What is Docker Compose and how to install it

Docker Compose is a tool for defining and managing multi-container applications on the Docker platform. It allows you to merge multiple containers together and define all the necessary customizations, dependencies and relationships between them in a configuration file.

What does Docker Compose allow?

Using Docker Compose, you can define and run complex applications consisting of multiple services or components, each running in its own Docker container.

Docker Compose allows you to easily scale, manage and communicate between containers within the same environment. The main benefits of using it are:

• The ease of defining and managing complex applications consisting of multiple containers.
• the ability to define dependencies and relationships between containers to easily manage the order in which services are started and stopped
• automatic scaling and distribution of services within containers.
• easy work with environment variables and container settings.

Docker Compose uses a YAML file to define containers, their settings, environment variables, networks, and other parameters. This file can be easily understood and edited.

How to install Docker Compose

There are simple steps to install Docker Compose on Linux.

Docker Compose requires that you have Docker Engine on your system. If you already have Docker Engine installed, you can proceed to the next step. If you do not have Docker Engine, however, follow the commands:

Update the package index:

sudo apt update

Install the packages required to add new repositories via HTTPS:

sudo apt install apt-transport-https ca-certificates curl software-properties-common

Add an official Docker GPG key:

curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg

Install a stable Docker repository:

echo "deb [arch=amd64 signed-by=/usr/share/keyrings/docker-archive-keyring.gpg] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null

Update the package index again:

sudo apt update

Install the Docker Engine and its dependencies:

sudo apt install docker-ce docker-ce-cli containerd.io

Make sure the Docker service is running:

sudo systemctl start docker

Add the current user to the docker group to run Docker commands without using sudo:

sudo usermod -aG docker $USER

After that, restart the system or log out of the current session and log back in.

Installing Docker Compose

First, install the dependencies for Docker Compose:

sudo apt install libffi-dev libssl-dev
sudo apt install python3 python3-pip
sudo apt install -y python3-dev

sudo apt remove docker-compose
sudo pip3 uninstall docker-compose

Install Docker Compose using pip3:

sudo pip3 install docker-compose

Verify that Docker Compose is successfully installed:

docker-compose --version

You should see a message indicating the version of Docker Compose installed.

Docker Compose should now be successfully installed on your Linux system. You can use it to manage multi-container applications on Docker.