvsadm -ln
    IP Virtual Server version 1.2.1 (size=4096)
    Prot LocalAddress:Port Scheduler Flags
      -> RemoteAddress:Port           Forward Weight ActiveConn InActConn
    TCP  192.168.4.120:80 rr
      -> 192.168.4.118:80             Route   1      0          0         
      -> 192.168.4.119:80             Route   1      0          0         
    TCP  192.168.4.121:80 rr
      -> 192.168.4.118:80             Route   1      0          0         
      -> 192.168.4.119:80             Route   1      0          0 

客户端测试：

[root@client ~]# for i in {1..20};do curl http://192.168.4.120;done
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
[root@client ~]# for i in {1..20};do curl http://192.168.4.121;done
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>
    <h1> 192.168.4.119 RS2 server</h1>
    <h1> 192.168.4.118 RS1 server </h1>