centos7中安装和配置nginx和keepalived

一.Linux安装nginx

1.安装依赖

yum -y install gcc zlib zlib-devel pcre-devel openssl openssl-devel

2.创建一个文件夹

cd /usr/local
mkdir nginx
cd nginx

3.将nginx安装包放在nginx文件夹下并解压

或者使用wget联网下载

wget http://nginx.org/download/nginx-1.16.1.tar.gz
tar -xvf nginx-1.16.1.tar.gz

4.编译并make

cd nginx-1.16.1
./configure --prefix=/usr/local/naginx
make
make install

常用命令

 #启动
/usr/local/nginx/sbin/nginx  
#修改配置文件重新加载
/usr/local/nginx/sbin/nginx  -s reload  
#关闭
/usr/local/nginx/sbin/nginx

二:安装Keepalived

1.联网下载到/usr/local目录下并解压

有可能会提示连接不成功,加上它提示的命令再下载就好了

cd /usr/local
wget http://www.keepalived.org/software/keepalived-1.4.2.tar.gz

tar zxvf keepalived-1.4.2.tar.gz

2.安装相关依赖,有不用下载了

yum install -y gcc openssl-devel popt-devel

3.编译

cd keepalived-1.4.2

./configure --prefix=/usr/local/keepalived

make

make install

4.相关配置,复制就完了

cp /usr/local/keepalived-1.4.2/keepalived/etc/init.d/keepalived /etc/init.d/

mkdir /etc/keepalived

cp /usr/local/keepalived/etc/keepalived/keepalived.conf /etc/keepalived/

cp /usr/local/keepalived-1.4.2/keepalived/etc/sysconfig/keepalived /etc/sysconfig/

cp /usr/local/keepalived/sbin/keepalived /usr/sbin/

使用keepalived保证nginx的高可用(一主一从)

我的主服务器ip为(192.168.118.3),从机(192.168.118.5)

在两条服务器分别安装nginx和keepalived,

修改keeplived.conf文件

vim /etc/keepalived/keepalived.conf

主机配置文件

! Configuration File for keepalived

global_defs {
    #一个没重复的名字即可
    router_id LVS_DEVEL        
}

# 检测nginx是否运行
vrrp_script chk_nginx {
        script "/etc/keepalived/nginx_check.sh"
        interval 2
#权重减少20,减少完要比从机的值小
        weight -20
}

vrrp_instance VI_1 {

    # MASTER代表主机
    state MASTER

    # 网卡名字  ip addr 可以查看
    interface eno16777736

    # 同一个keepalived集群的virtual_router_id相同
    virtual_router_id 51

    # 权重，master要大于slave
    priority 100

    # 主备通讯时间间隔
    advert_int 1

    # 如果两节点的上联交换机禁用了组播，则采用vrrp单播通告的方式
    # 本机ip
    unicast_src_ip 192.168.118.3
    unicast_peer {
        # 其他机器ip
        192.168.118.5
    }

    # 设置nopreempt防止抢占资源
    nopreempt

    # 主备保持一致
    authentication {
        auth_type PASS
        auth_pass 1111
    }

    # 与上方nginx运行状况检测呼应
    track_script {
        chk_nginx
    }

    virtual_ipaddress {
        # 虚拟ip地址（VIP，一个尚未占用的内网ip即可）
        192.168.118.118
    }
}

从机配置文! Configuration File for keepalived

global_defs {
    #一个没重复的名字即可
    router_id LVS_DEVEL
}

# 检测nginx是否运行
vrrp_script chk_nginx {
        script "/etc/keepalived/nginx_check.sh"
        interval 2

        weight -20   
}

vrrp_instance VI_1 {

    # 代表是从机
    state BACKUP

    # 网卡名字，ip addr获取
    interface eno16777736

    # 同一个keepalived集群的virtual_router_id相同
    virtual_router_id 51

    # 权重，master要大于slave
    priority 90

    # 主备通讯时间间隔
    advert_int 1

    # 如果两节点的上联交换机禁用了组播，则采用vrrp单播通告的方式
    # 本机ip
    unicast_src_ip 192.168.118.5
    unicast_peer {
        # 其他机器ip
        192.168.118.3
    }

    # 设置nopreempt防止抢占资源
    nopreempt

    # 主备保持一致
    authentication {
        auth_type PASS
        auth_pass 1111
    }

    # 与上方nginx运行状况检测呼应
    track_script {
        chk_nginx
    }

    virtual_ipaddress {
        # 虚拟ip地址（VIP，一个尚未占用的内网ip即可）
        192.168.118.118
    }
}

主从机都需配置检测nginx是否在运行,不在允许就直接启动nginx的脚本,和keepalived放在一起

脚本名称 nginx_check.sh

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

只要配置好了,以后直接启动keepalived就好了,keepalived运行之后就会检测nginx是否在运行,不在运行就通过脚本去启动

自动重启不了解决方案

查看脚本是否有运行的权限
如果你是root登陆的话(不是的话，切换到root用户，对*.sh 赋可执行的权限)

chmod 777*.sh
或者
chmod +x *.sh

keepalived常用命令

#启动
service keepalived start
#停止
service keepalived stop
#查看状态
service keepalived status

开始测试

直接访问主机的nginx服务

 

 直接访问从机的nginx服务

 

 通过keepalived 设置的虚拟ip进行访问

 

 一切正常,将主机的keepalived服务给停掉,模拟服务器宕机的场景

然后再通过虚拟IP进行访问

 

 成功切换到备用服务器

接下来重启主服务器,再访问虚拟ip

 

 由此可见,当主机dowm掉的时候才会访问从机,当主机连进来的时候又回去访问主机

当主机正常运行通过ip addr命令的时候可以看到网络下多了个虚拟ip,而从机却没有,只要当主机挂了时候从机才会显示xuniip