环境准备：
实验目的：nginx 通过keepalived实现高可用
10.0.0.11 nginx1,keepalievd #nginx负载均衡配置主
10.0.0.12 nginx2,keepalievd #nginx负载均衡配置备
10.0.0.13 httpd1 #用来测试是否能够负载均衡
10.0.0.14 httpd2 #用来测试是否能够负载均衡
10.0.0.100 nginx的vip
一、nginx安装(10.0.0.11)
1.首先安装依赖
yum install pcre-devel* pcre* gcc* openssl* zlib* -y2.下载nginx
wget http://nginx.org/download/nginx-1.14.2.tar.gz我这里下载的是nginx1.14.2版本，如需下载其他版本可登录http://nginx.org/download选择
3.解压
tar -zxf nginx-1.14.2.tar.gz4.编译安装
cd nginx-1.14.2
./configure --prefix=/nginx --with-http_stub_status_module --with-http_ssl_module --with-http_realip_module
make && make install编译nginx可加的一些参数
--prefix=path 定义服务器保存文件的目录，默认为/usr/local/nginx
--sbin-path=path nginx执行文件名，默认为prefix/sbin/nginx
--conf-path=path 设置nginx.conf配置文件名，默认为prefix/conf/nginx.conf
--pid-path=path 设置nginx.pid文件名，它用来保存nginx主进程的进程ID，默认为prefix/logs/nginx.pid
--error-log-path=path 设置错误日志文件名，默认为prefix/logs/error.log
--http-log-path=path 设置HTTP请求日志文件名，默认为prefix/logs/access.log
--user-name=path 设置未授权用户名，默认为nobody
--group=name 设置组名，默认为未授权用户名
--with-select_module 编译或取消编译利用select()方法的模块
--with-poll_module 编译或取消编译利用poll()方法的模块
--without-http_gzip_module 取消编译HTTP服务器压缩响应的模块，需要zlip库
--without-http_rewrite_module 取消编译HTTP服务器重定向请求或修改请求URI地址的模块，需要PCRE库
--without-http_proxy_module 取消编译HTTP服务器代理模块
--with-http_ssl_module 编译添加对HTTPS协议的支持，需要OpenSSL库
--with-pcre=path 设置PCRE库的源代码路径，下载PCRE源码后解压缩到指定的path即可，剩下的交给nginx的./configure和make命令完成
--with-pcre-jit 编译PCRE库支持及时编译
--with-zlib=path 设置zlib库源代码的路径，同样下载zlib源码后解压到指定的path即可
--with-cc-opt=parameters 设置CFLAGS变量的额外参数
--with-ld-opt=parameters 设置链接时的额外参数
5.将、nginx/nginx为nginx用户授权（也可直接用root执行）
chown -R nginx:nginx /nginx/nginx6.切换到nginx用户进行配置
su - nginx7.修改/nginx/nginx/conf/nginx.conf文件
user nginx;
worker_processes 4;
events {
use epoll;
worker_connections 204800;
}
http {
include mime.types;
default_type application/octet-stream;
#access_log logs/access.log main;
sendfile on;
#tcp_nopush on;
#keepalive_timeout 0;
keepalive_timeout 65;
#gzip on;
server {
listen 80;
server_name localhost;
#charset koi8-r;
#access_log logs/host.access.log main;
location / {
sendfile on;
events {
use_epoll;
worker_connections 204800;
}
http {
include mime.types;
default_type application/octet-stream;
#access_log logs/access.log main;
sendfile on;
#tcp_nopush on;
#keepalive_timeout 0;
keepalive_timeout 65;
#gzip on;
include upstream.conf; #此处是将server区域和upstream区域单独写了一个配置文件，也可直接写道nginx.conf里
include servers.conf;
}8.编辑一个servers.conf文件(也可写在nginx.conf文件里)
touch servers.conf
vim servers.conf # 此处为http配置
#esblocation
server {
listen 20000; #此处是nginx服务对外暴露的端口，默认是80，普通用户不可使用1024一下的端口
#charset koi8-r;
#access_log logs/host.access.log main;
location / {
proxy_pass http://esbupstream; #负载均衡的实例名(可以随便起，但需要和upstrean区域或文件一致)
proxy_redirect off;
proxy_http_version 1.1;
proxy_set_header Host $host;
proxy_set_header X-Forwarded-For $remote_addr;
proxy_set_header connect "";
client_max_body_size 30m;
client_body_buffer_size 1024k;
proxy_connect_timeout 30;
proxy_send_timeout 120;
proxy_read_timeout 120;
proxy_buffer_size 128k;
proxy_buffers 8 128k;
