🌦️ Weather API (GraphQL + Go + Redis)

A GraphQL-based weather API built with Go that fetches real-time and historical weather data from Visual Crossing. The API supports querying by city and optional date, caches responses using Redis, and applies rate limiting using API keys to prevent abuse. This is my project following https://roadmap.sh/projects/weather-api-wrapper-service.

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🚀 Features

• 🔍 GraphQL API using gqlgen
• 🌦️ Fetch weather data by city and optional date (defaults to today)
• ⚡ Caching with Redis to avoid redundant external API calls
• 🛡️ Rate Limiting based on API keys to prevent abuse
• 📆 Query by City & Date (defaults to current date if not provided)
• 🐳 Docker-based Redis setup
• 🛠️ Developer-friendly with VSCode debug support

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📦 Prerequisites

• ✅ Go installed (Download Go)
• ✅ Docker installed (Install Docker)
• ✅ Redis running locally (or via Docker)
• ✅ Visual Crossing API Key from: https://www.visualcrossing.com

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🔧 Technologies Used

• Golang
• gqlgen
• Redis
• Docker
• Visual Crossing Weather API
• GraphQL

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🖼️ Architecture Diagram

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📦 Setup Instructions

1. Clone the Repository

git clone https://github.com/Agarwalsahil/weather-api.git
cd weather-api

2. Install Go dependencies

go mod tidy

3. Generate GraphQL code (from schema)

go run github.com/99designs/gqlgen generate

4. Set the Environment Variable

💻 For local run (Linux/macOS):

# 💻 On Linux/macOS:
export WEATHER_API_KEY=your_key_here

# 🪟 On Windows (cmd):
set WEATHER_API_KEY=your_key_here

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▶️ Running the Project

go run server.go

Server starts on: http://localhost:8080

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🧠 For Debugging in VSCode (launch.json):

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "weather-api",
      "type": "go",
      "request": "launch",
      "mode": "auto",
      "program": "${workspaceFolder}/server.go",
      "env": {
        "WEATHER_API_KEY": "Your Api Key"
      },
      "args": []
    }
  ]
}

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🧪 Sample GraphQL Query

query {
  getWeatherData(city: "New Delhi") {
    latitude
    longitude
    resolvedAddress
    days {
      temp
      tempmax
      windgust
      windspeed
    }
    isProcessed
  }
}

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🗃️ Redis Caching Strategy

• Key: ${city}:${date}
• Checks Redis cache first.
• If not found → Fetch from external API → Store result in cache → Return response.

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🔐 Rate Limiting

• API key must be passed in request headers:

  {
    "X-API-Key": "your-api-key"
  }

• Requests without valid API key are denied.

• Rate limits configurable (e.g., max 5 req/min per key).

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🐳 Docker (for Redis)

docker run --name weather-api-redis -p 6379:6379 -d redis

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🧠 Contributing

Pull requests are welcome! For major changes, open an issue first to discuss what you'd like to change.

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👨‍💻 Author

Built with ❤️ using Go and GraphQL
By [Sahil Agarwal]