Docker Compose

 Compose is a tool for defining and running multi-container Docker applications. With Compose, you use a YAML file to configure your application’s services. Then, with a single command, you create and start all the services from your configuration.

Using Compose is basically a three-step process:

1. Define your app’s environment with a Dockerfile so it can be reproduced anywhere.

2. Define the services that make up your app in docker-compose.yml so they can be run together in an isolated environment.

3. Run docker-compose up and Compose starts and runs your entire app.

Install Docker compose file

• DOCKER_CONFIG=${DOCKER_CONFIG:-$HOME/.docker}
• mkdir -p $DOCKER_CONFIG/cli-plugins
• curl -SL https://github.com/docker/compose/releases/download/v2.19.0/docker-compose-linux-x86_64 -o $DOCKER_CONFIG/cli-plugins/docker-compose
• chmod +x $DOCKER_CONFIG/cli-plugins/docker-compose
• docker compose version

Example

version: '3.3'

services:
   db:
     image: mysql:5.7
     volumes:
       - db_data:/var/lib/mysql
     restart: always
     environment:
       MYSQL_ROOT_PASSWORD: somewordpress
       MYSQL_DATABASE: wordpress
       MYSQL_USER: wordpress
       MYSQL_PASSWORD: wordpress

   wordpress:
     depends_on:
       - db
     image: wordpress:latest
     ports:
       - "8000:80"
     restart: always
     environment:
       WORDPRESS_DB_HOST: db:3306
       WORDPRESS_DB_USER: wordpress
       WORDPRESS_DB_PASSWORD: wordpress
       WORDPRESS_DB_NAME: wordpress
volumes:
    db_data: {}

docker-compose up -d

docker-compose down

Example -2

version: '3.3'

services:
   db:
     image: ramansharma95/mysql
   webapp:
     image: ramansharma95/webapp
     ports:
       - "84:80"

  Run the following command in mysql container (docker exec -it <<containerid>> bash)
     mysql -uroot -pwhizlabs

create database company;

use company;

create table employee ( name varchar(30), mobile varchar(30));

select * from employee;

Docker Compose Python Example

Docker Compose multi Docker file Example

Docker Compose with Custom Network

Docker Compose with Predefined network

Docker Compose Examples