Django ToDo List — Helm Chart Deployment

This repository contains a complete project for deploying a ToDo web application (built with the Django framework) to a Kubernetes cluster using a Helm Chart.

The main objective of this project is to demonstrate a reliable and scalable deployment of a multi-component application (web server and database) using modern Infrastructure as Code (IaC) and container orchestration practices.

🏗 Project Architecture

The project consists of the following main components:

• Web Application (Django): The backend that provides a REST API and an interactive UI (using Skeleton CSS and jQuery). The source code is located in the src/ directory.
• Database (MySQL): Stores user data and their task lists.
• Helm Chart (todoapp): The main chart for deploying the application and all required Kubernetes resources.
• Helm Sub-chart (mysql): A child chart for deploying the MySQL database (as a StatefulSet) with persistent data storage (Persistent Volumes).

⛵ Helm Chart todoapp

All infrastructure configuration is encapsulated within the Helm Chart. Key features and settings include:

• Configuration Flexibility: All crucial parameters, such as Namespace names, resource names (generated automatically using .Chart.Name), database connections, and secrets, are extracted and managed through the values.yaml file.
• Secrets and Environment Variables Management: The range function is used to dynamically generate secrets data and conveniently map them into Environment Variables inside the Deployment.
• Scaling and HPA: A Horizontal Pod Autoscaler (HPA) is configured to automatically scale pods based on resource utilization (e.g., target CPU and memory utilization is configured in values.yaml).
• Resource Allocation: Clearly defined requests and limits for CPU and RAM to ensure stable operation within the cluster.
• High Availability:
  • RollingUpdate parameters are configured for seamless updates.
  • Affinity, Node Affinity, and Tolerations are set (e.g., to schedule the database on specific nodes with app=mysql taints and labels).
• Data Persistence: A PersistentVolumeClaim (PVC) is used for reliable MySQL data storage with specified capacity requirements.
• Security: Access to the Kubernetes API is restricted using ServiceAccount and corresponding RBAC objects.

🚀 Installation and Deployment

Prerequisites:

• Docker installed
• A Kubernetes cluster (we recommend kind)
• Helm and kubectl installed

Deployment Steps:

1. Create the cluster: For local testing, you can spin up a cluster using the provided cluster.yml configuration file:

   kind create cluster --config cluster.yml

2. Prepare nodes (Taints/Labels): Assign the appropriate labels and taints to the database node to ensure correct pod scheduling:

   kubectl taint nodes <node-name> app=mysql:NoSchedule

3. Deploy using the automated script: For a quick start, you can use the bootstrap.sh script, which contains all the necessary commands to deploy prerequisites and the todoapp Helm Chart to your cluster:

   ./bootstrap.sh

🛠 Local Web Application Development

If you want to run the Django application locally (outside of Kubernetes):

1. Go to the source directory and install the dependencies (Python 3.8+ required):

   cd src
   pip install -r requirements.txt

2. Run database migrations:

   python manage.py migrate

3. Start the development server:

   python manage.py runserver

   The application will be available at: http://localhost:8000/ (API is available at /api/).