AutoDNS

Small Flask service that updates a Cloudflare A record to the caller's IP. A client hits /update-dns?guid=<GUID>, AutoDNS looks up the record mapped to that GUID, and sets its content to the client IP. Optional Apprise notifications.

Quick Start

Requires Docker and a Cloudflare API token with DNS edit permission on the zone. The A record must already exist; AutoDNS updates records but does not create them.

docker run -d \
  --name autodns \
  --restart unless-stopped \
  -p 4295:4295 \
  -v /your/path/to/config:/config \
  -e CF_ZONE_ID="your-zone-id" \
  -e CF_API_TOKEN="your-api-token" \
  -e AUTODNS_PORT=4295 \
  ghcr.io/baker-scripts/autodns:develop

docker-compose.example.yml has the same setup for Compose.

Create a GUID for a record (the full record name, for example home.example.com):

docker exec autodns python autodns.py generate home.example.com

The GUID is the SHA-256 hash of the name, so anyone who knows the name can compute it. Treat the GUID as an identifier, not a secret, and keep the endpoint behind access controls.

Mappings are stored in /config/guid_mapping.json, so mount /config to keep them.

Configuration

All settings are environment variables.

Variable	Default	Description
CF_ZONE_ID	none	Cloudflare zone ID that holds the records.
CF_API_TOKEN	none	Cloudflare API token.
AUTODNS_PORT	5000	Port the server listens on. The Docker image exposes 4295, so set AUTODNS_PORT=4295 to match.
AUTODNS_HOST	0.0.0.0	Address the server binds to.
ENABLE_NOTIFICATIONS	false	Set to true, 1, or t to send notifications.
APPRISE_URLS	empty	Comma-separated Apprise URLs. Used only when notifications are enabled.
TRUSTED_PROXIES	empty	Comma-separated proxy IPs. X-Forwarded-For is trusted only when the direct connection comes from one of these. When empty, the connection's remote address is always used.

Usage

curl "http://localhost:4295/update-dns?guid=<GUID>"

The record is set to the client IP. Run it from cron or a scheduler on the host whose IP you want to publish.

Status	Meaning
200	Record updated.
400	guid parameter missing.
404	Record does not exist in Cloudflare, or the Cloudflare API returned an error.
429	Unknown GUID, or the record was updated in the last 10 minutes.
500	Cloudflare rejected the update.

CLI commands:

Command	Description
python autodns.py	Start the server.
python autodns.py generate <name>	Create a GUID for a record name and save it to the mapping file.

For local development, run pip install -r requirements.txt and then python autodns.py. The mapping file path is fixed at /config/guid_mapping.json.

Contributing

Issues and pull requests welcome. See the contributing guidelines. The default branch is develop.

Disclaimer

This software is provided as-is with no warranty. Test in a non-production zone first. The authors are not responsible for DNS issues or service disruptions.

License

GPL-3.0