Kubernetes Lab - Webapp

Flask webapp demonstrating Kubernetes deployment patterns with Helm, Kustomize, and ArgoCD.

Quick Start

Prerequisites: Minikube, Helm, kubectl

minikube start --driver=docker

Alias (optional)

alias k=kubectl

Deployment Options

Helm (Default)

helm install webapp helm-webapp/ --values helm-webapp/values.yaml

k port-forward svc/webapp 8888:80
# Open: http://localhost:8888

Helm with Dev Overlay

k create namespace dev

helm install mywebapp-release-dev helm-webapp/ --values helm-webapp/values.yaml -f helm-webapp/values-dev.yaml -n dev

k port-forward svc/webapp 8888:80 -n dev
# Open: http://localhost:8888

Kustomize

Environment-specific overlays (config, replicas, patches applied to base).

kubectl apply -k kustom-webapp/overlays/prod

k port-forward svc/webapp 8888:80
# Open: http://localhost:8888

Static Manifests

kubectl apply -f Deployment/v1.yaml
kubectl apply -f Deployment/v2.yaml
kubectl apply -f Deployment/v3.yaml

k port-forward svc/webapp 8888:80
# Open: http://localhost:8888

Manage

# Expose via LoadBalancer (local)
minikube tunnel
k get svc

# Cleanup
helm uninstall webapp
helm uninstall mywebapp-release-dev -n dev

Project Structure

• helm-webapp/ - Helm chart with environment overlays
• kustom-webapp/ - Kustomize base + dev/prod overlays with replacements
• Deployment/ - Static manifests (v1-v3 progression)
• Dockerapp/ - Flask app source

Features

Security: Non-root user, read-only filesystem
Availability: HPA, PDB, rolling updates
Configuration: Immutable ConfigMaps, environment-specific overlays

ArgoCD Documentation

• ArgoCD GitOps Deployment - ConfigMap immutability pattern with ArgoCD

Troubleshooting

• Pods stuck in CrashLoopBackOff — Check logs: k logs <pod-name>
• Cannot access app — Ensure port-forward or minikube tunnel is running
• YAML files not recognized — Use .yaml extension (not .yml)