Cloudflare Dynamic DNS

A Simple Python based application that updates a Cloudflare DNS A record entry with a host's public IPv4 address.

The application polls Cloudflare's cdn-cgi/trace data every 15 minutes to determine the host's public IPv4 address. On start up and on a change of the hosts IPv4 address, the application will update Cloudflare DNS A record for the provided domain.

Deploy with Docker Compose

Pre-built images are available via the GitHub Container Repository: ghcr.io/lucace/cloudflare-ddns

Configuring the Docker Image

Copy and modify the docker-compose.yml file, setting the following environment variables:

Variable	Type	Required	Default	Description
CLOUDFLARE_API_KEY	String	Yes	None	Cloudflare API Key
CLOUDFLARE_ZONE_ID	String	Yes	None	Cloudflare DNS Entry Zone ID
DOMAIN_NAME	String	Yes	None	Domain Name to Manage
VERBOSE	Boolean	No	False	Enable Verbose Messages
DOMAIN_TTL	Integer	No	3600	DNS Record Time to Live in Seconds
UPDATE_RATE	Integer	No	900	Polling Update Rate in Seconds

Important

"{{ CLOUDFLARE_API_KEY }}", "{{ CLOUDFLARE_ZONE_ID }}", and "{{ DOMAIN NAME }}" in the docker-compose.yml file example are placeholders and must be replaced with actual values.

services:
  cloudflare-ddns:
    container_name: cloudflare-ddns
    image: ghcr.io/lucace/cloudflare-ddns:latest
    environment:
      VERBOSE: True
      CLOUDFLARE_API_KEY: {{ CLOUDFLARE_API_KEY }}
      CLOUDFLARE_ZONE_ID: {{ CLOUDFLARE_ZONE_ID }}
      DOMAIN_NAME: {{ DOMAIN NAME }}
      DOMAIN_TTL: 3600
      UPDATE_RATE: 900
    restart: unless-stopped
    read_only: True
    cap_drop: [all]
    security_opt: [no-new-privileges:true]

Running the Docker Image

From the directory containing docker-compose.yml, start the container:

docker compose up -d

Cloudflare

This application requires a Cloudflare API Key and a Zone ID to update the DNS entry for a domain.

Cloudflare API Key

A Cloudflare API Key with DNS editing permissions is required. The API key should only include the specific zone (doman name) that will be updated. Instructions on how to create an API Key can be found on Cloudflare's developer documentation site:

https://developers.cloudflare.com/fundamentals/api/get-started/create-token/

Cloudflare Zone ID

A Cloudflare Zone ID is a unique identifier Cloudflare assigns to each domain (called a zone) in your Cloudflare account. The Zone ID for the domain name record that will be updated is required and can be found in the Cloudflare web interface. Instructions on how to determine what the Zone ID is for a domain can be found on Cloudflare's developer documentation site:

https://developers.cloudflare.com/fundamentals/concepts/accounts-and-zones/
https://developers.cloudflare.com/fundamentals/account/find-account-and-zone-ids/