Docker 101: What the Fuzz Is It, and Why You Should Care!?
So you’ve heard about Docker—maybe your friend's talking about "containers," or you saw a tutorial with commands like docker run hello-world. But what the heck is it, and why is everyone so obsessed with it? Let’s break it down in plain language.
What Docker Actually Is?
At its core, Docker is a tool that packages an application and all its dependencies into a neat little app called a container. The name comes from shipping containers: just like a shipping container holds goods securely and can be transported anywhere, a Docker container holds everything an app needs and can be moved seamlessly between systems.
Each container runs isolated from your host system and other containers, including code, libraries, and configuration files. You can run, stop, move, or replicate containers exactly the same way on any system with Docker installed.
In short, a container is like a "portable app" that works on any Linux server, cloud instance, or your laptop—without breaking a sweat.
Why Use Docker?
Here’s why people love it:
- Isolation – Containers run independently, so they don't interfere with your OS or each other.
- Portability – The same container works anywhere: your laptop, a VPS, or a cloud server.
- Consistency – The app runs the same way everywhere, no surprises.
- Efficiency – Containers share the host kernel, making them much lighter than traditional virtual machines.
- Easy upgrades & rollbacks – Pull the latest image for an upgrade, or roll back if something breaks.
Docker vs Traditional Installations
When installing software on Linux, you generally have two main approaches: using Docker containers or performing a traditional installation via APT or manual methods (source code and compiling). Each approach has its pros and cons, from how isolated the software is to how easy it is to upgrade or move between systems.
The table below highlights the key differences between those approaches.
| Feature | Docker (Containers) | Traditional Install (APT / Manual) |
|---|---|---|
| Isolation | High – containers isolated from host | Low – conflicts possible |
| Portability | High – same container runs anywhere | Low – depends on host OS & libs |
| Upgrades | Easy – pull new image | Can break dependencies |
| Resource use | Slight overhead (container engine) | Minimal – runs directly on OS |
| Learning curve | Moderate – Docker knowledge needed | Easy for Linux users |
| Dependency management | All included in container | Must manage manually |
| Rollback | Simple – revert to previous image | Harder – manual patching |
| Networking | Virtual network between containers | Native host networking |
Installing Docker on Ubuntu 24.04
Pro Tip: Always use Docker's official repository instead of Ubuntu's defaultdocker.io.
This way, you'll get the latest stable version with all the fixes and features.
1️. Update your system
$ sudo apt update && sudo apt upgrade -y
2️. Remove old Docker versions (if any)
$ sudo apt remove docker docker-engine docker.io containerd runc
3️. Install dependencies
$ sudo apt install apt-transport-https ca-certificates curl software-properties-common -y
This sets up your system to securely download software from external repositories.
4️. Add Docker’s official GPG key
$ sudo mkdir -p /etc/apt/keyrings
curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg
$ sudo chmod a+r /etc/apt/keyrings/docker.gpg
These steps securely add Docker's signing key so your system can trust and install Docker packages.
5️. Add Docker repository
$ echo "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null
This command adds Docker's official repository to your system so you can install the latest Docker packages securely.
6️. Install Docker Engine & CLI
$ sudo apt update
$ sudo apt install -y docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin
These commands update your system and install Docker with all the essential tools to build, run, and manage containers.
7️. Enable and start Docker
$ sudo systemctl enable docker
$ sudo systemctl start docker
8️. Verify installation
$ docker --version
$ docker version
$ sudo systemctl status docker
You should see something like:
Docker version 29.0.2, build 8108357
Client: Docker Engine - Community
Version: 29.0.2
API version: 1.52
Go version: go1.25.4
Git commit: 8108357
...
..
.Basic Docker Commands
- List running containers:
docker ps - List all containers:
docker ps -a - Start/Stop/Restart a container:
docker start|stop|restart <container_name> - View logs:
docker logs <container_name> - Follow logs live:
docker logs -f <container_name> - Enter a container shell:
docker exec -it <container_name> /bin/zsh - List images:
docker images - Remove container/image:
docker rm <container_name>,docker rmi <image_name> - Docker Compose up/down:
docker compose up -d,docker compose down - Check disk usage:
docker system df
We hope this guide helps you get Docker up and running with confidence! Happy tweaking!
Docker really is a game-changer for running apps reliably. Once you wrap your head around containers, images, and Compose files, managing multi-service applications becomes smooth and predictable.
Stay tuned for more tips and tutorials on Docker in future posts!
