This small Alpine Linux based Docker image will allow you to use the free CloudFlare DNS Service as a Dynamic DNS Provider (DDNS).

This is a multi-arch image and will run on amd64, aarch64, and armhf devices, including the Raspberry Pi.

Image Tag	Architecture	OS	Size
latest	x64	Alpine Linux
armhf	arm32v6	Alpine Linux
aarch64	arm64	Alpine Linux

Quick Setup:

docker run \
  -e API_KEY=xxxxxxx \
  -e ZONE=example.com \
  -e SUBDOMAIN=subdomain \
  oznu/cloudflare-ddns

• --restart=always - ensure the container restarts automatically after host reboot.
• -e API_KEY - Your CloudFlare scoped API token. See the Creating a Cloudflare API token below. Required
• -e ZONE - The DNS zone that DDNS updates should be applied to. Required
• -e SUBDOMAIN - A subdomain of the ZONE to write DNS changes to. If this is not supplied the root zone will be used.
• -e PROXIED - Set to true to make traffic go through the CloudFlare CDN. Defaults to false.
• -e RRTYPE=A - Set to AAAA to use set IPv6 records instead of IPv4 records. Defaults to A for IPv4 records.
• -e DELETE_ON_STOP - Set to true to have the dns record deleted when the container is stopped. Defaults to false.
• -e INTERFACE=tun0 - Set to tun0 to have the IP pulled from a network interface named tun0. If this is not supplied the public IP will be used instead. Requires --network host run argument.

• -e EMAIL - Your CloudFlare email address when using an Account-level token. This variable MUST NOT be set when using a scoped API token.

To create a CloudFlare API token for your DNS zone go to https://dash.cloudflare.com/profile/api-tokens and follow these steps:

1. Click Create Token
2. Provide the token a name, for example, cloudflare-ddns
3. Grant the token the following permissions:
   • Zone - Zone Settings - Read
   • Zone - Zone - Read
   • Zone - DNS - Edit
4. Set the zone resources to:
   • Include - All zones
5. Complete the wizard and copy the generated token into the API_KEY variable for the container

If you need multiple records pointing to your public IP address you can create CNAME records in CloudFlare.

If you're wanting to set IPv6 records set the envrionment variable RRTYPE=AAAA. You will also need to run docker with IPv6 support, or run the container with host networking enabled.

If you prefer to use Docker Compose:

version: '2'
services:
  cloudflare-ddns:
    image: oznu/cloudflare-ddns:latest
    restart: always
    environment:
      - API_KEY=xxxxxxx
      - ZONE=example.com
      - SUBDOMAIN=subdomain
      - PROXIED=false