Installing Drupal with Docker Compose on Ubuntu 18.04

What Are Docker and Docker Compose?

Docker is a system that provides pre-configured, self-contained applications, frameworks, and software stacks, such as WordPress, Golang, or LAMP. Even entire Linux distributions can be run in Docker. When deployed, these software packages are referred to as containers. Docker also allows you to create your own containers that include any custom software you’d like.

Docker Compose is a complementary system which helps you link together individual Docker containers so they can work together. This guide walks through the deployment of a Drupal container and another PostgreSQL container that Drupal will use to store its data. Docker Compose will facilitate the networking between them.

Containers for Drupal and PostgreSQL are available from Docker Hub in the form of images. A Docker image is a static snapshot of a container which is used to create new container instances. Docker Hub is an official repository where individuals and organizations can upload Docker images for public consumption.

Why Use Docker to Run Drupal?

Using the Drupal and PostgreSQL images from Docker Hub offers the following benefits:

• The configuration of the software has been done for you, which means that you don’t need to follow a step-by-step process for each application to get them running on your system.
• Updating your software is as simple as downloading the latest images from Docker Hub.
• Images and containers are self-contained, which means that they are easy to clean up if you decide to remove them.

Before You Begin

1. Familiarize yourself with our Getting Started guide and complete the steps for setting your Linode’s hostname and timezone.

2. Follow our Securing Your Server guide to create a standard user account, harden SSH access, and create firewall rules for your web server; you may need to make additional firewall exceptions for your specific application.

   Note

   This guide is written for a non-root user. Commands that require elevated privileges are prefixed with sudo. If you’re not familiar with the sudo command, visit our Users and Groups guide.

   All configuration files should be edited with elevated privileges. Remember to include sudo before running your text editor.

Install Docker

To install Docker CE (Community Edition), follow the instructions within one of the guides below:

• Installing and Using Docker on Ubuntu and Debian

• Installing and Using Docker on CentOS and Fedora

For complete instructions on even more Linux distributions, reference the Install Docker Engine section of Docker’s official documentation.

Install Docker Compose

Docker Compose is available in plugin and standalone variants. However, Docker’s official documentation prioritizes the plugin. Further, the plugin has a straightforward installation and works well with past Docker Compose commands.

These steps thus show how to install the Docker Compose plugin. If you are interested in installing the standalone Docker Compose application, follow Docker’s official installation guide.

docker-compose [command]

docker compose [command]

1. Enable the Docker repository for your system’s package manager. The repository is typically already enabled after you have installed the Docker engine. Follow our relevant guide on installing Docker to enable the repository on your system.

2. Update your package manager, and install the Docker Compose plugin.

   • On Debian and Ubuntu systems, use the following commands:

   sudo apt update
   sudo apt install docker-compose-plugin
   • On CentOS, Fedora, and other RPM-based distributions, use the following commands:

   sudo yum update
   sudo yum install docker-compose-plugin

Set Up Drupal

1. Create a new directory in your home folder called my_drupal and cd into it:

   mkdir ~/my_drupal/
   cd ~/my_drupal/
   

2. Create a file named docker-compose.yml in this folder and add the following contents. Set your own password for the POSTGRES_PASSWORD option.

   File: docker-compose.yml

   1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

   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:

3. From the my_drupal directory, start your Docker containers:

   docker-compose up -d
   

4. The Docker containers will take a minute or two to start up Drupal and PostgreSQL. Afterwards, you can visit your Linode’s IP address in your web browser and you should be directed to the Drupal setup form.

5. On the Set up database page, select PostgreSQL as the Database type and enter the following values:

   • Database name: postgres

   • Database username: postgres

   • Database password: The password you set in the docker-compose.yml file

   • Host (under Advanced Options): postgres

6. Complete the other screens in the setup guide. When creating your Drupal user, be sure to enter a password that is different from your PostgreSQL password.

Usage and Maintenance

You do not need to manually start your containers if you reboot your Linode, because the option restart: always was assigned to your services in your docker-compose.yml file. This option tells Docker Compose to automatically start your services when the server boots.

Stop Drupal

To stop your Drupal application:

cd ~/my_drupal/
docker-compose stop

This will stop the running Drupal and PostgreSQL containers, but will not remove them.

Restart Drupal

To restart your Drupal application:

cd ~/my_drupal/
docker-compose start

Stop and Remove Drupal

To stop and remove containers, networks and images created by the docker-compose.yml file:

cd ~/my_drupal/
docker-compose down

When a Docker container is taken down, it is also deleted; this is how Docker is designed to work. However, your Drupal files and data will be preserved, as the docker-compose.yml file was configured to create persistent volumes for that data.

If you want to remove this data and start over with your Drupal site, you can add the --volumes flag to the previous command. This will permanently delete the Drupal customizations you’ve made so far.

docker-compose down --volumes

Update Drupal

The docker-compose.yml specifies the latest version of the Drupal image, so it’s easy to update your Drupal version:

docker-compose down
docker-compose pull && docker-compose up -d

Next Steps

More extensive documentation on Docker is available in the Containers section of the Linode Guides & Tutorials site.