keepalived virtual_ipaddress 详解 keepalived 虚拟ip原理

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mob6454cc620c34 2024-05-03 13:27:31

文章标签 php 运维 shell IP 服务器 文章分类 运维

内容

1、vrrp协议简介

2、keepalived的工作架构以及工作原理

3、keepalived的安装使用详解

一、vrrp协议简介

(5) Backup 路由器的优先级高于Master 路由器时，由Backup 路由器的工作方式（抢占方式和非抢占方式）决定是否重新选举Master。

二、keepalived简介

三、keepalived的安装以及配置

[root@localhost ~]# yum info keepalived
Loaded plugins: fastestmirror, security
Loading mirror speeds from cached hostfile
base                                                                                              | 4.0 kB     00:00 ... 
Available Packages
Name        : keepalived
Arch        : x86_64
Version     : 1.2.13
Release     : 5.el6_6
Size        : 214 k
Repo        : base
Summary     : Load balancer and high availability service
URL         : http://www.keepalived.org/
License     : GPLv2+
Description : Keepalived provides simple and robust facilities for load balancing
            : and high availability.  The load balancing framework relies on the
            : well-known and widely used Linux Virtual Server (IPVS) kernel module
            : providing layer-4 (transport layer) load balancing.  Keepalived
            : implements a set of checkers to dynamically and adaptively maintain
            : and manage a load balanced server pool according their health.
            : Keepalived also implements the Virtual Router Redundancy Protocol
            : (VRRPv2) to achieve high availability with director failover.

配置文件：/etc/keepalived/keepalived.conf

主程序：/usr/sbin/keepalived

! Configuration File for keepalived #注释内容
global_defs { #表示keepalived在发生诸如切换操作时需要发送email通知，以及email发送给哪些邮件地址，邮件地址可以多个，每行一个
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc #表示发送通知邮件时邮件源地址是谁
   smtp_server 192.168.200.1 #表示发送email时使用的smtp服务器地址
   smtp_connect_timeout 30 #连接smtp连接超时时间
   router_id LVS_DEVEL #机器标识，相当于主机名
}

vrrp_instance VI_1 {  #VI_1表示这个VRRP的虚拟路由器的名字
    state MASTER #状态值
    interface eth0 #监听的端口
    virtual_router_id 51  #VRID，这个必须与备节点是一样
    priority 100 #优先级
    advert_int 1 #检测间隔
    authentication { #认证
        auth_type PASS #帐号
        auth_pass 1111 #密码
    }
    virtual_ipaddress { #需要虚拟的IP地址，可以是多个
        192.168.200.16
        192.168.200.17
        192.168.200.18
    }
}

virtual_server 192.168.200.100 80 { # 设置VIP的IP和端口信息
    delay_loop 6 #检测间隔时间
    lb_algo rr #调度算法
    lb_kind NAT #lvs类型
    nat_mask 255.255.255.0 #NAT类型的网关掩码，其他类型不需要此项
    persistence_timeout 50 #持久连接时间
    protocol TCP #TCP协议
    real_server 192.168.201.100 80 { #RIP的IP和端口
        weight 1 #权重
            url { 
              path /mrtg/  #健康检查，这里是对web服务的检测，有两种方法，一种是指定页面的hash值。一个是页面的状态码，这里是hash值
              digest 9b3a0c85a887a256d6939da88aabd8cd #hash值
            }
            connect_timeout 3 #失败时连接的时间
            nb_get_retry 3 #失败时检测的次数
            delay_before_retry 3 #每次失败等多少秒再进行检查
        }
    }
}

1、单实例（没用启用LVS）

[root@localhost keepalived]# cat keepalived.conf
! Configuration File for keepalived
global_defs {
   notification_email {
root@localhost
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id test1
   vrrp_mcast_group4 224.0.24.122
}
vrrp_instance VI_1 {
    state MASTER
    interface eth0
    virtual_router_id 23
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 12345
    }
    virtual_ipaddress {
        192.168.200.16/24 dev eth0 label eth0:1 
    }
}

