Keepalived

Keepalived

keepalived 

Keepalived

vrrp协议在Linux主机上以守护进程方式的实现：
能够根据配置文件自动生成ipvs规则：
对各RS做健康状态检测：

yum install -y keepalived
rpm -ql keepalived

配置文件组成部分
GLOBAL CONFIGURATION
VRRPD CONF IGURATION

• vrrp instance
• vrrp synchonization group

LVS CONFIGURATION

HA Cluster配置前提
1、本机的主机名，要与hostname（uname-n）获得的名称保持一致：
CentOS 6：/etc/sysconfig/network CentOS 7：hostnamectl set-hostname HOSTNAME各节点要能互相解析主机名：一般建议通过hosts文件进行解析：

cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
192.168.2.99 node1
192.168.2.100 node2
192.168.2.101 node3 web1
192.168.2.253 node4 web2

2、各节点时间同步：

ntpdate $ntpserverip

3、确保iptables及selipux不会成为服务阻碍

systemctl stop iptable
setenforce 0
sed '/SELINUX/s/=enforcing/permissive/' /etc/selinux/config -i

示例1：keepalived

keepalived

kepalived1 v1 master

配置文件

cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
   notification_email {
    root@localhost #设置报警收件人邮箱  
   }
   notification_email_from keepalived1@localhost #配置发件人
   smtp_server 127.0.0.1 #配置邮件服务器 
   smtp_connect_timeout 30
   router_id node1  //设置路由ID号，一般设置主机名
}

vrrp_script chk_down {  #定义脚本检测
   script "[[-f /etc/keepalived/down]] && exit 1 || exit 0"  #检测文件是否存在，存在返回 1，不存在 0
   interval 1                  #1 秒检测一次
   weight -2                  #失败后权重 - 2
#   fall  2                      #失败判断 2 次
#   rise  1                        #成功判断 1 次
}

vrrp_instance VI_1 {
    state MASTER  #配置模式  主master备bakcup
    interface eno16777728  #vip 绑定接口
    virtual_router_id 10  #在V1_1里面，主辅VRID号必须一致
    priority 100 #配置优先级 值越大优先级就越高
    advert_int 1
    authentication {
        auth_type PASS  #认证
        auth_pass 1000  #认证密码 主辅服务器密码必须一致
    }
    virtual_ipaddress {
        192.168.2.2  #配置虚拟 IP 地址  
    }
    track_script {        #配置执行上面定义的脚本
        chk_down    #上面定义的脚本
    }
    
    notify_master "/etc/keepalived/notify.sh master" #当切换主节点执行    通常用于发邮件通知管理员
    notify_backup "/etc/keepalived/notify.sh backup" #当切换备节点执行
    notify_fault "/etc/keepalived/notify.sh fault" #当切无法连接执行
}

virtual_server 192.168.2.2 80 {  #lvs 配置部分，设置 IP 端口
    delay_loop 6   
    lb_algo wrr                   #设置权重模型
    lb_kind DR                  #DR 模型
    #persistence_timeout 50             #长连接超时
    nat_mask 255.255.255.0   
    protocol TCP                        
    sorry_server 127.0.0.1 80 #增加一行sorry_server，当所有节点挂掉就启用临时页面

    real_server 192.168.2.101 80 { #配置 rs 
        weight 1  
    #          HTTP_GET {          #监控配置   ，通过 HTTP 监控，还有 #ssl,tcp,smtp
    #         url {   
    #         path /        #监控网址
    #         status_code 200      #检测状态码 200
    #        }   
            connect_timeout 2  #检测时长
            nb_get_retry 3   
            delay_before_retry 1   
        }  
        
        TCP_CHECK {        
            connect_timeout 2  #检测时长
     
        }   
    }
    real_server 192.168.2.253 80 { 
        weight 2   
        TCP_CHECK {        
            connect_timeout 2 
        }   
    }

脚本

cat notify.sh 
#!/bin/bash
vip=192.168.2.2
contact='root@localhost'
notify() {
    mailsubject="`hostname` to be $1: $vip floating"
    mailbody="`date'+%F %H:%M:%S'`: vrrp transition, `hostname` changed to be $1"
    echo $mailbody | mail -s "$mailsubject" $contact
}
case "$1" in
    master)
        notify master
#        /etc/rc.d/init.d/haproxy start
        exit 0
    ;;
    backup)
        notify backup
#        /etc/rc.d/init.d/haproxy stop
        exit 0
    ;;
    fault)
        notify fault
#        /etc/rc.d/init.d/haproxy stop
        exit 0
    ;;
    *)
        echo 'Usage: `basename $0` {master|backup|fault}'
        exit 1
    ;;
esac

启动服务

systemctl start keepalived
systemctl enable keepalived
启用SORRYSERVER
echo sorry> /var/www/html/index.html
systemctl start httpd
systemctl enable httpd
可生成随机密码num*2
openssl rand -hex 4

keepalived2 v1 backup
配置文件

cat /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
   notification_email {
        root@localhost
   }
   notification_email_from keepalived2@localhost
   smtp_server 127.0.0.1
   smtp_connect_timeout 30
   router_id node2
}
 
vrrp_script chk_down {
   script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0"
   interval 1
   weight -2
}
 
vrrp_instance VI_1 {
    state BACKUP
    interface eno16777728
    virtual_router_id 51
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1000
    }
    virtual_ipaddress {
        192.168.2.2
    }
    track_script {
        chk_down
    }
 
