Introduction to Kubernetes

What is Kubernetes?

Kubernetes (K8s) is a powerful tool that helps manage and run applications in **containers**. Think of it as a **smart manager** that makes sure your apps are always running, even if something crashes. It helps deploy, scale, and manage applications **automatically**.

Why Use Kubernetes?

Imagine you are running a website, and suddenly **a lot of users visit it**. With Kubernetes, your app can **automatically create more servers** to handle the load. And when traffic goes down, it removes unnecessary resources, **saving money and effort**.

How Does Kubernetes Work?

Kubernetes runs applications inside **Pods** (which are like small, self-contained boxes). These Pods run on **Worker Nodes**, and everything is controlled by a **Master Node**.

Basic Components of Kubernetes

Here are some important parts of Kubernetes:

  • Pod: The smallest unit that holds a container.
  • Deployment: Ensures the right number of Pods are running.
  • Service: Makes the application accessible over the network.
  • ConfigMap & Secret: Stores environment variables and sensitive data securely.
  • Persistent Volume (PV): Provides long-term storage for data.

How to Install Kubernetes?

Kubernetes can be installed in different ways, depending on where you want to run it:

  • Minikube: Best for local testing on your own computer.
  • Kind: Runs Kubernetes in Docker containers.
  • Cloud Services: Providers like Google Kubernetes Engine (GKE), Amazon EKS, and Azure AKS manage everything for you.

Creating Your First Kubernetes Pod

Let’s create a simple Pod that runs **Nginx** (a web server). Save this YAML file as pod.yaml.

apiVersion: v1
kind: Pod
metadata:
  name: my-first-pod
spec:
  containers:
  - name: my-container
    image: nginx

Apply this file using the command:

kubectl apply -f pod.yaml

Checking the Status of Your Pod

Once deployed, you can check if your Pod is running:

kubectl get pods

Conclusion

Kubernetes is an essential tool for managing modern applications. It helps ensure your app is always running, automatically scales when needed, and makes deployments easier.

In the next lesson, we will explore **Kubernetes Architecture**, where we will discuss how the different parts of Kubernetes work together.