Docker for beginners: a step-by-step guide to installation and container deployment

Docker has become an essential tool for web developers, DevOps engineers, and other IT professionals. It allows you to package applications into containers along with all dependencies so they run reliably across different devices and operating systems.

Thanks to Docker, it’s possible to ensure reliable isolation of networks, file systems, and resources, avoid conflicts caused by incompatible environments, and prevent unauthorized access or data leakage.

What is Docker and why use it?

Docker is one of the most in-demand technologies in today’s IT landscape. Simply put, Docker is a platform that automates the deployment, scaling, and management of applications.

A Docker container packages an application together with all its dependencies and libraries into a single portable image. Virtualization in Docker is implemented at the OS level: it uses the host system’s kernel and runs isolated containers with minimal overhead.

The architecture includes components such as Docker Engine, Docker Images, Docker Containers, and Docker Hub.

Benefits:

• Portability. Containers run consistently across any server or cloud without changing the code.
• Lightweight and fast. Containers start in seconds and use fewer resources than virtual machines.
• Scalability. Works seamlessly with Kubernetes and Docker Swarm.
• Simplified development. Developers can work in identical environments across dev and production stages.
• Security and isolation. Each application runs in its own container, avoiding dependency conflicts.
• Version control. You can define exact versions of libraries and environments for consistent results.

Docker containers are ideal for IT professionals working with microservices-based applications.

Where to host Docker containers

When working with Docker, it’s not only important to build containers but also to host them in a reliable infrastructure. One solid option is PSB.Hosting.

Benefits of hosting containers with PSB.Hosting:

• Modern VPS servers powered by AMD Ryzen CPUs and NVMe storage.
• Support for all popular Linux distributions and Docker environments.
• Flexible pricing plans and fast deployment.

This solution is ideal for running Docker alongside Kubernetes or CI/CD pipelines — especially if you want full control without relying on cloud providers.

Installing Docker

On Windows

1. Go to the official Docker website.
2. Download the installation file for Windows.
3. Run the installer and follow the instructions. On the first launch, enable WSL 2 if prompted.

After installation, restart your computer and wait for Docker to fully load.

On macOS

1. Download the .dmg file from the official website.
2. Move Docker to the “Applications” folder.
3. Launch Docker Desktop and sign in.

On Linux (Ubuntu/Debian)

Before installing Docker on Linux (Ubuntu/Debian), update the apt package index:

sudo apt update

Then, install the required dependencies and import the GPG key. The system may show a message after each command.

Next, add the official Docker repository:

sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu focal stable"

Once done, you can proceed with installing Docker.

Common Docker commands

Docker commands let you manage containers, images, and networks. They all start with the docker keyword followed by a space. Here are the most frequently used commands:

• docker run — runs a container from an image;
• docker version — shows the installed version;
• docker ps — lists running containers;
• docker stop — stops a container;
• docker start — starts a previously stopped container;
• docker restart — restarts a container;
• docker rm — removes a container;
• docker rmi — removes an image.

These commands help users navigate Docker efficiently and manage containers more productively.

Working with containers and images

To get started, simply install Docker and run this test command:

docker run hello-world

This pulls a test image and launches a container that outputs a message confirming Docker is installed correctly.

Users can launch more complex containers too. Images are created using a Dockerfile — a text file containing step-by-step build instructions.

With these commands, users can manage containers efficiently. Docker also supports:

• Volumes — for storing data outside containers.
• Networks — for enabling communication between separate containers.

Using Docker Compose

Docker Compose is a tool for developing and running complex multi-container applications. It lets you define service configurations in a single YAML file and deploy everything with one command.

Core steps:

1. Create a Dockerfile for each service.
2. Create a docker-compose.yml file with service definitions.
3. Launch the project using: docker-compose up

Users can stop containers or remove volumes when needed. Docker Compose simplifies development and deployment of multi-component applications across different environments and reduces potential conflicts.

Real-world use of Docker

Users can take advantage of multi-stage builds to create smaller and more secure Docker images. These builds let you define instructions that reduce image size and improve security.

Docker is widely used in developing:

• Search engines.
• Email services.
• Educational and entertainment platforms.

It integrates with CI/CD pipelines — such as GitLab CI, GitHub Actions, and Jenkins — to automate application builds, deployments, and testing.

Docker is used by government agencies and private companies that manage large datasets and maintain constant interaction with clients and partners.

A solid understanding of Docker fundamentals and proper usage can help reduce development and testing costs for multi-container applications — while improving overall performance.