Install Docker Compose on Ubuntu 20.04 and 22.04

Introduction

Docker Compose allows users to launch, execute, and manage multiple containers with a single command. It helps users define and run multi-container Docker applications and document and configure service dependencies (caches, databases, web service APIs, etc.).

This tutorial shows how to install Docker Compose on Ubuntu 20.04/22.04, introduces frequently used commands, and provides a container deployment example.

Prerequisites

• A system running Ubuntu 20.04/22.04.
• A user account with administrative privileges.
• Docker installed.
• A command line/terminal window access (Ctrl-Alt-T)

Install Docker Compose on Ubuntu

The easiest way to deploy Docker Compose on Ubuntu is by installing Docker Desktop, an application that provides a GUI. Additionally, Docker Desktop includes Docker Engine, Docker CLI, and Docker Compose.

However, Docker Desktop may not be practical for developers with Docker already deployed on Linux, as the application creates a custom Docker context and a parallel Docker installation. The recommended way to install Docker Compose for Linux Docker engine users is via the official Docker repository.

Follow the steps below to install Docker Compose using the Docker repository on Ubuntu.

Step 1: Install Required Packages

Use the following commands to install the packages necessary for adding third-party repositories to an Ubuntu system:

1. Refresh the list of packages:

sudo apt update

2. Install ca-certificates, a certificate authority package for verifying third-party identities, and curl, a data transfer tool:

sudo apt install ca-certificates curl

Step 2: Add Docker Repository

To use the Docker repository, add Docker's official GPG key and add the repository to the APT sources. Follow the steps below to complete this procedure:

1. Set ownership permissions for the /etc/apt/keyrings directory:

sudo install -m 0755 -d /etc/apt/keyrings

2. Download the key with curl:

sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc

3. Set read permissions for the key:

sudo chmod a+r /etc/apt/keyrings/docker.asc

4. Add the Docker repository to the list of APT sources:

echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \
  $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | \
  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

Step 3: Install Docker Compose Plugin

Once the Docker repository is registered on the system, install the Docker Compose plugin via APT by following the steps below:

1. Update the repository list:

sudo apt update

The Docker repository appears in the output.

2. Install Docker Compose:

sudo apt install docker-compose-plugin -y

3. After the download completes, confirm that Docker Compose is installed by typing:

docker compose version

The output shows the Docker Compose version number.

Test Run Docker Compose

Run a sample container with Docker Compose to test the installation. The following section provides an example of this procedure using the hello-world Docker container.

1. Create and go to the hello-world directory:

mkdir hello-world && cd hello-world

2. Create a compose.yml file to store container deployment instructions:

nano compose.yml

3. Paste the following code into the file. The code defines a service container named hello-world, which uses the hello-world:latest Docker image as the template.

version: '2'
services:
   hello-world:
      image:
         hello-world:latest

4. Save the file and exit.

5. Run Docker Compose by running the following command:

docker compose up

Docker Compose reads compose.yml and then creates and runs a container based on the instructions. The output shows the sample app that runs from the hello-world container.

Docker Compose Basic Commands

The docker compose command has the following syntax:

docker compose [subcommand] [arguments]

It features multiple subcommands, allowing for simple creation and management of container deployments. Some of the most frequently used commands include:

• up. Create and start containers based on the compose.yml file in the current directory.
• down. Stop and remove containers.
• start. Start existing service containers.
• pause. Pause running service containers.
• unpause. Unpause running service containers.
• stop. Stop service containers.
• kill. Force stop service containers.
• restart. Restart service containers.
• run. Run a command inside a service container.
• cp. Copy files/directories between the local filesystem and a service container.

Uninstall Docker Compose on Ubuntu

The procedure for removing Docker Compose is the same as for any other application installed via APT. Uninstall Docker Compose by typing:

sudo apt remove docker-compose-plugin

Confirm that you want to remove the application by entering Y when prompted.

Conclusion

After reading this article, you should know how to set up Docker Compose on Ubuntu 20.04/22.04. The article provided installation instructions alongside a list of frequently used Docker Compose commands and an example deployment.

Once you get into the practice of launching containers with pre-made Docker images, you may decide to start creating your own. If you are preparing to do so, read How to Create Docker Image With Dockerfile.