Hetzner Cloud DNS Dynamic Update (multi-zone)

Small Dockerized shell updater for Hetzner DNS (Cloud API).
Supports multiple zones and multiple hosts per zone.

Requirements

• Docker + Docker Compose
• Hetzner Cloud API token with DNS access
• Zones already exist in Hetzner DNS

Quick start

git clone https://github.com/spacecake/hcloud-dyndns.git
cd hcloud-dyndns

cp .env.example .env
# edit .env and set API_TOKEN=...

cp config/hcloud-zones.example.txt config/hcloud-zones.txt
# edit config/hcloud-zones.txt with your zones/hosts (local only)

docker compose up -d --build
docker compose logs -f

If you need a one-shot run, do it without an extra service:

docker compose run --rm -e MODE=once hcloud-dyndns

(Optionally add -e SCRIPT_FLAGS=--quiet.)

Notes:

Hosts are space-separated.

Use FQDNs (recommended).

If you put only the zone on a line, the script updates the zone apex.

config/hcloud-dyndns.conf

Key settings:

Default updates A only

IPV6=1 updates AAAA only

BOTH=1 updates A + AAAA

Environment switches

Set these in docker-compose.yml under environment: (or via docker compose run -e ...).

• AUTO_CREATE=0|1 If 1, missing RRsets will be created automatically (uses add_records).

• TTL=3600 Enforces RRset TTL (default: 3600). Script will change TTL if different.

Update interval

Set in docker-compose.yml:

• INTERVAL=300 (default) = every 5 minutes

Logging

Default behavior: logs only when something changes ([SET] / [UPD] / [TTL]) or on errors ([ERR]).

Enable verbose logs ([OK] too) by adding to docker-compose.yml:

- SCRIPT_FLAGS=--verbose

Errors-only:

- SCRIPT_FLAGS=--quiet

One-shot run (no extra service)

docker compose run --rm -e MODE=once hcloud-dyndns

Example (verbose + auto-create + TTL):

docker compose run --rm -e MODE=once -e SCRIPT_FLAGS=--verbose -e AUTO_CREATE=1 -e TTL=3600 hcloud-dyndns

Update / upgrade

git pull
docker compose up -d --build