Unveiling the Ultimate Guide to Mastering Docker Installation in Linux - Don’t Miss Out!
Docker has become an essential tool for developers and system administrators due to its ability to simplify application deployment and management. In Linux, Docker offers many benefits, including portability, scalability, and resource isolation. If you’re new to the Docker world or want to learn more about installing Docker on Linux, this guide offers the ultimate guide to mastering Docker installation in Linux.
Step 1: Update your system
Before you install Docker, it’s essential to ensure that your system is up-to-date. To do this, run the commands below:
sudo apt update
sudo apt upgrade
This will update your system’s package list and install any available upgrades.
Step 2: Install Docker
There are different ways to install Docker on Linux, including using the official Docker installer script, using the package manager, or building from source. In this guide, we will show you how to install Docker using the package manager.
The steps below show you how to install Docker on Ubuntu Linux distribution:
sudo apt install docker.io
When the installation is complete, you can verify that Docker is installed correctly by checking its version:
sudo docker --version
You should see output similar to this:
Docker version 20.10.7, build f0df350
Step 3: Run Docker as a non-root user
By default, Docker requires root privileges to work correctly. However, running Docker as a root user poses a security risk. Therefore, it’s recommended to run Docker as a non-root user.
To do this, add your user to the Docker group:
sudo usermod -aG docker $USER
You will need to log out and log back in for the changes to take effect.
Step 4: Test Docker installation
Now it’s time to test Docker installation to ensure that it’s working correctly. The easiest way to do this is to run the “hello-world” container, which is available on Docker Hub:
sudo docker run hello-world
This will download a Docker image and run a container that prints out a message that confirms that Docker installation is working correctly.
Conclusion
Congratulations! You have successfully installed Docker on your Linux system. Docker offers many possibilities for developers and system administrators, including the ability to create isolated environments for testing, to deploy applications to production, and to simplify the deployment process significantly. With this guide, you can now master the installation process of Docker in Linux and start exploring its many features.
Virtualization and containers are continually rising in popularity. The reasons why they’re useful mostly revolve around the isolation, security and portability benefits they provide.
For example, if you’re offering some form of cloud services, they make it easier to keep customer data and services isolated from each other. But it’s not limited to these scenarios. If you are a developer of a Linux application, you will quickly realize how hard it is to make your app available to all Linux distributions.
Once you make your program work in Ubuntu, making it also function in Arch Linux, Debian and other distros won’t be as straightforward as you might think. Every distribution is different, and you have to make adaptations so that your utility functions in every one of them.
Containerization makes it easier to “develop once, deploy everywhere.” That’s because instead of relying on the operating system to provide what your application needs, all dependencies are bundled in the container itself. Once the container works, you can move it around from computer to computer and between different operating systems easily.
Docker is a containerization utility that became very popular for simplifying such tasks. Furthermore, when something goes wrong with the operating system, instead of having to reinstall and reconfigure the application, you just reinstall the operating system, copy the container back and continue where you left off.
Cleanup Old Docker Installations
This is an optional step, required only if you have older Docker versions already installed. These might conflict with newer versions, especially if they come from different repositories than what you’ll use here.
On Debian or Ubuntu, clean up with:
On Fedora:
How to Install Docker on Ubuntu
Open a terminal emulator and install prerequisites.
Check Docker’s GPG key fingerprint.
At the time of writing this tutorial, the fingerprint was 9DC858229FC7DD38854AE2D88D81803C0EBFCD88. This may change in the future. Check Docker’s official website to see if they match. The key is used to verify digital signatures, so you can make sure the software you are installing is legitimate and not malware uploaded to the server by an attacker.
Once you make sure you have the right key, add it to APT’s trusted keys.
Add Docker’s repository for Ubuntu to your software sources.
Install Docker.
If you also need Docker Compose, you can install it with:
If you don’t know what this is, you probably don’t need it.
Most docker commands need to be prefixed with sudo. If you want to avoid having to type your password every time, add your user to the docker group.
Log out of your graphical user interface and log back in. Now you can use commands such as docker ps instead of sudo docker ps.
How to Install Docker on Debian
Since Ubuntu is created from Debian, the steps are very similar.
Check fingerprint which should be the same as in the previous section.
Add to trusted keys.
Add software sources.
If you also need Docker Compose, install it with:
To use Docker commands without prefixing with sudo:
Then log out and log back in.
How to Install Docker on Fedora
Install prerequisites.
Add Docker software repository.
On some systems this will take some time to complete and might seem like it’s stuck. Don’t abort the operation. Of course, it might also really get stuck, but give it at least ten minutes to do its job on slower computers.
Enable auto-start of Docker at boot.
Start Docker.
Add yourself to the Docker group.
Log out and log back in to your graphical user interface.
People that also need Docker Compose can install it with:
How to Install Docker on Arch Linux
Arch already includes Docker in its community repositories, so the install procedure is easier here.
If you also need Docker Compose:
Add yourself to the Docker group:
Log out of the graphical user interface and log back in for the setting to take effect.
Enable Docker to automatically start at boot.
Start the Docker service.
Conclusion
Obviously, this doesn’t cover all distributions that are out there. But if you’re using something like openSUSE, you may be lucky enough to find an instruction page on how to install Docker on your distribution.
Fell in love with computers when he was four years old. 27 years later, the passion is still burning, fueling constant learning. Spends most of his time in terminal windows and SSH sessions, managing Linux desktops and servers.
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