How to install Docker on Debian [15 Easy Steps ]

Written by

Ojash

Reviewed by

Akshat

Last updated: July 20, 2023

Expert verified

Docker is an open-source platform that enables developers to package and distribute applications as self-contained containers. These containers encapsulate the application code, along with all its dependencies, into a single, portable unit. With Docker, you can easily deploy applications across different environments without worrying about compatibility issues or system dependencies. In this comprehensive guide, I will walk you through the process to install Docker on Debian, a highly popular and versatile Linux distribution. I will also discuss common errors that can occur when installing and using docker.

How to Install Docker on Debian

To install Docker on Debian, your system needs to meet the following requirements: Debian 9 (Stretch) or newer as the operating system, an x86-64 (64-bit) processor architecture, a Linux kernel version of 3.10 or newer, at least 2 GB of available memory (RAM), and sufficient disk space to accommodate Docker images and containers. To install Docker via the Docker repository, follow these steps:

1. Open a Terminal window from the application menu.

2. Run the following command to update the package lists:

<strong>$ sudo apt update</strong>

3. This command will update the package lists to ensure you have the latest available versions.

4. Once the package lists are updated, upgrade the installed packages to their latest versions:

<strong>$ sudo apt upgrade</strong>

5. During the upgrade process, you might be prompted to confirm package updates. Enter Y to proceed with the upgrades.

6. Install the necessary packages to allow apt to use a repository over HTTPS:

<strong>$ sudo apt install apt-transport-https ca-certificates curl software-properties-common</strong>

7. This command installs the required packages to securely communicate with repositories over HTTPS.

8. Add Docker’s official GPG key by running the command:

<strong>$ curl -fsSL https://download.docker.com/linux/debian/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg</strong>

9. This command adds Docker’s GPG key to ensure the integrity and authenticity of the downloaded packages.

10. To Add the Docker repository to Debian’s APT sources execute the command:

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

11. This command adds the Docker repository to your system’s APT sources, allowing you to install Docker.

12. Update the package lists to include the Docker repository:

<strong>$ sudo apt update</strong>

13. This command updates the package lists to include the Docker repository you added in the previous step.

14. Finally, install Docker using the following command:

<strong>$ sudo apt install docker-ce docker-ce-cli containerd.io</strong>

15. This command installs Docker and its dependencies on your Debian system.

Configuration of Docker on Debian

After successfully installing Docker on Debian, there are a few post-installation steps to ensure optimal usage and security. By managing Docker as a non-root user, configuring network settings and firewalls, and verifying the installation, you can create a secure and efficient environment for deploying and managing containerized applications.

1. Managing Docker as a Non-Root User

Running Docker as a non-root user is recommended to enhance security and prevent unauthorized access to sensitive system resources. To manage Docker as a non-root user, add your user to the docker group using the following command:

<strong><code>$ sudo usermod -aG docker $USER</code></strong>

Log out of your session and log back in to apply the group changes.

2. Checking Docker Version and System Status

Verifying the Docker version and system status is crucial to ensure the correct installation and functioning of Docker on Debian. 

1. To check the installed Docker version, open a Terminal and run the following command:

<strong>$ docker --version</strong>

2. The command will display the installed docker version.

3. Additionally, you can check the running status of Docker and obtain system information using the following command:

<strong>$ docker info</strong>

4. The output will be:

3. Running a Sample Docker Container

To validate the Docker installation and familiarize yourself with basic container management, you can run a sample Docker container. Follow these steps to run a simple Hello, World! container:

1. Open a Terminal and execute the following command:

<strong>$ docker run hello-world</strong>

2. Docker will pull the hello-world image from the Docker Hub registry and run it as a container.
3. If everything is set up correctly, you will see a message indicating that Docker is working correctly.

5 Common Errors When Installing and Using Docker on Debian

Docker is a powerful tool for containerization, but users may encounter errors during installation and usage. By being aware of these common errors and their solutions, you can troubleshoot Docker-related issues effectively, ensuring a smooth installation and usage experience on Debian. Here are five common errors that you may encounter:

• 🐳 “Cannot connect to the Docker daemon” error: This error indicates that the Docker daemon is not running or inaccessible. To resolve it, start the Docker daemon using the command sudo service docker start and ensure that you have the necessary permissions to access the Docker socket. You can add your user to the docker group using sudo usermod -aG docker $USER and then log out and log back in to apply the changes.
• 🚫 “Permission denied: docker.sock” error: This error suggests a permissions issue with the Docker socket. To fix it, add your user to the docker group using the command sudo usermod -aG docker $USER and then log out and log back in for the changes to take effect. This will grant your user the necessary permissions to access the Docker socket.
• 📦 “Unable to locate package docker-ce” error: This error indicates that the Docker package could not be found in the repositories. Make sure you have added the Docker repository correctly and run sudo apt update before attempting to install Docker. This ensures that the package lists are up to date and include the Docker repository.
• 🚩 “command not found” error: This error suggests that the Docker binary is not in your system’s PATH. Verify the Docker installation and ensure that the Docker binary is in the correct location (/usr/bin/docker). If not, you may need to add it manually to the PATH environment variable to make it accessible system-wide.
• 🔒 “Permission denied while connecting to Docker daemon socket” error: This error occurs when the user does not have the necessary permissions to access the Docker socket. Run Docker commands with sudo, or add your user to the docker group using sudo usermod -aG docker $USER and log out and back in to resolve the issue. This grants the required permissions to access the Docker daemon socket.

In Conclusion

I hope this guide has provided you with a step-by-step approach to successfully install Docker on Debian. Additionally, I have highlighted some common errors that may occur during the installation process. Being aware of these potential pitfalls will enable you to troubleshoot any issues that may arise and ensure a smooth Docker experience.

To continue expanding your knowledge and skills in Docker, consider exploring the following articles: Dockerizing Applications, Building Microservices with Docker, and Securing Docker Containers. Keep exploring, stay curious, and embrace the vast potential of Docker and its ever-growing ecosystem.

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