zkt25/sk1

Calculator Web Application on Azure Kubernetes Service (AKS)

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Application Description

This project is a simple web-based calculator that performs basic mathematical operations. It allows users to calculate expressions and save the results. A "Show History" button displays previously saved calculations.

Built with:

• Frontend: HTML/CSS/JavaScript served via Nginx
• Backend: Flask (Python) application connected to a PostgreSQL database
• Database: PostgreSQL 15

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Public Cloud Environment

• Provider: Microsoft Azure
• Service Used: Azure Kubernetes Service (AKS)
• Certificate Issuer: cert-manager with Let's Encrypt
• Domain: https://aliscloudwork.tech

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Kubernetes and Cloud Components

• Deployments: - Frontend Deployment (Nginx server) - Backend Deployment (Flask server) - PostgreSQL Deployment (Database server)

• Services: - Frontend Service (ClusterIP) - Backend Service (ClusterIP) - PostgreSQL Service (ClusterIP) - Ingress Controller Service (LoadBalancer)

• Ingress: - Ingress resource used to route traffic and enable HTTPS

• Persistent Volume: - PostgreSQL database uses a Persistent Volume Claim (PVC) for data persistence

• Certificate Management: - cert-manager with Let's Encrypt to generate HTTPS certificates automatically

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Azure CLI Setup Steps

1. Create a Resource Group

az group create --name aks-calculator-rg --location westeurope```
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2. Create AKS Cluster (basic version, no AGIC yet)
az aks create \
  --resource-group aks-calculator-rg \
  --name calculatorAKS \
  --node-count 1 \
  --enable-managed-identity \
  --generate-ssh-keys
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3. Connect kubectl to Your AKS Cluster

az aks get-credentials --resource-group aks-calculator-rg --name calculatorAKS
kubectl get nodes
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Example output:

shane@Ali-DESKTOP:~/assinments/cal$ kubectl get nodes
NAME                                STATUS   ROLES    AGE     VERSION
aks-nodepool1-21170036-vmss000000   Ready    <none>   5m42s   v1.31.7
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Files Included

prepare-app.sh: Script to deploy all Kubernetes objects and services automatically

remove-app.sh: Script to delete all Kubernetes objects and services

kubi/*.yaml: Kubernetes deployment, service, ingress, PVC configuration files

backend/Dockerfile: Dockerfile for the Flask backend application

frontend/Dockerfile: Dockerfile for the Nginx frontend application

frontend/default.conf: Nginx configuration file for routing

README.md: This documentation file

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How to View and Use the Application
Open a web browser and visit: https://aliscloudwork.tech

Use the calculator to perform operations.

Click the "Show History" button to view saved calculations.

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Running Scripts
To deploy the application:
- bash prepare-app.sh

To delete the application:
- bash remove-app.sh

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xternal Sources and Tools Used
DockerHub for container images

Let's Encrypt for SSL certificates

cert-manager for Kubernetes certificate automation

Azure CLI for AKS management

Official documentation for Nginx, Flask, Kubernetes YAML syntax


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Final Notes
HTTPS is fully functional.

Kubernetes ensures all components are modular and recover automatically.

Database uses persistent storage for calculation history.