[系统运维]Nginx-keepalived双机热备集群

Nginx服务器安装部署详细步骤（多次安装，过程详细）

离线安裝keepalived

Centos7离线安装和配置Keepalived
链接：https://pan.baidu.com/s/1x7ucXNyOt9sB-M6r8x7_bw
提取码：ok3o

在线安装keepalived

# 安装依赖包
yum install -y curl gcc openssl-devel libnl3-devel net-snmp-devel
# 安装keepalived
yum install -y keepalived

卸载keepalived

keepalived 安装与卸载
Linux下卸载keepalived

# 进入自己的安装目录
cd /usr/local/src/keepalived

# 执行卸载命令
make uninstall

# 找到所有的keepalived文件
whereis keepalived

# 执行 rm -rf 命令挨个删除

keepalived基础命令

# 开机?启动
systemctl enable keepalived 
# 启动
systemctl start keepalived 
# 暂停
systemctl stop keepalived 
# 重启
systemctl restart keepalived 
# 查看状态
systemctl status keepalived
# 查看keepalived日志
tail -f /var/log/messages

keepalived配置虚拟ip

Nginx配置——搭建 Nginx 高可用集群（双机热备）
安装完成之后, 在 /etc/keepalived 目录下有keepalived的配置文件

cat /etc/keepalived/keepalived.conf 

global_defs 配置下，删除掉vrrp_strict配置
state ：主节点为MASTER，备节点为BACKUP
interface ：需要绑定的?卡（可以通过ifconfig查看，我的是ens33）
priority ：主节点配置成100，备节点配置成99
virtual_ipaddress ： 虚拟IP，两个节点需要相同

global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.200.1
   smtp_connect_timeout 30
   router_id LVS_DEVEL  # 通过它，可以访问到主机，在hosts文件中，要做映射关系，类似于 127.0.0.1 LVS_DEVEL
   vrrp_skip_check_adv_addr
   vrrp_strict 	# 删除这句
   vrrp_garp_interval 0
   vrrp_gna_interval 0
}

vrrp_instance VI_1 {
    state MASTER 	# 现在MASTER是主机, 如果是从机要换成 BACKUP
    interface eth0 	# 把eth0 换成自己服务器的网卡
    virtual_router_id 51 	# 主、备机的 virtual_router_id 必须相同
    priority 100 	# 主节点配置成100，备节点配置成99 ,  主、备机取不同的优先级，主机值较大，备份机值较小
    advert_int 1 	# #每隔一秒发送一次心跳，确保从服务器是否还活着
    authentication {
        auth_type PASS
        auth_pass 1111	# 心跳检测需要的密码
    }
    virtual_ipaddress { # 要虚拟的地址
        192.168.200.16
        192.168.200.17
        192.168.200.18
    }
}

获取interface值, (自己服务器的网卡) 可以通过 ip a 命令

ip a

绑定Nginx进程和Keepalived服务

在路径/usr/local/src/ 下新建检测脚本 nginx_check.sh

#! /bin/bash
A=`ps -C nginx -no-header | wc - 1`
if [ $A -eq 0];then
	/usr/local/nginx/sbin/nginx  #自己nginx的安装目录
	sleep 2
	if [`ps -C nginx --no-header| wc -1` -eq 0 ];then
		killall keepalived
	fi
fi

修改keepalived配置文件, 然后重启keepalived服务

vim /etc/keepalived/keepalived.conf 

! Configuration File for keepalived

global_defs {
   notification_email {
     acassen@firewall.loc
     failover@firewall.loc
     sysadmin@firewall.loc
   }
   notification_email_from Alexandre.Cassen@firewall.loc
   smtp_server 192.168.20.61
   smtp_connect_timeout 30
   router_id LVS_DEVEL
   vrrp_skip_check_adv_addr
   vrrp_garp_interval 0
   vrrp_gna_interval 0
}

# 添加这一段检测脚本配置
vrrp_script chk_http_ port {
	script "/usr/local/src/nginx_check.sh"
	interval 2   # (检测脚本执行的间隔)2s
	weight 2  #权重，如果这个脚本检测为真，服务器权重+2
}

vrrp_instance VI_1 {
    state MASTER
    interface ens160
    virtual_router_id 51
    priority 100
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass 1111
    }
    virtual_ipaddress {
        192.168.200.16
    }
}