Docker for Beginners: An Easy Guide to Understanding and Using Docker on Servers and Workstations

Docker is an open-source platform that allows you to automate the deployment of applications inside lightweight, isolated environments known as containers. We have an article on Containers in Servers from a while back, should you want a bit more information on containers in the server space. But think of a container as a package that bundles everything an application needs to run, including code, libraries, and settings. Containers are highly portable, meaning they can run consistently on different machines, whether it’s a server in the cloud or a workstation in your office.

Containers are different from virtual machines (VMs) in that they don’t require a full operating system to run, which makes them more efficient in terms of resources and speed. While a VM might contain its own OS kernel, containers share the host system’s kernel, using less memory and storage and makes containers much easier to deploy consistently across machines or environments.

Why Use Docker for Servers and Workstations?

Docker on Servers

Docker is highly beneficial for server environments where multiple applications or services run side by side. It simplifies application deployment, making it easier for developers to manage updates and changes across various machines. Additionally, because containers are isolated, they help reduce potential conflicts between applications, increasing security and system stability.

Docker on Workstations

Docker is equally valuable on workstations for testing, development, and running various applications without cluttering the main system. Developers can use Docker to test different versions of software without worrying about compatibility issues. This makes it ideal for creating clean, reproducible environments for coding, data science, or simply running isolated apps without affecting other software on the machine.

Benefits of Using Docker

Here are some of the main advantages of Docker:

Portability: Docker containers can run on any platform that supports Docker, whether it’s Linux, Windows, or macOS, making applications easier to distribute.
Efficiency: Because containers share the host system’s kernel, they use fewer resources than traditional VMs, making them faster to start and more efficient to run.
Isolation: Each Docker container runs in its own environment, minimizing compatibility issues and preventing conflicts.
Scalability: Docker can easily scale to meet increasing demand by adding more containers or orchestrating with tools like Kubernetes.

Considerations When Using Docker

While Docker offers numerous advantages, there are a few things to keep in mind:

Data Persistence: Containers are generally ephemeral, meaning data inside them is not stored permanently. To persist data, you need to set up volumes or use other data management techniques.
Security: Docker relies on the host’s kernel, which can lead to security vulnerabilities if not properly managed. Regular updates and proper permissions are essential.
Learning Curve: Although Docker is powerful, it can take time for new users to learn. Understanding basic commands, configurations, and Dockerfile syntax may require some effort.

Installing Docker on Linux

To install Docker on Linux, follow these steps:

Update the System:
sudo apt update
Install Required Packages:
sudo apt install apt-transport-https ca-certificates curl software-properties-common
Add Docker’s GPG Key:
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /usr/share/keyrings/docker-archive-keyring.gpg
Add the Docker Repository:
eecho "deb [arch=$(dpkg --print-architecture) 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
Install Docker:
sudo apt update sudo apt install docker-ce
Verify the Installation:
docker --version

For the latest install instructions, please visit the Official Docker Install Docs

Installing Docker on Windows

To install Docker on Windows, follow these steps:

Download Docker Desktop for Windows from the Docker website.
Run the Installer and follow the setup instructions.
Choose Installation Type (details below) – you’ll have options for Hyper-V or WSL 2 (Windows Subsystem for Linux).
Finish the Installation and restart your computer.
Launch Docker Desktop to start using Docker on Windows.

Hyper-V vs. WSL 2 for Docker on Windows

When installing Docker on Windows, you have two main options: Hyper-V and WSL 2.

Hyper-V: This is a virtualization technology built into Windows, allowing Docker to run containers inside a virtual machine. This setup works well but has higher resource requirements, which can affect system performance. Additionally, Hyper-V is only available on Windows 10/11 Pro or Enterprise.
WSL 2: The Windows Subsystem for Linux version 2 is a compatibility layer that enables a full Linux kernel to run on Windows, making it more efficient for Docker containers. WSL 2 generally offers faster performance than Hyper-V and is available on all versions of Windows 10 and Windows 11. Many developers prefer WSL 2 for a smoother Docker experience on Windows. PROTIP: Should you install Docker to use WSL2, please remember that your resource usage (specifically memory) will be more due to the WSL running constantly, even when you are not using Docker. You can switch off WSL and/or disable autostart to save some RAM. This is especially important for machines with less memory. To shut down WSL run the command wsl --shutdown in your terminal of choice.

Use Cases for Docker

Here are a few scenarios where Docker can be especially useful:

Application Deployment: For deploying applications consistently across different servers without compatibility issues.
Testing and Development: Run multiple versions of an application or test software in isolated environments on a workstation.
Data Science and Machine Learning: Package dependencies and environments to ensure compatibility for complex data analysis pipelines.
Microservices Architecture: Run each component of a system in a separate container for easier management, scaling, and debugging.

Summary

Docker is a powerful tool that leverages containers to run applications in isolated, lightweight environments. It’s popular both in server environments, where it simplifies deployment and scaling, and on workstations, where it helps developers manage clean environments. Docker’s flexibility, portability, and efficiency make it a valuable tool, though considerations like data persistence and security require attention.

For installation, Linux users can follow a few straightforward commands, while Windows users can choose between Hyper-V and WSL 2 options based on their needs and resources. Docker’s use cases range from development and testing to deploying applications and supporting microservices, making it an essential tool for modern computing.

With this guide, you’re ready to explore Docker and discover the convenience and efficiency it brings to managing applications across diverse environments.