一、环境说明
系统:Centos 7.6
主机:四台,负载均衡两台:node1(192.168.145.27/24),node2(192.168.145.37/24);后端服务器两台:real1(192.168.145.47/24),real2(192.168.145.57/24)
VIP:192.168.145.100
软件:nginx-1.18.0.tar.gz,keepalived-1.3.5(光盘yum源安装)
二、实现过程
2.1、Nginx安装与配置
(1) Nginx的安装
两台主机都要安装,以node1为例。
[root@node1 ~]# wget https://nginx.org/download/nginx-1.18.0.tar.gz [root@node1 ~]# useradd -r -s /sbin/nologin nginx [root@node1 ~]# tar -xf nginx-1.18.0.tar.gz [root@node1 ~]# cd nginx-1.18.0/ [root@node1 nginx-1.18.0]# yum install -y gcc pcre-devel openssl-devel zlib-devel [root@node1 nginx-1.18.0]# ./configure --prefix=/usr/local/nginx > --user=nginx > --group=nginx > --with-http_ssl_module > --with-http_v2_module > --with-http_realip_module > --with-http_stub_status_module > --with-http_gzip_static_module > --with-pcre > --with-stream > --with-stream_ssl_module > --with-stream_realip_module [root@node1 nginx-1.18.0]# make && make install [root@node1 nginx-1.18.0]# ln -s /usr/local/nginx/sbin/nginx /usr/sbin/ [root@node1 nginx-1.18.0]# nginx
(2) 修改nginx配置文件,两台配置一样
[root@node1 ~]# grep -Ev "^$|#" /usr/local/nginx/conf/nginx.conf user nginx nginx; worker_processes 1; events { worker_connections 1024; } http { include mime.types; default_type application/octet-stream; log_format main '$remote_addr - $remote_user [$time_local] "$request" ' '$status $body_bytes_sent "$http_referer" ' '"$http_user_agent" "$http_x_forwarded_for"'; sendfile on; keepalive_timeout 65; upstream web { server 192.168.145.47:80 weight=1 fail_timeout=5s max_fails=3; server 192.168.145.57:80 weight=1 fail_timeout=5s max_fails=3; } server { listen 80; server_name www.aaa.com; charset utf-8; access_log logs/access_www.log main; location / { proxy_pass http://web; proxy_set_header Host $host; proxy_set_header X-Forwarded-For $remote_addr; } } }
(3) 修改内核参数,让nginx可以绑定在vip上
#不修改内核参数,nginx会报以下错误: [root@node1 ~]# nginx -t nginx: the configuration file /usr/local/nginx/conf/nginx.conf syntax is ok nginx: [emerg] bind() to 192.168.145.100:80 failed (99: Cannot assign requested address) nginx: configuration file /usr/local/nginx/conf/nginx.conf test failed [root@node1 ~]# cat >> /etc/sysctl.conf <<EOF > net.ipv4.ip_nonlocal_bind = 1 > net.ipv4.ip_forward = 1 > EOF [root@node1 ~]# sysctl -p net.ipv4.ip_nonlocal_bind = 1 net.ipv4.ip_forward = 1 [root@node1 ~]# nginx -t nginx: the configuration file /usr/local/nginx/conf/nginx.conf syntax is ok nginx: configuration file /usr/local/nginx/conf/nginx.conf test is successful [root@node1 ~]# nginx -s reload
(4) 修改两台主机的/etc/hosts文件,使其能够解析www.aaa.com域名
[root@node1 ~]# vim /etc/hosts #添加以下内容 192.168.145.100 www.aaa.com
(5) 后端服务器配置访问页面
[root@real1 ~]# yum install -y httpd [root@real1 ~]# echo "192.168.145.47" > /var/www/html/index.html [root@real1 ~]# systemctl start httpd [root@real2 ~]# yum install -y httpd [root@real2 ~]# echo "192.168.145.57" > /var/www/html/index.htm [root@real2 ~]# systemctl start httpd
2.2、Keepalived的安装与配置
(1) Keepalived的安装
两台主机都要安装,使用yum源的安装方式。
[root@node1 ~]# yum install -y keepalived [root@node2 ~]# yum install -y keepalived
(2) 修改keepalived的配置文件
[root@node1 ~]# vim /etc/keepalived/keepalived.conf global_defs { notification_email { root@localhost } notification_email_from root@localhost smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id node1 vrrp_skip_check_adv_addr vrrp_strict vrrp_iptables vrrp_garp_interval 0 vrrp_gna_interval 0 } vrrp_script check_nginx { script "/etc/keepalived/check_nginx.sh" } vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 priority 100 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.145.100/24 dev eth0 label eth0:1 } track_script { check_nginx } }
[root@node2 ~]# vim /etc/keepalived/keepalived.conf global_defs { notification_email { root@localhost } notification_email_from root@localhost smtp_server 127.0.0.1 smtp_connect_timeout 30 router_id node2 vrrp_skip_check_adv_addr vrrp_strict vrrp_iptables vrrp_garp_interval 0 vrrp_gna_interval 0 } vrrp_script check_nginx { script "/etc/keepalived/check_nginx.sh" } vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 51 priority 80 advert_int 1 authentication { auth_type PASS auth_pass 1111 } virtual_ipaddress { 192.168.145.100/24 dev eth0 label eth0:1 } track_script { check_nginx } }
(3) 编写监测nginx的脚本
[root@node1 ~]# vim /etc/keepalived/check_nginx.sh #!/bin/bash if [ `ps -C nginx --no-header|wc -l` -eq 0 ];then /usr/local/nginx/sbin/nginx #尝试重新启动nginx sleep 2 if [ `ps -C nginx --no-header|wc -l` -eq 0 ];then /usr/bin/systemctl stop keepalived #启动失败,将keepalived服务关闭,让vip漂移到其它节点 #killall keepalived fi fi [root@node1 ~]# chmod +x /etc/keepalived/check_nginx.sh [root@node1 ~]# scp /etc/keepalived/check_nginx.sh 192.168.145.37:/etc/keepalived/check_nginx.sh