Modern Infrastructure – Part 2: Kubernetes

Introduction

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In the evolving world of cloud-native applications, containerization has revolutionized how we build, ship, and run software. But as the number of containers in a project grows, managing them becomes a challenge. That’s where Container Orchestration steps in - and Kubernetes is the undisputed leader in this space.

What is Container Orchestration?

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Container orchestration is a way to automate the deployment, scaling, and management of many containers.

Instead of starting and stopping each container manually, orchestration tools (like Kubernetes) handle it for you - making sure your apps run smoothly, restart if they crash, and scale when needed.

It’s like having a smart system that keeps all your containerized apps organized and running the way you want, across multiple machines.

What Is Kubernetes?

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Kubernetes (K8s) is an open-source platform that automates deploying, scaling, and managing containerized applications.

Originally built by Google and now maintained by the Cloud Native Computing Foundation (CNCF), it enables:

• Automatic container scheduling

• Load balancing

• Self-healing and auto-scaling

• Service discovery

Why Minikube and kubectl?

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To run Kubernetes on your local machine, you need two key tools:

1. kubectl - The Kubernetes Command-Line Tool

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kubectl is the primary way to interact with a Kubernetes cluster. You use it to:

• Deploy applications

• Inspect and manage cluster resources

• View logs

• Scale deployments

• Expose services

Without kubectl, you cannot communicate with your cluster’s API server or manage any workloads.

Think of `kubectl` as your terminal interface to Kubernetes - just like git is to version control.

2. Minikube - Local Kubernetes Cluster

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Minikube is a lightweight tool that sets up a single-node Kubernetes cluster on your machine. It’s ideal for:

• Learning Kubernetes basics

• Local development

• Testing configuration files before production

Prerequisites

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Make sure you have:

• A system with virtualization enabled (Docker, VirtualBox, etc.)

• Terminal access with sudo privileges

• Internet connection

Step-by-Step Installation Guide (Ubuntu/Linux)

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Step 1: Install kubectl

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1. Downlaod the latest stable version:

   

2. Then make the file executable with:

   

3. Move it to your system’s binary path by:

   

4. Check the version if it is installed successfully:

   

Step 2: Install minikube

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1. Downloa the minikube binary:

   

2. Install it to your system path:

   

3. Check version:

   

Step 3: Start the Kubernetes Cluster

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1. Recommended: Choose a driver (Docker is common):

   

2. Optional: this command automatically selects the best available driver on your system (e.g., Docker, VirtualBox, KVM):

   

This downloads the required components and spins up a single-node cluster.

Step 4: Verify the Cluster is Running

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Step 5: Interact with Your Cluster

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You should see one node in a Ready state.

Step 6: Deploy a Sample App

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Do you have a deployment?

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If there’s no output, create one:

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Option 1:

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Through kubernetes CLI (kubectl):

kubectl create deployment hello-node --image=k8s.gcr.io/echoserver:1.4

Option 2:

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Using the Kubernetes Dashboard (Optional UI):

1. Lanch the minikube dashboard:

   

2. If the output says somethin like:

No resources found in kubernetes-dashboard namespace.

It means the dashboard pods haven’t been created yet - so naturally, proxy health will hang since there’s nothing to proxy to.

How to Fix it: Manually Enable the Dashboard Addon

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Minikube is supposed to auto-enable it with minikube dashboard, but sometimes it silently fails. You can force it like this:

Then manually install the metrics scraper (recommended for full functionality):

Wait and Watch:

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Then watch pods getting created:

Once Running:

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Launch the dashboard again:

minikube dashboard

Boom! You’re in the Kubernetes Dashboard - mission accomplished! This means your entire Minikube cluster is working exactly as it should.

What You Can Do From Here

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Now that you’re inside the dashboard UI, here are a few things worth exploring:

1. Workloads

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• Check out: Deployments, Pods, ReplicaSets

• Try creating a sample deployment from the UI

2. Create a Deployment

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Use the “+” button (top-right) or go to:

• + CREATE → Deploy a containerized app

I did this simple yaml:

apiVersion: apps/v1
kind: Deployment
metadata:
name: hello-node
spec:
replicas: 1
selector:
 matchLabels:
   app: hello
template:
 metadata:
   labels:
     app: hello
 spec:
   containers:
   - name: hello
     image: k8s.gcr.io/echoserver:1.10
     ports:
     - containerPort: 8080

3. Expose a Service

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You can expose your deployment right from the dashboard as a NodePort

-then open it in a browser using:

This will:

• Create a Service named hello-node

• Expose port 8080 of your pod

• Assign a random NodePort between 30000–32767

To access the app:

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It should open in your browser!

Stopping or Cleaning Up

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1. When you’re done, you can stop the cluster:

minikube stop

2. To delete the cluster entirely:

minikube delete

Conclusion

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Kubernetes might seem complex at first, but starting with a local setup helps demystify it. By running a cluster on your own machine using Minikube, you gain the confidence to move to production environments later.

Kubernetes isn’t just a tool - it’s a platform that empowers you to build resilient, scalable, and manageable applications at scale.

"Learning Kubernetes is like learning how to drive a spaceship. But once you do, you're ready to explore galaxies."

Commands List

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curl -LO "https://dl.k8s.io/release/$(curl -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"

chmod +x kubectl

sudo mv kubectl /usr/local/bin/
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kubectl version --client

curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64

sudo install minikube-linux-amd64 /usr/local/bin/minikube

minikube version

minikube start --driver=docker

minikube status
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kubectl get nodes

minikube dashboard
##or
minikube dashboard --url

kubectl create deployment hello-node --image=k8s.gcr.io/echoserver:1.4

minikube addons enable dashboard

minikube addons enable metrics-server
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kubectl get pods -n kubernetes-dashboard -w

kubectl expose deployment hello-node --type=LoadBalancer --port=8080

kubectl get service hello-node

minikube service hello-node