What is reverse proxy

The reverse proxy server is set up on the server side, which relieves the workload of the server by buffering frequently requested pages, forwards client requests to the target server on the internal network, and returns the results obtained from the server to the client requesting connection on the Internet, when the proxy server and the target host are connected. Together, it is represented as a server.

Many large Web sites now use reverse proxies. In addition to preventing malicious attacks on Intranet servers by external networks and reducing server pressure and access security control by caching, load balancing can also be carried out to distribute user requests to multiple servers.
 
 

Using Nginx reverse proxy

demand

• Two Tomcat services are proxied by Nginx reverse
• Nginx server: 192.168.230.130 reverse proxy Tomcat server: 192.168.230.130:90
• Nginx server: 192.168.230.130:8080 reverse proxy Tomcat server: 192.168.230.130:9090

Tomcat container cluster

Start two Tomcat containers, mapping ports 90 and 9090, respectively

Create docker-compose.yml

version: '3'
services:
  tomcat1:
    image: tomcat
    container_name: tomcat90
    ports:
      - 90:8080

  tomcat2:
    image: tomcat
    container_name: tomcat9090
    ports:
      - 9091:8080

Start container

docker-compose up -d

Configuring Nginx reverse proxy

• Modify the nginx.conf configuration file in the / usr/local/docker/nginx/conf directory

  	user  nginx;
  	# Specify the number of CPU resources to be used
  	worker_processes  1;
  	
  	events {
  	    # Connection Number
  	    worker_connections  1024;
  	}
  	
  	http {
  	    include       mime.types;
  	    default_type  application/octet-stream;
  	    sendfile        on;
  	    keepalive_timeout  65;
  	    
  		# Virtual Host Configuration
  	    server {
  	        # Designated Port
  	        listen       80;
  	        # Specify IP (can be domain name)
  	        server_name  192.168.230.130;
  	        location / {
  	            # Configuration Agent
  	            proxy_pass http://192.168.230.130:90
  	            # home page
  	            index  index.html index.htm index.jsp;
  	        }
  	    }
  	
  	    # Virtual Host II Configuration
  	    server {
  	        listen       8080;
  	        server_name  192.168.230.130;
  	        location / {
  	            proxy_pass http://192.168.230.130:9090
  	            index  index.html index.htm index.jsp;
  	        }
  	    }
  	}
  

• Start the Nginx container

  docker-compose up -d
  

• Open browser to access separately 192.168.230.130 and 192.168.230.130:8080

Nginx load balancing

Configure Nginx load balancing

• Modify the nginx.conf configuration file in the / usr/local/docker/nginx/conf directory

  user  nginx;
  # Specify the number of CPU resources to be used
  worker_processes  1;
  
  events {
      # Connection Number
      worker_connections  1024;
  }
  
  http {
      include       mime.types;
      default_type  application/octet-stream;
      sendfile        on;
      keepalive_timeout  65;
      # Define IP and device status for load balancing devices (Tomcat cluster) 
  	upstream tomcats {
  	      server 192.168.230.130:90 weight=10;
  	      server 192.168.230.130:9090 weight=10;
      }
      # Virtual Host Configuration
      server {
          # Designated Port
          listen       80;
          # Specify IP (can be domain name)
          server_name  192.168.230.130;
          location / {
              # Configuration Agent
              proxy_pass http://tomcats
              # home page
              index  index.html index.htm index.jsp;
          }
      }
      # Virtual Host II Configuration
      server {
          listen       8080;
          server_name  192.168.230.130;
          location / {
              proxy_pass http://tomcats
              index  index.html index.htm index.jsp;
          }
      }
  }
  

  Relevant configuration instructions
  • upstream: the state of each device:
  • down: Represents that the current server is temporarily not participating in the load
  • Weight: The default is 1. The larger the weight, the heavier the load.
  • max_fails: The number of requests allowed to fail defaults to 1, returning an error defined by the proxy_next_upstream module when the maximum number of requests exceeds
  • Fail_timeout: The pause time after the failure of access to max_fails.
  • Backup: When all other non-backup machines are down or busy, request the backup machine. So this machine will have the lightest pressure.
• Start container

  docker-compose up -d
  

• Open browser to access separately 192.168.230.130 and 192.168.230.130:8080