Nginx uses reverse proxy to implement load balancing process analysis

Introduction

Based on docker container and docker-compose, you need to learn the basic use of docker in linux environment

Use two tomcat as load balancing servers

1. Use docker to pull tomcat and nginx images

Pull nginx reference

Pull tomcat reference

2. Use docker-compose to create two tomcat services

Create a new tomcat directory, create a docker-compose.yml file in the directory, and enter the following content:

version: '3'
services:
  tomcat1:
    image: tomcat
    container_name: tomcat1
    ports:
      - 9090:8080

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

Run the following command in the same directory as the docker-compose.yml file to start the container (-d means running in the background)

docker-compose up -d

After success, check the docker container list

Order

docker ps

The result example has two containers, tomcat1 and tomcat2

CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
271dd3610d1d tomcat "catalina.sh run" 58 minutes ago Up 58 minutes 0.0.0.0:9091->8080/tcp tomcat2
fa19d20f0022 tomcat "catalina.sh run" 58 minutes ago Up 58 minutes 0.0.0.0:9090->8080/tcp tomcat1

Enter the container interactively and modify the homepage content to distinguish between the two tomcats (tomcat is used as an example below)

Order

docker exec -it fa19d20f0022 bash

Add content to the homepage

echo "9090" >> webapps/ROOT/index.jsp

3. Create nginx service

Create a new nginx directory, create a docker-compose.yml file in the directory, and enter the following content:

version: '3.1'
services:
  nginx:
    restart: always
    image: nginx
    container_name: nginx
    ports:
      - 81:80
    volumes:
      - ./conf/nginx.conf:/etc/nginx/nginx.conf

Because docker-compose automatically treats /conf/nginx.conf as a folder, you need to create a conf directory in the nginx directory before creating the container, and create an nginx.conf file in the conf directory and enter the following content:

user nginx;
worker_processes 1;

events {
 worker_connections 1024;
}

http {
 upstream myapp1 {
  server [server ip]:9090 weight=10;
  server [server ip]:9091 weight=10;
 }
 server {

  listen 80;
  server_name [server ip];
  location / {
   proxy_pass http://myapp1;
  }
 }
}

Run in the same directory as docker-compose.yml

docker-compose up -d

4. Visit [server ip]:81, refresh several times, and observe the switching between the two tomcat services.

The above is the full content of this article. I hope it will be helpful for everyone’s study. I also hope that everyone will support 123WORDPRESS.COM.