ddclient: add Hetzner DNS provider

[ArcanConsulting]

Add Hetzner DNS providers for ddclient

Summary

Adds native support for Hetzner DNS with both APIs:

• Hetzner DNS - New Cloud API (api.hetzner.cloud) for migrated zones
• Hetzner DNS Legacy - Old API (dns.hetzner.com) for zones not yet migrated

Hetzner is migrating their DNS service from DNS Console to Cloud Console. The old API will be shut down in May 2026.

Features

• Bearer token authentication (Cloud API) / Auth-API-Token (Legacy API)
• Supports A and AAAA records (auto-detected)
• Supports multiple hostnames (comma-separated)
• Supports both zone field and username field for zone name (backwards compatibility)
• Handles FQDN and relative record names
• Configurable TTL

Important: Backend Setting

Users must set the DynDNS backend to native for these providers to work:

1. Go to Services → Dynamic DNS → Settings
2. Set Backend to native
3. Save and apply

The native backend dynamically loads Python-based providers, while the ddclient backend only supports services defined in ddclient itself.

Configuration

Hetzner DNS (new Cloud API)

Field	Value
Service	Hetzner DNS
Zone	Your domain (e.g., example.com)
Password	Hetzner Cloud API token
Hostname(s)	Record(s) to update (e.g., dyn.example.com)

Get your token at Hetzner Cloud Console → Project → Security → API Tokens (Read & Write).

Hetzner DNS Legacy (old API - deprecated)

Field	Value
Service	Hetzner DNS Legacy (deprecated)
Zone	Your domain (e.g., example.com)
Password	Hetzner DNS Console API token
Hostname(s)	Record(s) to update (e.g., dyn.example.com)

Get your token at dns.hetzner.com.

Migration Path

Users with zones still on the old DNS Console should:

1. Use Hetzner DNS Legacy until they migrate
2. Migrate their zone to Cloud Console
3. Create a new Cloud API token
4. Switch to Hetzner DNS

Testing

Tested with:

• Single and multiple hostname updates
• IPv4 (A records)
• Zone lookup by name
• Record creation and updates
• Both Cloud and Legacy APIs

References

• Hetzner Cloud API Documentation
• Hetzner DNS Console API Documentation
• Hetzner DNS Migration Guide