BACKUP主机的配置：

[root@php ~]# cat /etc/keepalived/keepalived.conf 
! Configuration File for keepalived
global_defs {
   notification_email {
root@localhost
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id test2
   vrrp_mcast_group4 224.0.24.122
}
vrrp_instance VI_1 {
    state BACKUP
    interface eth1
    virtual_router_id 23
    priority 90
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 12345
    }
    virtual_ipaddress {
        192.168.200.16/24 dev eth1 label eth1:1 
    }
}

[root@localhost keepalived]# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:0C:29:DA:A5:4C  
          inet addr:10.1.252.36  Bcast:10.1.255.255  Mask:255.255.0.0
          inet6 addr: fe80::20c:29ff:feda:a54c/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:18767 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1302 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:1646398 (1.5 MiB)  TX bytes:184756 (180.4 KiB)
eth0:1    Link encap:Ethernet  HWaddr 00:0C:29:DA:A5:4C  
          inet addr:192.168.200.16  Bcast:0.0.0.0  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:2 errors:0 dropped:0 overruns:0 frame:0
          TX packets:2 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:202 (202.0 b)  TX bytes:202 (202.0 b)
[root@localhost keepalived]# tail /var/log/messages
Oct 31 19:43:16 localhost Keepalived_healthcheckers[2629]: Opening file '/etc/keepalived/keepalived.conf'.
Oct 31 19:43:16 localhost Keepalived_healthcheckers[2629]: Configuration is using : 7453 Bytes
Oct 31 19:43:16 localhost Keepalived_healthcheckers[2629]: Using LinkWatch kernel netlink reflector...
Oct 31 19:43:16 localhost Keepalived_vrrp[2630]: VRRP_Instance(VI_1) Transition to MASTER STATE
Oct 31 19:43:16 localhost Keepalived_vrrp[2630]: VRRP_Instance(VI_1) Received lower prio advert, forcing new election
Oct 31 19:43:17 localhost Keepalived_vrrp[2630]: VRRP_Instance(VI_1) Entering MASTER STATE
Oct 31 19:43:17 localhost Keepalived_vrrp[2630]: VRRP_Instance(VI_1) setting protocol VIPs.
Oct 31 19:43:17 localhost Keepalived_vrrp[2630]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.200.16
Oct 31 19:43:17 localhost Keepalived_healthcheckers[2629]: Netlink reflector reports IP 192.168.200.16 added
Oct 31 19:43:22 localhost Keepalived_vrrp[2630]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth0 for 192.168.200.16

MATER：

[root@localhost keepalived]# service  keepalived stop
Stopping keepalived:                                       [  OK  ]
BACKUP：
[root@php ~]# ifconfig
eth1      Link encap:Ethernet  HWaddr 00:0C:29:DE:83:7F  
          inet addr:10.1.249.30  Bcast:10.1.255.255  Mask:255.255.0.0
          inet6 addr: fe80::20c:29ff:fede:837f/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:19877 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1140 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:1743327 (1.6 MiB)  TX bytes:150564 (147.0 KiB)
eth1:1    Link encap:Ethernet  HWaddr 00:0C:29:DE:83:7F  
          inet addr:192.168.200.16  Bcast:0.0.0.0  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:65536  Metric:1
          RX packets:4 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:252 (252.0 b)  TX bytes:252 (252.0 b)
[root@php ~]# !tai
tail /var/log/messages
Nov  1 03:43:15 php Keepalived_vrrp[2530]: VRRP_Instance(VI_1) Received higher prio advert
Nov  1 03:43:15 php Keepalived_vrrp[2530]: VRRP_Instance(VI_1) Entering BACKUP STATE
Nov  1 03:43:15 php Keepalived_vrrp[2530]: VRRP_Instance(VI_1) removing protocol VIPs.
Nov  1 03:43:15 php Keepalived_healthcheckers[2529]: Netlink reflector reports IP 192.168.200.16 removed
Nov  1 03:47:15 php Keepalived_vrrp[2530]: VRRP_Instance(VI_1) Transition to MASTER STATE
Nov  1 03:47:16 php Keepalived_vrrp[2530]: VRRP_Instance(VI_1) Entering MASTER STATE
Nov  1 03:47:16 php Keepalived_vrrp[2530]: VRRP_Instance(VI_1) setting protocol VIPs.
Nov  1 03:47:16 php Keepalived_vrrp[2530]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth1 for 192.168.200.16
Nov  1 03:47:16 php Keepalived_healthcheckers[2529]: Netlink reflector reports IP 192.168.200.16 added
Nov  1 03:47:21 php Keepalived_vrrp[2530]: VRRP_Instance(VI_1) Sending gratuitous ARPs on eth1 for 192.168.200.16