proxy_busy_buffers_size 128k;
}
#error_page 404 /404.html;
#rewrite ^(.*)$ https://$host$1 permanent;
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
}9.编辑upstream.conf文件(也可写在nginx.conf文件里)
touch upstream.conf
vim upstream.conf
upstream esbupstream{
server 10.0.0.13:8080; #此处使用8080测试
server 10.0.0.14:8080; #此处使用8080测试
keepalive 16;
}
#访问主机nginx的20000端口会负载到10.0.0.11/12的8080端口
#此处为轮询，也可设置为加权轮询：
# server 10.0.0.13:8080 wight 1；
# server 10.0.0.14:8080 wight 2；10.检测nginx配置文件是否有错误
/nginx/nginx/sbin/nginx -t
nginx: the configuration file /nginx/nginx/conf/nginx.conf syntax is ok
nginx: configuration file /nginx/nginx/conf/nginx.conf test is successful启动nginx
/nginx/nginx/sbin/nginx11.为实现高可用在另外一台主机安装nginx(10.0.0.12)，安装方式和配置文件内容同上
二、安装配置keepalived(nginx主)
1.下载安装
#下载地址：http://www.keepalived.org/download.html
#centos7使用keepalived-1.2.19会有问题，建议使用高版本，此处使用keepalived-2.0.11
首先安装一些依赖：
yum install -y gcc openssl-devel popt-devel
yum install libnl* libpopt* popt-static* -y解压安装
tar -zxf keepalived-2.0.11.tar.gz
cd keepalived-2.0.11
./configure --prefix=/var/local/keepalived --sysconf=/etc
make && make install
cp /var/local/keepalived/sbin/keepalived /usr/sbin/2.编辑配置文件
vim /etc/keepalived/keepalived.conf
! Configuration File for keepalived
global_defs {
router_id nginx_master
}
#探测检测nginx的脚本
vrrp_script check_nginx {
script "/etc/keepalived/check_nginx.sh"
interval 2
weight 2
}
vrrp_instance VI_1 {
state MASTER
interface ens33
virtual_router_id 51
priority 100
advert_int 1
authentication {
auth_type PASS
auth_pass telling
}
track_script {
check_nginx
}
virtual_ipaddress {
10.0.0.100/24
}
}在/etc/keepalived/下新建check_nginx.sh文件
touch /etc/keepalived/check_nginx.sh
vim /etc/keepalived/check_nginx.sh
[root@esb2 keepalived]# cat check_nginx.sh
#!/bin/bash
if [ "$(ps -ef | grep "nginx: master process"| grep -v grep )" == "" ]
then
/etc/init.d/keepalived stop
fi#给脚本赋权
chomd a+x /etc/keepalived/check_nginx.sh
3.另一台nginx的keepalievd配置方法相同
配置文件以下字段有所区别：
state MASTER 主为MASTER ，备为SLAVE #实际测试主备与这个无关，与priority有关
priority 100 主设置为100，备设置为80 # 只要比主低就可以
4.启动keepalived
启动keepalive
systemctl start keepalived启动后查看状态：
[root@localhost keepalived]# ip a | grep ens33
2: ens33: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
inet 10.0.0.11/24 brd 10.0.0.255 scope global noprefixroute ens33
inet 10.0.0.100/24 scope global secondary ens33#配置成功！
三、测试访问VIP的20000端口，是否会负载到10.0.0.13/14的8080端口
测试负载轮询
[root@localhost keepalived]# curl 10.0.0.100:20000
This 10.0.0.13:8080
[root@localhost keepalived]# curl 10.0.0.100:20000
This 10.0.0.14:8080
[root@localhost keepalived]# curl 10.0.0.100:20000
This 10.0.0.13:8080
[root@localhost keepalived]# curl 10.0.0.100:20000
This 10.0.0.14:8080测试加权轮询：
[root@localhost keepalived]# curl 10.0.0.100:20000
This 10.0.0.13:8080
[root@localhost keepalived]# curl 10.0.0.100:20000
This 10.0.0.14:8080
[root@localhost keepalived]# curl 10.0.0.100:20000
This 10.0.0.14:8080
[root@localhost keepalived]# curl 10.0.0.100:20000
This 10.0.0.14:8080
[root@localhost keepalived]# curl 10.0.0.100:20000
This 10.0.0.13:8080
