Cloudflare DDNS

A tiny Go application that updates Cloudflare DNS records with your current public IPv4 address. This tool is meant for users with dynamic IP addresses who want to keep their domain names pointing to their current location.

It should work right now, but this is still a work in progress

Installation

Option 1: Install via Go (Recommended)

This is the easiest way to install the application. The binary will be automatically downloaded and installed to your Go bin directory.

Prerequisites:

• Go 1.24.5 or higher installed and in your PATH

Installation:

go install github.com/frogfreg/cloudflare-ddns@latest

Running the application:

# The binary will be available in your Go bin directory
cloudflare-ddns

Note: Make sure your Go bin directory is in your PATH. On Unix systems, this is usually ~/go/bin. On Windows, it's typically %GOPATH%\bin or %USERPROFILE%\go\bin.

Option 2: Build from Source

Build the application from source code for your specific platform.

Prerequisites:

• Go 1.24.5 or higher
• Git (to clone the repository)

Build steps:

1. Clone the repository:

   git clone https://github.com/frogfreg/cloudflare-ddns.git
   cd cloudflare-ddns

2. Build the application:

   go build -o cloudflare-ddns main.go

3. Run the application:

   ./cloudflare-ddns

Alternative build options:

• Build with optimizations (smaller binary size):

  go build -ldflags="-s -w" -o cloudflare-ddns main.go

• Build for a different platform (cross-compilation):

  # For Linux
  GOOS=linux GOARCH=amd64 go build -o cloudflare-ddns-linux main.go
  
  # For Windows
  GOOS=windows GOARCH=amd64 go build -o cloudflare-ddns.exe main.go
  
  # For macOS
  GOOS=darwin GOARCH=amd64 go build -o cloudflare-ddns-darwin main.go

Configuration

On first run, the application will create a config.toml file with default values in the directory where the program was executed. You need to update this file with your Cloudflare credentials and domain information.

Required Configuration

Edit the config.toml file and update the following values:

zone-id = "your-zone-id"
dns-record-id = "your-dns-record-id"
cloudflare-email = "your-email@example.com"
cloudflare-api-key = "your-api-key"
domain-name = "your-domain.com"
ttl = 1
type = "A"

Configuration Parameters

Parameter	Description
zone-id	Your Cloudflare Zone ID
dns-record-id	The DNS record ID to update
cloudflare-email	Your Cloudflare account email
cloudflare-api-key	Your Cloudflare API key
domain-name	The domain name to update (e.g., "home.example.com")
ttl	Time to live for the DNS record (in seconds). 1 means automatic
type	DNS record type (currently supports "A" records)

Getting Your Cloudflare Credentials

You can get the required credentials on the Cloudflare dashboard. A domain registered with cloudflare is required.

Usage

Running the Application

./cloudflare-ddns

The application will:

1. Load configuration from config.toml (or create it with default values and exit)
2. Check your current public IP address
3. Compare it with the last known IP (stored in last-ip.txt)
4. Update the Cloudflare DNS record if the IP has changed
5. Continue monitoring every 30 minutes

How It Works

1. IP Detection: The application fetches your current public IP from https://api.ipify.org. This will be configurable in via the config file in the future
2. State Management: It stores the last known IP in last-ip.txt to avoid unnecessary API calls
3. DNS Update: When the IP changes, it updates the specified Cloudflare DNS record via the Cloudflare API
4. Scheduling: The application runs continuously, checking for IP changes every 30 minutes. This should be configurable in the future as well.

Dependencies

• Uses ipify.org for public IP detection
• Built with Viper for configuration management
• Integrates with Cloudflare API

TODO:

• Make this more easily configurable and simple to use