CKAD 01 — Image and Container Management in Kubernetes

Photo by Olav Ahrens Røtne on Unsplash

Container management is a crucial skill for anyone working with Kubernetes. Containers allow applications to run consistently across environments by packaging code, dependencies, and configurations into a single, portable unit. In Kubernetes, managing these container images — defining, building, and modifying them — is essential, especially for CKAD certification.

In this guide, we’ll go through practical steps to build and run a container image for a Node.js application. By following along, you’ll understand how to create an image, run a container, and interact with it using Docker commands. The exercise includes commands and explanations to clarify each action.

Prerequisites

• Docker or another container runtime like Podman or BuildKit installed.
• A Kubernetes Cluster: For local testing, you can use Minikube or access a lab environment like O’Reilly’s interactive lab.

The exercise is based on a Node.js application. If you don’t have this setup, please check this repository.

Key Concepts

1. Container Image: A pre-packaged unit containing the application code, runtime, libraries, and environment variables needed to run an application.
2. Containerfile (Dockerfile): A…