vrrp_instance VI_1 {
    state BACKUP
    interface eth1
    virtual_router_id 23
    priority 90
    advert_int 1
notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
    authentication {
        auth_type PASS
        auth_pass 12345
    }
    virtual_ipaddress {
        192.168.200.16/24 dev eth1 label eth1:1 
    }
}
notify.sh脚本内容如下：
#!/bin/bash
#
contact='root@localhost'
notify() {
mailsubject="$(hostname) to be $1, vip floating"
mailbody="$(date +'%F %T'): vrrp transition, $(hostname) changed to be $1"
echo "$mailbody" | mail -s "$mailsubject" $contact
}
case $1 in
master)
notify master
;;
backup)
notify backup
;;
fault)
notify fault
;;
*)
echo "Usage: $(basename $0) {master|backup|fault}"
exit 1
;;
esac

双实例或多实例的配置过程大同小异，这里就不再进行演示

real_server <IPADDR> <PORT>
{
 weight <INT>
 notify_up <STRING>|<QUOTED-STRING>
 notify_down <STRING>|<QUOTED-STRING>
 HTTP_GET|SSL_GET|TCP_CHECK|SMTP_CHECK|MISC_CHECK { ... }：定义当前主机的健康状态检测方法；
}
HTTP_GET|SSL_GET {
url {
path <URL_PATH>：定义要监控的URL；
status_code <INT>：判断上述检测机制为健康状态的响应码；
digest <STRING>：判断上述检测机制为健康状态的响应的内容的校验码；
}
nb_get_retry <INT>：重试次数；
delay_before_retry <INT>：重试之前的延迟时长；
connect_ip <IP ADDRESS>：向当前RS的哪个IP地址发起健康状态检测请求
connect_port <PORT>：向当前RS的哪个PORT发起健康状态检测请求
bindto <IP ADDRESS>：发出健康状态检测请求时使用的源地址；
bind_port <PORT>：发出健康状态检测请求时使用的源端口；
connect_timeout <INTEGER>：连接请求的超时时长；
}
 TCP_CHECK {
connect_ip <IP ADDRESS>：向当前RS的哪个IP地址发起健康状态检测请求
connect_port <PORT>：向当前RS的哪个PORT发起健康状态检测请求
bindto <IP ADDRESS>：发出健康状态检测请求时使用的源地址；
bind_port <PORT>：发出健康状态检测请求时使用的源端口；
connect_timeout <INTEGER>：连接请求的超时时长；
}

用法：

vrrp_script：定义一个资源监控脚本；
vrrp_script  <STRING> {
script ""
interval INT 
weight -INT 
}
track_script：调用定义的资源监控脚本；
track_script {
SCRIPT_NAME
}

示例：

! Configuration File for keepalived
global_defs {
notification_email {
root@localhost
}
notification_email_from keepalived@localhost
smtp_server 127.0.0.1
smtp_connect_timeout 30
router_id node1
vrrp_mcast_group4 224.0.100.18
}
vrrp_script chk_down { #如果/etc/keepalived/down文件存在，优先级-5
script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"
interval 1
weight -5
}
vrrp_script chk_httpd {#如果httpd服务进程失效，优先级-5
script "killall -0 httpd && exit 0 || exit 1" 
interval 1
weight -5
}
vrrp_instance VI_1 {
state MASTER
interface eno16777736
virtual_router_id 57
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass 98181111
}
virtual_ipaddress {
172.16.100.71/32 dev eno16777736
}
track_script {  #调用脚本
chk_down
chk_httpd
}
notify_master "/etc/keepalived/notify.sh master"
notify_backup "/etc/keepalived/notify.sh backup"
notify_fault "/etc/keepalived/notify.sh fault"
}

好了，keepalived的基本用法就介绍到这里。

转载于:https://blog.51cto.com/6638225/1867848

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