Weather App

The Weather App is a simple Flask-based web application designed to provide users with a 7-day weather forecast for any city. This project emphasizes DevOps practices with automated infrastructure provisioning, CI/CD pipelines, and Kubernetes deployment on AWS EKS.

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Tools in this project:

1. Self-Hosted GitLab: For Source Control Management (SCM).
2. Jenkins: For building and deploying the application with CI/CD pipelines.
3. Terraform: For provisioning infrastructure as code.
4. AWS (Amazon Web Services): As the cloud provider.
5. EKS (Elastic Kubernetes Service): For managing containerized applications.
6. DockerHub: As the container registry to store and manage Docker images.

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Table of Contents

1. Prerequisites
2. Installation and Setup
3. Usage
4. Infrastructure as Code (IaC) Details
5. Continuous Integration/Continuous Deployment (CI/CD) Pipeline
6. Kubernetes Deployment
7. Configuration
8. Testing
9. Contact Information
10. Acknowledgments

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Prerequisites

• Python: Version 3.11+
• Docker: Installed and running
• Kubernetes: kubectl configured for your cluster
• AWS CLI: Configured with appropriate access keys
• Terraform: Installed on your local machine
• Jenkins: Installed with Docker and Kubernetes plugins

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Installation and Setup

Local Setup

1. Clone the repository:

   git clone <repository-url>
   cd weather-app

2. Set up a virtual environment:

   python3 -m venv venv
   source venv/bin/activate
   pip install -r requirements.txt

3. Run the application locally:

   python src/app.py

4. Access the app at http://127.0.0.1:5000.

Docker Setup

1. Build the Docker image:

   docker build -t your-dockerhub-username/weather-app:latest .

2. Run the Docker container:

   docker run -d -p 5000:5000 your-dockerhub-username/weather-app:latest

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Usage

• Open the application in your browser.
• Enter a city name in the search bar to fetch the 7-day weather forecast.
• View day/night temperatures and humidity levels for the selected city.

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Infrastructure as Code (IaC) Details

Overview

• Cloud Provider: AWS
• Services Used:
  • EKS for Kubernetes cluster
  • VPC with subnets and NAT gateways

Tools

• Terraform: Used to provision the infrastructure.

Setup Instructions

1. Navigate to the Terraform directory:

   cd terraform

2. Initialize and apply Terraform:

   terraform init
   terraform apply

3. Configure kubectl to connect to the EKS cluster:

   aws eks update-kubeconfig --region <AWS_REGION> --name <CLUSTER_NAME>

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Continuous Integration/Continuous Deployment (CI/CD) Pipeline

I use two separate Jenkinsfiles, one for the Build Pipeline (build.Jenkinsfile) and another for the Deploy Pipeline (deploy.Jenkinsfile), which offers several benefits:

Separation of Concerns: Each file handles a distinct part of the pipeline: the build pipeline focuses on testing, building, and packaging the application, while the deploy pipeline manages the deployment process. This modular approach makes pipelines easier to manage and debug.

Flexibility: Separate Jenkinsfiles allow you to trigger the deploy pipeline independently of the build pipeline, enabling faster iterations and re-deployments without rebuilding the application.

Build Pipeline (build.Jenkinsfile)

• Stages:
  1. Cleanup
  2. Install Requirements
  3. Pylint Test
  4. Docker Build
  5. Smoke Test
  6. Tag and Push to DockerHub
  7. Trigger Deploy Pipeline

Deploy Pipeline (deploy.Jenkinsfile)

• Stages:
  1. Cleanup
  2. Deploy to EKS

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Kubernetes Deployment

Deployment Manifest (k8s-manifest/deployment.yaml)

• Deploys 2 replicas of the Weather App container.

Service Manifest (k8s-manifest/service.yaml)

• Exposes the app on a NodePort (port 5000).

Deployment Steps

1. Apply Kubernetes manifests:

   kubectl apply -f k8s-manifest/deployment.yaml
   kubectl apply -f k8s-manifest/service.yaml

2. Verify deployment:

   kubectl get pods -n weather-app
   kubectl get svc -n weather-app

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Configuration

Environment Variables

• APP_NAME: Application name
• REGISTRY_URL: DockerHub registry URL
• AWS_REGION: AWS region for deployment
• KUBECONFIG_CREDENTIALS_ID: Jenkins credentials ID for Kubernetes config

Configuration Files

• Terraform:
  • main.tf, vpc.tf, eks-cluster.tf: Define AWS infrastructure.
• Jenkinsfiles:
  • build.Jenkinsfile, deploy.Jenkinsfile: Define CI/CD pipelines.

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Testing

Unit Tests

1. Run Pylint for static code analysis:

   pylint src/*.py

2. Run Python unit tests:

   python -m unittest discover src/tests

Smoke Tests

1. Test app connectivity:

   python src/tests/check-connectivity.py

Selenium Tests

1. Ensure Selenium WebDriver is installed.
2. Run:

   python src/tests/test-selenium.py

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Contact Information

• Maintainer: Matan Kaufman
• Email: matankaufman1@gmail.com

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Acknowledgments

• OpenMeteo API: For weather data
• Terraform AWS Modules: For infrastructure setup
• Jenkins Community: For CI/CD support