How to Install and Utilize Docker Compose on CentOS 8

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Docker Compose is an invaluable tool that simplifies the management of complex applications by allowing you to define and orchestrate multiple containers with a single service. It utilizes a YAML file where you can specify the different services that make up your application, focusing on development, testing, and staging environments.

This guide will walk you through the process of installing and using Docker Compose on a CentOS 8 server.

Requirements

  • A server running CentOS 8.
  • A root password configured on the server.

Install Docker

First, ensure Docker is installed on your server. If Docker is not already installed, add the Docker-CE repository to your system with the command below:

dnf config-manager --add-repo=https://download.docker.com/linux/centos/docker-ce.repo

With the repository added, install the latest version of Docker using:

dnf install docker-ce --nobest -y
systemctl start docker
systemctl enable docker

Verify your Docker installation with:

docker --version

Expected output:

Docker version 19.03.5, build 633a0ea

Install Docker Compose

Docker Compose is not available in the default CentOS 8 repository, so you need to download it from the official GitHub repository.

First, install the curl command if it is not already installed:

dnf install curl -y

Use curl to download the latest Docker Compose version:

curl -L https://github.com/docker/compose/releases/download/1.25.0/docker-compose-`uname -s`-`uname -m` -o /usr/local/bin/docker-compose

After downloading, make it executable:

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

Verify the installation:

docker-compose --version

Expected output:

docker-compose version 1.25.0, build 0a186604

List all available Docker Compose options:

docker-compose --help

Docker Compose Commandline Options

Deploy Drupal with Docker Compose

Next, we will demonstrate how to deploy Drupal with Docker Compose.

Create a directory for your Drupal setup:

mkdir drupal

Create a docker-compose.yaml file inside this directory:

nano drupal/docker-compose.yaml

Insert the following configuration:

version: '3.3'
    
services:
  drupal:
    image: drupal:latest
    ports:
      - 80:80
    volumes:
      - drupal_modules:/var/www/html/modules
      - drupal_profiles:/var/www/html/profiles
      - drupal_themes:/var/www/html/themes
      - drupal_sites:/var/www/html/sites
    restart: always

  postgres:
    image: postgres:10
    environment:
      POSTGRES_PASSWORD: your_postgres_password
    volumes:
        - db_data:/var/lib/postgresql/data
    restart: always

volumes:
  drupal_modules:
  drupal_profiles:
  drupal_themes:
  drupal_sites:
  db_data:

Save and close the file when done. Navigate to the Drupal directory and launch the containers:

cd drupal
docker-compose up -d

Your Drupal and PostgreSQL containers will start downloading and running.

To check the running containers:

docker-compose ps

Expected output:

      Name                     Command               State         Ports       
-------------------------------------------------------------------------------
drupal_drupal_1     docker-php-entrypoint apac ...   Up      0.0.0.0:80->80/tcp
drupal_postgres_1   docker-entrypoint.sh postgres    Up      5432/tcp

Access the Drupal installation wizard via http://your-server-ip.

Choose language

Working with Docker Compose

Here are some common Docker Compose commands:

To stop the services:

docker-compose stop

Expected output:

Stopping drupal_drupal_1   ... done
Stopping drupal_postgres_1 ... done

To start the services:

docker-compose start

To view logs of all containers:

docker-compose logs

To view logs of a specific container:

docker-compose logs drupal

To inspect the configuration file:

docker-compose config

To pause and unpause services:

docker-compose pause

Output:

Pausing drupal_postgres_1 ... done
Pausing drupal_drupal_1   ... done

docker-compose unpause

Output:

Unpausing drupal_drupal_1   ... done
Unpausing drupal_postgres_1 ... done

To remove services:

docker-compose down

Expected output:

Stopping drupal_drupal_1   ... done
Stopping drupal_postgres_1 ... done
Removing drupal_drupal_1   ... done
Removing drupal_postgres_1 ... done
Removing network drupal_default

To remove volumes:

docker-compose down --volumes

Expected output:

Removing network drupal_default
WARNING: Network drupal_default not found.
Removing volume drupal_drupal_modules
Removing volume drupal_drupal_profiles
Removing volume drupal_drupal_themes
Removing volume drupal_drupal_sites
Removing volume drupal_db_data

Conclusion

This tutorial provided you with the steps to install and use Docker Compose on a CentOS 8 server. You should now have a fundamental understanding of how to manage Docker containers using Docker Compose.

FAQ

  • What is Docker Compose?
    Docker Compose is a tool for defining and running multi-container Docker applications.
  • Why use Docker Compose?
    Docker Compose simplifies the process of managing multiple containers by using a single YAML file and a single command to streamline deployment.
  • Can Docker Compose be used in production environments?
    While it’s primarily designed for development and testing, Docker Compose can be adapted for production, but Docker Swarm or Kubernetes are more commonly used for production deployments.
  • How do I update Docker Compose?
    You can update Docker Compose by downloading the latest binary from the official GitHub repository and replacing the existing one.
  • Is it necessary to use Docker Compose for single-container applications?
    No, for single-container applications, Docker by itself is sufficient. Docker Compose is mainly advantageous when managing applications consisting of multiple containers.