QA: Kubernetes Basics – A Beginner’s Guide

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1. What is Kubernetes?

Kubernetes (often called K8s) is an open-source system for managing containers (like Docker). Think of it as an orchestra conductor: it makes sure all your applications (containers) run where they should, scale up when needed, and stay healthy.

2. Why use Kubernetes?

• Scalability: Automatically add or remove resources depending on demand.
• Reliability: If something crashes, Kubernetes restarts it.
• Portability: Runs on cloud, on-premises, or hybrid environments.
• Efficiency: Uses resources more effectively than manual deployment.

3. Key Concepts

Here are the main building blocks of Kubernetes:

• Cluster
  A group of machines (servers) that run your applications.

• Node
  A single machine inside the cluster. It can be physical or virtual.

• Pod
  The smallest unit in Kubernetes. A pod usually runs one container, but it can hold multiple tightly connected containers.

• Deployment
  A set of instructions that tells Kubernetes how to run and manage pods (e.g., “run 3 copies of this app”).

• Service
  A stable network address to connect to your pods, even if they move around between nodes.

• Namespace
  A way to organize resources into separate “folders” within the cluster.

4. How Kubernetes Works (Simple View)

1. You define what you want (for example: “run 5 copies of my web app”).
2. Kubernetes schedules pods on available nodes.
3. If a pod fails, Kubernetes restarts or replaces it.
4. If demand increases, Kubernetes scales up automatically.
5. Networking and load balancing are handled in the background.

5. Typical Workflow

1. Write a manifest (usually a .yaml file) that describes your app.
2. Apply the manifest with kubectl apply -f file.yaml.
3. Kubernetes creates and manages the resources.
4. You can check status with kubectl get pods or kubectl get services.

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Want to go deeper? Check out the follow-up guide: “Next Steps in Kubernetes – From Basics to Practice”, where we cover kubectl commands, writing simple YAMLs, scaling, and monitoring.