Getting Started with Docker

Docker is a platform for automating the deployment, scaling, and management of applications using container technology. Containers are a lightweight alternative to virtual machines, allowing developers to package an application and all its required dependencies into a single executable unit that can run on any system with Docker installed.

History and Concept

Docker was first released in 2013 by dotCloud, which later renamed itself to Docker, Inc. The core idea was to create a universal way to package applications so that they would run identically in any environment — whether a developer’s local machine, a test environment, or a cloud platform. This was achieved through containerization technology, which allows the operating system to be split into many isolated processes.

Advantages of Docker

Portability: Developers can build container images that contain everything needed to run an application, and these can run on any machine without additional configuration.
Isolation: Each container runs in its own isolated environment, which minimizes conflicts between applications and their dependencies.
Resource efficiency: Containers use resources more efficiently than traditional virtual machines because they share a single operating system, reducing overhead.
Fast development and deployment: With Docker, the software supply chain becomes faster and more reliable, since the build, test, and deployment processes are automated and standardized.
Scalability: Docker integrates easily with many orchestration systems, such as Kubernetes, making it easier to manage large container clusters.

Docker revolutionized the world of software development by providing tools that greatly simplify the process of building and deploying applications. Thanks to its flexibility and convenience, it has become an industry standard and continues to evolve, offering new ways to optimize and manage IT infrastructure.

Installing Docker

Let’s look at installation on Ubuntu 24.04, the most popular distribution in 2025.

If you previously had Docker installed, or have old plugins installed, you need to remove them using the script below.

for pkg in docker.io docker-doc docker-compose docker-compose-v2 podman-docker containerd runc; do sudo apt-get remove $pkg; done

Add the APT repository:

# Add Docker's official GPG key:
sudo apt-get update
sudo apt-get install ca-certificates curl
sudo install -m 0755 -d /etc/apt/keyrings
sudo curl -fsSL https://download.docker.com/linux/ubuntu/gpg -o /etc/apt/keyrings/docker.asc
sudo chmod a+r /etc/apt/keyrings/docker.asc

# Add the repository to Apt sources:
echo \
  "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.asc] https://download.docker.com/linux/ubuntu \
  $(. /etc/os-release && echo "$VERSION_CODENAME") stable" | \
  sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
sudo apt-get update

Install Docker and the necessary plugins:

sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin

Verify that the installation was successful by running the hello-world image:

sudo docker run hello-world

By default, Docker has to be run with sudo privileges; you can work around this by adding your user to the docker group.

Create the docker group if it doesn’t exist:

sudo groupadd docker
sudo usermod -aG docker $USER
newgrp docker

Verify that Docker works without sudo privileges:

docker run hello-world

For Docker to start when the system boots, you need to enable the services:

sudo systemctl enable docker.service
sudo systemctl enable containerd.service

Congratulations! You’ve installed Docker and can now run and manage containers on your server.

You can learn more in the official Docker documentation here.