How to Install Docker Compose on Ubuntu 20.04

Docker compose is an useful tool for managing multiple docker containers. It helps us to launch, update and build a group of docker containers with single commands. In case of multi container application, docker compose helped us to manage it easier.

This tutorial helps you to install Docker compose on a Ubuntu 20.04 LTS Linux system.

Prerequisites

• A system running Ubuntu 20.04.
• Pre-installed Docker service on Ubuntu 20.04.
• Terminal access with sudo privileged account.

Install Docker Compose on Ubuntu

Docker compose binary is available on official Github release. Use curl command line tool to download docker compose binary and place under the PATH environment to make it available globally.

First, make sure you have latest curl binary installed on your system.

sudo apt update 
sudo apt install -y curl 

Now, confirm the latest docker-compsoe binary version on Github releases page. At the time of this writing this tutorial, the current stable version is 1.29.2.

The following command will download the docker-compose binary version 1.29.2 and save this file at /usr/local/bin/docker-compose.

sudo curl -L "https://github.com/docker/compose/releases/download/1.29.2/docker-compose-Linux-x86_64" -o /usr/local/bin/docker-compose 

Make the binary docker-compose file executable

chmod +x /usr/local/bin/docker-compose 

Verify the the docker-compose version by running the followign command.

docker-compose --version 

Output:

docker-compose version 1.29.2, build 5becea4c

Run a Docker Compose Example

At this stage Docker compose have been configured on your Ubuntu system.

1. First of all, create a directory, which will contain all the files related to this example.

   mkdir ~/myapp && cd ~/myapp
   

2. Now, create a html directory. We will map this directory as document root of web server running under the Docker container

   mkdir html
   

3. Now create a index.html file under html file.

   echo "<h2>Hello TecAdmin</h2>" > html/index.html 
   

4. Next, create the most important configuration file docker-compose.yml. This is the file contains all settings used by the docker-compose. Basis of this file docker-compose setup the images, network and containers etc.

   I will discuss this in parts for the better understanding. Edit file in a text editor:

   sudo nano docker-compose.yml 
   

   Add the following content to file.

   version: '3'
    
   services:
     web:
       image: "php:8.0-apache"
       restart: 'always'
       volumes:
         - ./html:/var/www/html
       ports:
         - '8080:80'
   

   The above content shows that we are using latest version of docker compose version 3.

   Next, we defined a service 「web」 under sevices section. This will launch a docker container using pre-build 「php:8.0-apache」 AMI. The 「html」 directory in current folder will be mounted to containers /var/www/html directory.

   Keep your file in editing mode.

5. Next add a MySQL database container in docker compose file.

   version: '3'
    
   services:
     web:
       image: "php:8.0-apache"
       restart: 'always'
       volumes:
         - ./html:/var/www/html
       ports:
         - '8080:80'
       depends_on:
         - mysql
       links:
         - mysql
     mysql:
       image: mysql:8
       container_name: mysql
       environment:
         MYSQL_ROOT_PASSWORD: my_secret_password
         MYSQL_DATABASE: app_db
         MYSQL_USER: db_user
         MYSQL_PASSWORD: db_user_pass
       ports:
         - "6033:3306"
       volumes:
         - dbdata:/var/lib/mysql
   volumes:
     dbdata:
   

   You can change the MySQL versions and access credentials. We have also updated web container configuration to link with database. This will allow web container to access database directly.

   Keep your file in editing mode…

6. Optional but helpful to add phpmyadmin docker container. This will will help you to access database and its users.

   After adding the phpmyadmin, your docker-compose.yml look like below:

   version: '3'
    
   services:
     web:
       image: "php:8.0-apache"
       restart: 'always'
       volumes:
         - ./html:/var/www/html
       ports:
         - '8080:80'
       depends_on:
         - mysql
       links:
         - mysql
   
     mysql:
       image: mysql:8
       container_name: mysql
       environment:
         MYSQL_ROOT_PASSWORD: my_secret_password
         MYSQL_DATABASE: mydb
         MYSQL_USER: dbuser
         MYSQL_PASSWORD: dbuser_password
       ports:
         - "6033:3306"
       volumes:
         - dbdata:/var/lib/mysql
   
     phpmyadmin:
       image: phpmyadmin/phpmyadmin
       container_name: phpmyadmin
       links:
         - mysql
       environment:
         PMA_HOST: mysql
         PMA_PORT: 3306
         PMA_ARBITRARY: 1
       restart: always
       ports:
         - 8081:80
   
   volumes:
     dbdata:
   

   Save you file and close it.

7. Next, run the following command to pull all the images on your system.

   sudo docker-composer pull 
   

8. Next run the build command to create docker images. For this example, you can skip this command as we are using pre build images only.

   sudo docker-composer build
   

9. finally, run the docker-compose up command. Use 「-d」 option to deamonize container to keep running.

   sudo docker-composer up -d 
   

10. The web server container is listening on port 8080, which we have bind with containers port 80. Access your host machine ip address on port 8080. You will see the index.html created under html directory.

    
    To make change just update html directory content and refresh page.

Conclusion

This tutorial helped you to install and use docker-compose on Ubuntu systems. The above instructions can be used on Ubuntu 16.04 LTS and above systems.