Support for ipv64.net

[Kritz0]

1. What's the feature? A free ddns service (https://ipv64.net)

2. Extra information? https://ipv64.net/dyndns_helper.php?

[bentemple]

I can look into adding this.
API Docs: https://ipv64.net/dyndns_updater_api
Seems like they have a fully functioning API which allows for querying for current DNS entries etc...

I believe you may be able to use a custom configuration to do this already.
DDNS-Updater config would look something like this, where YOUR_API_KEY is changed to your ipv64.net api key and YOUR_DOMAIN.ipv64.net is changed to your domain name.
NOTE: Change ip_version to ipv6 if you're using ipv6:

{
  "settings": [
    {
      "provider": "custom",
      "domain": "example.ipv64.net",
      "url": "https://ipv64.net/update.php?key=YOUR_API_KEY&domain=example.ipv64.net"
      "ipv4key": "ip",
      "ipv6key": "ip6",
      "success_regex": "success",
      "ip_version": "ipv4"
    }
  ]
}

[qdm12]

@bentemple please go ahead if you feel like it 😉
Also that comment on the custom provider is definitely something I'll re-use for other issues 😄 !

[bentemple]

Heh, just scrolling through the issues trying to triage. Figured a bunch of these could get knocked out with the pre-existing custom feature since most are simple http requests.

I started at the top, but then realized, there are so many domain provider requests, probably makes more sense to start at the oldest and work my way forward prioritizing the ones with the most comments / upvotes.

[qdm12]

Duplicate of #511 so moving essential bits from here to there;
It might be worth investigating a way to easily add these 'dumb ddns' registrars easily in code, for example add a single line to a map[string]string of name to update url, and use the 'custom' provider code 🤔 Something like that would be nice to accelerate resolving requests for registrars. Maybe even a little separate CLI tool cmd/new-provider/main.go to add the new provider to the readme, create a docs/newprovider.md and add it to the Go code where necessary. Anyway, one can dream 😄