Moon Rise and Set Times

A web application that calculates and displays moon rise and set times for any location on Earth using Google Maps integration.

Features

• Interactive Google Maps interface for location selection
• Automatic geolocation detection
• Smart timezone selector with auto-detection and 50+ timezones
• Real-time moon rise and set calculations
• Full month calendar view with sun and moon times

Technology Stack

• Backend: Go 1.21+
• Frontend: Vanilla JavaScript, jQuery 3.7.1
• Maps: Google Maps JavaScript API with AdvancedMarkerElement
• Calculations: riseset library

Local Development

1. Clone the repository

   git clone https://github.com/exploded/moon.git
   cd moon

2. Install dependencies

   go mod download

3. Set up environment variables Use .env.example to create your own .env file

   GOOGLE_MAPS_API_KEY=your_actual_api_key_here
   PROD=False
   PORT=8484

4. Get a Google Maps API Key

   • Go to Google Cloud Console
   • Create a new project or select existing one
   • Enable "Maps JavaScript API"
   • Create credentials (API Key)
   • IMPORTANT: Restrict the API key (recommended for production):
     • Application restrictions: Set HTTP referrers
       • Add your domain: https://yourdomain.com/*
       • For local development: http://localhost:8484/*
     • API restrictions: Restrict key to "Maps JavaScript API" only
     • Set usage quotas to prevent abuse

   Security Note: Google Maps JavaScript API keys are client-side visible by design. The security comes from properly configuring API key restrictions in Google Cloud Console, not from hiding the key.

Windows Development

build.bat

Or for quick restart (when already built):

run.bat

Cross-Compilation (Building for Linux from Windows)

Build for Debian/Ubuntu (amd64):

set GOOS=linux
set GOARCH=amd64
go build -o moon

Build for Windows (local):

set GOOS=windows
set GOARCH=amd64
go build -o moon.exe

Testing

go test -v
go test -cover

Deployment

GitHub repository secrets

Settings → Secrets and variables → Actions → New repository secret

Secret name	Value
DEPLOY_HOST	Your Linode public IP or hostname
DEPLOY_USER	deploy
DEPLOY_SSH_KEY	The private key printed by the setup script
DEPLOY_PORT	Your SSH port (only if not port 22)

Triggering a deployment

git push origin master

View deployment logs at https://github.com/exploded/moon/actions

Configuration

Environment Variables

Variable	Required	Default	Description
GOOGLE_MAPS_API_KEY	Yes	—	Your Google Maps API key
PROD	No	False	Set to True for production mode
PORT	No	8484	Port the server listens on

Server Settings

• Port: 8484 (default)
• Read Timeout: 5 seconds
• Write Timeout: 5 seconds
• Idle Timeout: 120 seconds
• Shutdown Grace Period: 5 seconds

Security Features

• X-Content-Type-Options, X-Frame-Options, X-XSS-Protection headers
• Referrer-Policy: strict-origin-when-cross-origin
• Content-Security-Policy with strict resource restrictions
• Input validation for latitude, longitude, and timezone
• Graceful shutdown on SIGTERM/SIGINT
• API key injected via server-side template rendering (not exposed via endpoint)

License

Copyright 2020–2026 James McHugh

Licensed under the Apache License, Version 2.0. See LICENSE.

Credits

• Moon rise/set algorithm by Keith Burnett
• Background image: NASA/Goddard Space Flight Center Scientific Visualization
• Map integration: Google Maps JavaScript API