Weather API Service

A Go-based weather API service that provides weather updates via email subscriptions. Users can subscribe to receive weather updates for their preferred cities either hourly or daily.

🚨 Please be aware that site is deployed at https://weatherapi-rpum.onrender.com (currently unavailable) 🚨

Architecture

The project follows a clean architecture pattern with the following structure:

weather-api/
├── cmd/
│   └── server/         # Application entry point
├── internal/
│   ├── adapter/        # External service adapters (email, weather API, database)
│   ├── core/           # Domain models and business logic
│   ├── handler/        # HTTP handlers
│   ├── mocks/          # Mock implementations for testing
│   └── util/           # Utility functions and configuration
├── migrations/         # Database migrations
└── web/               # Frontend static files

Key Components

• Weather Service: Fetches weather data from external weather API
• Email Service: Handles email notifications using SMTP
• Subscription Service: Manages user subscriptions and confirmation
• Token Service: Generates subscription tokens
• PostgreSQL Database: Stores subscription information

Prerequisites

• Go 1.24
• PostgreSQL
• SMTP server access (google app generated pass)
• Weather API key (https://www.weatherapi.com)

Environment Variables

Create a .env file in the root directory with the following variables:

DB_CONN_STR=postgres://username:password@localhost:5432/weather_db?sslmode=disable
WEATHER_API_KEY=your_weather_api_key
BASE_URL=http://localhost:8080
SMTP_HOST=smtp.gmail.com
SMTP_PORT=587
SMTP_USER=your_email@gmail.com
SMTP_PASS=your_app_specific_password
PORT=8080

Running the Project

1. Start the server and postgres db using docker:

docker compose up -d

Migrations will be automatically applied upon lift. The server will start on port 8080 by default.

Running Tests

Run all tests:

go test ./...

Run tests only in core/service directory:

go test ./internal/core/service/...

Code Quality with golangci-lint

Install golangci-lint:

go install github.com/golangci/golangci-lint/v2/cmd/golangci-lint@v2.1.6

Run the linter:

golangci-lint run -v

API Endpoints

• GET /api/weather - Get current weather for a city
• POST /api/subscribe - Subscribe to weather updates
• GET /api/confirm/:token - Confirm subscription
• GET /api/unsubscribe/:token - Unsubscribe from updates

Subscription Frequencies

The service supports two types of update frequencies:

1. Hourly Updates: Sent every hour
2. Daily Updates: Sent once daily at 8:00 AM

Please be aware, that after click button Subscribe - on ui only button changes color and email sent, no alerts To modify the update schedule, edit the cron expressions in cmd/server/main.go:

cron.AddFunc("0 * * * *", func() { emailService.SendUpdates(context.Background(), domain.FrequencyHourly) })
cron.AddFunc("0 0 * * *", func() { emailService.SendUpdates(context.Background(), domain.FrequencyDaily) })

Example Subscription Request

{
    "email": "user@example.com",
    "city": "Kyiv",
    "frequency": "hourly"
}