ddns6-worker
ddns6-worker is a DynDNS service to update your IPv6 IP adress on Cloudflare hosted domains. It uses the Cloudlfare API to update the dns record. 
Wrangler
Wrangler is used to develop, deploy, and configure your Worker via CLI.
Further documentation for Wrangler can be found here.
Usage
The src/lib.rs file acting as an entrypoint for requests hitting the DynDNS worker.
With wrangler, you can build, test, and deploy your Worker with the following commands:
# run your Worker in an ideal development workflow (with a local server, file watcher & more)
$ wrangler dev --local
# deploy your Worker globally to the Cloudflare network (update your wrangler.toml file for configuration)
$ wrangler deploy
Read the latest worker crate documentation here: https://docs.rs/worker
Configuration
Worker
There are some configuration variables, regarding authentication.
[!CAUTION] The following two variables should be defined as secrets, as they are sensible.
CLOUDFLARE_API_KEY=<your-api-key>
DDNS_SECRET=<your-selfdefined-secret>
The remaining configuration variables are belong to configuration of dns record.
CLOUDFLARE_ZONE_ID=<your-dns-zone-id>
CLOUDLFARE_RECORD_ID=<your-dns-record-id>
CLOUDFLARE_DNS_NAME=<your-record-name (like @, * or specific subdomain)>
DDNS_IP6_TOKEN=<your-ip6-token-to-expose>
Client
On IP change, the client have to send an request to the worker endpoint with the necessary parameters. A request looks like the following:
GET /?secret=<secret>&ip6prefix=<ip6prefix> HTTP/1.1
Host: <worker>
The parameter have to been set as follows:
secret=<your-worker-side-configured-secret>
ip6prefix=<ip6-prefix-of-the-target-network>