nginx-reverse proxy and load balancing

One, reverse proxy

1 Environmental description

nginx uses YUM method to install, version is 1.18

2 configuration steps

2.1 Operations on the back-end web server h2

Start Nginx service

systemctl start nginx  && systemctl enable nginx

Modify web server page content

First, we configure h2 to serve as a web server to provide a display of page content

Check and confirm the page root directory of Nginx

[root@h2 ~]# grep -C 3 'location /' /etc/nginx/conf.d/default.conf
    #charset koi8-r;
    #access_log  /var/log/nginx/host.access.log  main;

    location / {
    
    
        root   /usr/share/nginx/html;   # 页面目录
        index  index.html index.htm;    # 页面文件名称
    }

Modify the /usr/share/nginx/html/index.htmlcontents of the file are as follows:

真实 web 服务器  h2

Test whether you can access the web service

First execute the following command on h2 to visit the website

[root@h2 ~]# curl  h2
真实 web 服务器 h2

Then visit the website on h1

[root@h1 ~]# curl h2
真实 web 服务器 h2
[root@h1 ~]#

2.2 Operation on the reverse proxy server h1

Start Nginx service

systemctl start nginx  && systemctl enable nginx

Configure proxy

The /etc/nginx/conf.d/default.confcontents of the file to be modified following

[root@h1 ~]# egrep -v '^[ \t]*#|^$' /etc/nginx/conf.d/default.conf
server {
    
    
    listen       80;
    server_name  localhost;
    location / {
    
    
        # 这里就是配置代理的地方，使用关键字 proxy_pass
        # 后面跟的是真实服务器IP或者主机名加端口号，这里是 h2
        proxy_pass http://h2:80;  
    }
    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
    
    
        root   /usr/share/nginx/html;
    }
}

Reload the Nginx configuration file

[root@h1 ~]# nginx -s reload

test

Access the proxy server h1 on the client machine h3

[root@h3 ~]# curl h1
真实 web 服务器 h2
[root@h3 ~]#

Two, load balancing

1 Environmental description

Operate on the physical host

Add 2 hosts to the docer-compose.yml file

  h4:
    image: centos7-sshd
    container_name: h4
    hostname: h4.sharkyun.com
    privileged: true
    command: /usr/sbin/init
    networks:
      xiuyun_net:
        ipv4_address: 192.16.2.40

  h5:
    image: centos7-sshd
    container_name: h5
    hostname: h5.sharkyun.com
    privileged: true
    command: /usr/sbin/init
    networks:
      xiuyun_net:
        ipv4_address: 192.16.2.50

Start them

[xiguatian@development project]$ docker-compose up -d h4 h5

2 configuration steps

2.1 Deploy Nginx on h4 and h5 servers and set to enable self-start

Create a /etc/yum.repos.d/nginx.repofile and write the following:

[nginx-stable]
name=nginx stable repo
baseurl=http://nginx.org/packages/centos/$releasever/$basearch/
gpgcheck=1
enabled=1
gpgkey=https://nginx.org/keys/nginx_signing.key
module_hotfixes=true

Then execute the following command to install Nginx

yum -y  install nginx

Finally, execute the following command to start the Nginx server and set it to self-start after booting

systemctl start nginx && systemctl enable nginx

2.2 Configure the page content of the web server h4 and h5

Modify the default page content of h4

Modify the /usr/share/nginx/html/index.htmlcontents of the file are as follows:

[root@h4 ~]# echo "真实 web 服务器  h4" > /usr/share/nginx/html/index.html

Modify the default page content of h5

Modify the /usr/share/nginx/html/index.htmlcontents of the file are as follows:

[root@h5 ~]# echo "真实 web 服务器  h5" > /usr/share/nginx/html/index.html

Test whether the web service can be accessed in the proxy server line

First, execute the following commands on h1 to visit the websites of h4 and h5

[root@h1 ~]# curl h4
真实 web 服务器  h4
[root@h1 ~]# curl h5
真实 web 服务器  h5
[root@h1 ~]#

2.3 Configure the proxy server h1

Operate on the proxy server h1

Modify the Nginx configuration file of h1 /etc/nginx/conf.d/default.conf

upstream testapp {
    
    
    server h2:80;
    server h4:80;
    server h5:80;
}

server {
    
    
    listen       80;
    server_name  localhost;

    location / {
    
    
        proxy_pass http://testapp;
    }

    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
    
    
        root   /usr/share/nginx/html;
    }
}

Reload Nginx configuration file

[root@h1 ~]# nginx -s reload

2.4 Test whether the proxy server is valid

Operate on client h3

Visit h1 4 times consecutively on h3

[root@h3 ~]# curl h1
真实 web 服务器 h2
[root@h3 ~]# curl h1
真实 web 服务器  h4
[root@h3 ~]# curl h1
真实 web 服务器  h5
[root@h3 ~]# curl h1
真实 web 服务器 h2