Herco Bezuidenhout
Understanding Docker & Kubernetes: A Beginner’s Guide
Mar 05, 2025Introduction
I have recently been working with Docker & Kubernetes on one my projects (also Helm, ArgoCD, etc.) and I want to put some effort into understanding it more. Below is notes from what I have gathered so far. I will continue to post as I learn, experiment and fail.
What is Docker?
Docker is a tool that allows you to package and run applications in containers. A container includes everything an app needs—code, libraries, and dependencies—so it works the same anywhere.
Key Docker Concepts
- Docker Image 🏗️ → A blueprint/template for a container. It can be reused to create multiple containers.
- Docker Container 📦 → A running instance of an image. It runs the app with its dependencies.
- Dockerfile 📜 → A script that defines how to build a Docker image.
- Docker Compose 🔄 → A tool to configure and manage multiple containers on a single machine using a
docker-compose.ymlfile.
Docker vs. Kubernetes vs. Docker Compose
| Feature | Docker Compose | Kubernetes |
|---|---|---|
| Purpose | Manages multiple containers on a single machine. | Orchestrates containers across multiple machines. |
| Scalability | Limited to one machine. | Scales across clusters of servers. |
| Complexity | Simple & easy to set up. | More complex but powerful. |
| Use Case | Local development & small projects. | Large-scale, distributed applications. |
Can Kubernetes Run on a Single Machine?
Yes! You can run Kubernetes on a single machine using Minikube, K3s, or Kind.
Can One Container Have Multiple Images?
No, a container runs from a single image, but multiple containers can communicate with each other.
Final Thoughts
- Use Docker to containerize applications.
- Use Docker Compose for managing multiple containers locally.
- Use Kubernetes for scaling containers across multiple machines.
By understanding these basics, you’ll be well on your way to mastering containerized applications! 🚀