Weather API (Flask + PostgreSQL + Docker + AWS EC2)

A RESTful Weather Data API built with Flask, PostgreSQL, Docker, and deployed on AWS EC2.

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Description

This project is a backend RESTful API system for managing weather data.

It fetches real-time weather data from an external API and stores it in a PostgreSQL database.
The system supports historical queries and conditional search functionality.

This project demonstrates a complete backend workflow including:

• API development (Flask)
• Database design (PostgreSQL)
• Containerized deployment (Docker)
• Cloud deployment (AWS EC2)

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Tech Stack

• Python
• Flask (RESTful API)
• PostgreSQL + psycopg2
• Docker / Docker Compose
• AWS EC2
• Linux (SSH)
• Git / GitHub

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System Architecture

Client -> Flask API -> PostgreSQL
           ↓
        Docker
           ↓
        AWS EC2

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Project Structure

weather_app/
├── app.py              # Entry point
├── api.py              # External weather API handling
├── db.py               # Database operations
├── Dockerfile
├── docker-compose.yml
├── requirements.txt
├── .env.example
└── .gitignore

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Environment Variables (.env)

This project uses a .env file to manage configuration.

1. Create .env

touch .env

2. Add configuration

cp .env.example .env

Then modify the values if needed.

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.env.example

It is recommended to provide an example file:

DB_HOST=db
DB_NAME=your_db_name
DB_USER=your_user_name
DB_PASSWORD=your_password
DB_PORT=5432

Do not upload .env to GitHub.

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API Endpoints

Method	Endpoint	Description
GET	/weather	Get current weather data and save it to database
GET	/history	Get recent weather history
GET	/history/search?date=YYYY-MM-DD	Search weather history by date

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Run with Docker

docker-compose up -d --build

Then open:

http://localhost:5000

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Deployment (AWS EC2)

1. Launch an EC2 instance (Ubuntu)
2. Install Docker and Docker Compose
3. Clone this repository:

git clone https://github.com/zhang-xian0531/weather_app.git
cd weather_app

4. Create the .env file
5. Start services:

docker-compose up -d --build

6. Configure AWS Security Group:
   • Allow inbound traffic on port 5000

Then access:

http://<EC2_PUBLIC_IP>:5000

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Features

• RESTful API design
• PostgreSQL database integration
• Modular architecture (API / DB separation)
• Docker containerization
• AWS EC2 cloud deployment
• Historical data query and filtering
• Environment-based configuration with .env

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Learning Outcomes

Through this project, I gained hands-on experience in:

• Backend API development with Flask
• Database design and integration with PostgreSQL
• Containerization with Docker and Docker Compose
• Linux server operation and SSH
• Cloud deployment using AWS EC2
• Environment variable management with .env
• Version control with Git and GitHub

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Author

• GitHub: https://github.com/zhang-xian0531