What is Docker?
Docker is a platform for creating, running, and managing applications in containers. Containers are lightweight, portable units that isolate an application along with its dependencies, allowing it to run in different environments without compatibility issues. Thanks to Docker, applications are easy to move, scale, and manage. Docker is widely used in both production and testing environments, and its popularity is already significant.
Requirements
To install Docker, you need a Raspberry Pi with a running and configured operating system. If you are just starting and want to learn how to prepare your Raspberry Pi for operation, check out our guide How to set up Raspberry Pi step by step
Installing Docker on Raspberry Pi
Docker works perfectly on Raspberry Pi, offering reliability, lightness, and flexibility. To install Docker on your Raspberry Pi, follow the steps below for a quick deployment of this platform on your device.
1. System Update
Before installing Docker, it is worth ensuring that the system is up to date. To do this, run the following command to fetch the latest package information and install available updates:
sudo apt-get update && sudo apt-get upgrade -y
2. Removing Potential Conflicting Packages
If you previously installed Docker or other container management tools, it is advisable to remove them to avoid conflicts. The following loop will remove unnecessary packages:
for pkg in docker.io docker-doc docker-compose podman-docker containerd runc; do sudo apt-get remove $pkg; done
3. Installing Required Packages
Before installing Docker, make sure that the system has the necessary tools, such as TLS certificates and the curl tool for downloading files from the internet. Install them with the following command:
sudo apt-get install ca-certificates curl -y
4. Downloading and Adding Docker's GPG Key
To ensure that the installed packages come from a trusted source, add Docker's official GPG key. Execute the following commands:
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/debian/gpg -o /etc/apt/keyrings/docker.asc
sudo chmod a+r /etc/apt/keyrings/docker.asc
5. Adding the Docker Repository
Now you need to add Docker's official repository to the system. This allows the system to download and update Docker directly from its source.
echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/debian $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
6. Updating the Package List and Installing Docker
After adding the repository, update the package list again so the system can find Docker and its components.
sudo apt-get update
7. Installing Docker
After updating the package list, proceed with the actual installation of Docker:
sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin -y
8. User Configuration
By default, administrative privileges (sudo) are required to run Docker. If you want to use Docker as a regular user, add your username to the Docker group and refresh the user session. However, note that this approach is not recommended in production environments as it can lead to security issues. Allowing a user to run Docker without sudo grants access to system resources, which, if misused, can expose the system to attacks. Therefore, for security reasons, administrative privileges should always be used in production. Treat this setup mainly as a solution for testing and development.
sudo groupadd docker
sudo usermod -aG docker $USER
newgrp docker
9. Verifying the Installation
To check if the installation was successful, run the following command, which should return Docker’s version number:
docker --version
If you see the version number, it means that Docker has been successfully installed on your Raspberry Pi. Now you can start creating and managing containers! If you want to confirm that Docker is working properly, run the following command.
sudo docker run hello-world
Summary
Docker is a powerful tool that makes managing applications in containers quick and convenient. It allows you to run various services on your Raspberry Pi easily, saving resources and avoiding compatibility issues. If you are interested in other exciting projects using Raspberry Pi, check out our other posts – you will find plenty of inspiration and tips!