Why advanced patterns matter in Kubernetes - See It in Action

Why Advanced Patterns Matter in Kubernetes

📖 Scenario: You are managing a small web application deployed on Kubernetes. Initially, you used simple deployment patterns, but as your app grows, you notice issues with scaling, updates, and reliability.This project will guide you through creating a Kubernetes Deployment manifest, adding configuration for rolling updates, applying advanced patterns like readiness probes, and finally checking the deployment status.

🎯 Goal: Build a Kubernetes Deployment manifest that uses advanced patterns such as rolling updates and readiness probes to improve application reliability and update safety.

📋 What You'll Learn

Create a basic Deployment manifest with one replica

Add a configuration for rolling update strategy

Add a readiness probe to the container spec

Display the deployment status using kubectl command

💡 Why This Matters

🌍 Real World

Advanced Kubernetes patterns help keep applications running smoothly during updates and scale changes, preventing downtime and improving user experience.

💼 Career

Understanding these patterns is essential for DevOps engineers and site reliability engineers to manage production Kubernetes clusters effectively.

1

Create a basic Deployment manifest

Create a Kubernetes Deployment manifest named webapp-deployment.yaml with apiVersion: apps/v1, kind: Deployment, metadata name webapp, and spec with replicas: 1. The pod template should have a container named webapp-container using image nginx:1.21.

Kubernetes

# Your code here

Need a hint?

Start by defining the Deployment with one replica and a container running nginx version 1.21.

2

Add rolling update strategy configuration

Add a strategy section under spec with type RollingUpdate. Set maxUnavailable to 25% and maxSurge to 25% to control rolling updates.

Kubernetes

apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp
spec:
  replicas: 1
  # Add rolling update strategy below
  selector:
    matchLabels:
      app: webapp
  template:
    metadata:
      labels:
        app: webapp
    spec:
      containers:
      - name: webapp-container
        image: nginx:1.21

Need a hint?

Under spec, add strategy with rolling update settings to control how pods update.

3

Add a readiness probe to the container

Inside the container spec, add a readinessProbe that uses an httpGet on path / at port 80. Set initialDelaySeconds to 5 and periodSeconds to 10.

Kubernetes

apiVersion: apps/v1
kind: Deployment
metadata:
  name: webapp
spec:
  replicas: 1
  strategy:
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 25%
      maxSurge: 25%
  selector:
    matchLabels:
      app: webapp
  template:
    metadata:
      labels:
        app: webapp
    spec:
      containers:
      - name: webapp-container
        image: nginx:1.21
        # Add readinessProbe here

Need a hint?

Add a readiness probe inside the container spec to check if the app is ready by sending HTTP GET requests.

4

Display the deployment status

Run the command kubectl rollout status deployment/webapp to display the rollout status of the webapp deployment.

Kubernetes

# Run the kubectl command below
# Your code here

Need a hint?

Use kubectl rollout status deployment/webapp to check if the deployment is successful and pods are ready.