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
}

virtual_server 192.168.2.253 80 {
    delay_loop 6   
    lb_algo wrr                  
    lb_kind DR                 
    nat_mask 255.255.255.0   
    protocol TCP                        
    sorry_server 127.0.0.1 80

    real_server 192.168.2.101 80 { 
        weight 1   
        TCP_CHECK {        
            connect_timeout 2 
        }   
    }
    real_server 192.168.2.253 80 { 
        weight 2   
        TCP_CHECK {        
            connect_timeout 2 
        }   
    }

脚本和keepalived1一样

启动服务

systemctl start keepalived
systemctl enable keepalived
启用SORRYSERVER
echo sorry> /var/www/html/index.html
systemctl start httpd

web1 web2

systemctl start httpd
cat lo.sh 
#!/bin/bash

VIP=192.168.2.2
#GATEWAY=192.168.3.254

case $1 in
on)
    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}/32 broadcast ${VIP} up
#    route add default gw ${GATEWAY}
    ;;
off)
    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
    ;;
esac

测试

在keepalived查看VIP
ip add 
在keeaplived查看ipvsadm规则
ipvsadm -Ln 
客户端打开浏览器访问
curl http://192.168.2.2/

---

示例2：keepalived+nginx反向代理

keepalived+nginx_proxy

keepalived1 v1 master
配置文件

cat /etc/keepalived/keepalived.conf
! 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 node2
}

vrrp_script chk_down { 
   script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0" 
   interval 1                 
   weight -2                 
}

vrrp_script chk_nginx {
    script "killall -0 nginx &> /dev/null"
    interval 1
    weight -10
}

vrrp_instance VI_1 {
    state MASTER
    interface eno16777728 
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1000
    }
    virtual_ipaddress {
        192.168.2.2
    }
    track_script {       
        chk_down 
    chk_nginx
    }
    
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
}

nginx配置文件

events {
    use epoll;
    worker_connections  51200;
}
http {
      server_tokens off;
    include       mime.types;
    default_type  application/octet-stream;
    log_format  main     '$server_addr $remote_addr [$time_local] $msec+$connection'
                        '"$request" $status $connection $request_time $body_bytes_sent "$http_referer"'
                        '"$http_user_agent" "$http_x_forwarded_for"';
    open_log_file_cache max=1000 inactive=20s min_uses=1 valid=1m;
    access_log /var/log/nginx/access_log main;
    log_not_found on;
    sendfile        on;
    tcp_nopush     on;
    gzip  on;
    gzip_comp_level 6;
    keepalive_timeout  35;
    upstream webs {
    server 192.168.2.101 weight=1;
    server 192.168.2.253 weight=2;
}

    server{
          location / {
        proxy_pass http://webs/;
          }
 		
     }
        
}

keepalived2 v1 bakcup

cat /etc/keepalived/keepalived.conf
! 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 node2
}

vrrp_script chk_down { 
   script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0" 
   interval 1                 
   weight -2                 
}

vrrp_script chk_nginx {
    script "killall -0 nginx &> /dev/null"
    interval 1
    weight -10
}

vrrp_instance VI_1 {
    state BACKUP
    interface eno16777728 
    virtual_router_id 51
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1000
    }
    virtual_ipaddress {
        192.168.2.2
    }
    track_script {       
        chk_down 
    chk_nginx
    }
    
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
}

nginx配置文件与keepalived2一样

web1 web2

bash lo.sh off
systemctl restart httpd

测试

客户端curl http://192.168.2.2/
curl -I 192.168.2.2|grep nginx
curl -I 192.168.2.253|grep Apache

示例3：双主模型

keepalived2

keepalived1 v1 master v2 bakcup
主配置文件

cat /etc/keepalived/keepalived.conf
! 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 node2
}

vrrp_script chk_down { 
   script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0" 
   interval 1                 
   weight -2                 
}

vrrp_script chk_nginx {
    script "killall -0 nginx &> /dev/null"  #判断NGINX服务是否正在运行
    interval 1
    weight -10
}

vrrp_instance VI_1 {
    state MASTER
    interface eno16777728 
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1000
    }
    virtual_ipaddress {
        192.168.2.2
    }
    track_script {       
        chk_down 
    chk_nginx
    }
    
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
}

vrrp_instance VI_2 {
    state BACKUP
    interface eno16777728 
    virtual_router_id 52
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 10001
    }
    virtual_ipaddress {
        192.168.2.3
    }
    track_script {       
        chk_down 
    chk_nginx
    }
    
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
}

keepalived2 v1 bakcup v1 master
主配置文件

cat /etc/keepalived/keepalived.conf
! 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 node2
}

vrrp_script chk_down { 
   script "[[ -f /etc/keepalived/down ]] && exit 1 || exit 0" 
   interval 1                 
   weight -2                 
}

vrrp_script chk_nginx {
    script "killall -0 nginx &> /dev/null"
    interval 1
    weight -10
}

vrrp_instance VI_1 {
    state BACKUP
    interface eno16777728 
    virtual_router_id 51
    priority 99
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1000
    }
    virtual_ipaddress {
        192.168.2.2
    }
    track_script {       
        chk_down 
    chk_nginx
    }
    
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
}

vrrp_instance VI_2{
    state MASTER
    interface eno16777728 
    virtual_router_id 52
    priority 101
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 10001
    }
    virtual_ipaddress {
        192.168.2.3
    }
    track_script {       
        chk_down 
    chk_nginx
    }
    
    notify_master "/etc/keepalived/notify.sh master"
    notify_backup "/etc/keepalived/notify.sh backup"
    notify_fault "/etc/keepalived/notify.sh fault"
}

测试

keepalived1和2使用 ip addr 查看下VIP
客户端测试
curl http://192.168.2.2
curl http://192.168.2.3