Hetzner Cloud Provider

Deploy preview environments to Hetzner Cloud via SSH.

How it works

• Build: SSHs into a fresh Hetzner server, clones the repo, and runs docker build. Docker and Git are installed automatically via cloud-init on first boot.
• Deploy: runs the built Docker image on the same server. Each PR gets its own server.
• Delete: deletes the Hetzner server via the Cloud API.
• List: lists all Hetzner servers with the label previewops=true.

Prerequisites

1. A Hetzner Cloud account and project.
2. An SSH key pair — the public key registered in Hetzner, the private key stored in Previewops secrets.

Step 1 — Create a Hetzner API token

1. Go to your Hetzner Cloud project → Security → API Tokens → Generate API Token.
2. Select Read & Write permission.
3. Store the token as HETZNER_API_TOKEN in Previewops secrets.

Step 2 — Register an SSH key in Hetzner

If you need a new key pair:

ssh-keygen -t ed25519 -C "previewops" -f ~/.ssh/previewops-hetzner

1. Go to your project → Security → SSH Keys → Add SSH Key.
2. Paste the contents of ~/.ssh/previewops-hetzner.pub.
3. Give it a name (e.g. previewops) — this becomes sshKeyName in providerConfig.

Store the private key as HETZNER_SSH_KEY in Previewops secrets:

cat ~/.ssh/previewops-hetzner

Step 3 — Store secrets in Previewops

Step 4 — Configure the repo

provider: hetzner
providerConfig:
  sshKeyName: previewops   # required — name of SSH key registered in Hetzner (step 2)
  serverType: cx22          # optional (default: cx22)
                            # see: hcloud server-type list
  location: nbg1            # optional (default: nbg1)
                            # options: nbg1, fsn1, hel1, ash, hil, sin
  image: ubuntu-24.04       # optional (default: ubuntu-24.04)

Step 5 — Verify

Comment /validate-previewops on any open PR. The bot calls the Hetzner API and confirms the token and SSH key name are valid.

Notes

• Each PR gets its own server (prev-{owner}-{repo}-pr{number}), provisioned on-demand and destroyed on delete/close.
• First deploy takes ~2–3 minutes (server boot + cloud-init Docker installation). Subsequent deploys to the same PR reuse the server and are faster (~30 s).
• The preview URL is http://{server-ipv4}. The container is mapped to port 80 on the host — no port number needed in the URL. For HTTPS, place Caddy or an nginx reverse proxy in front.
• Hetzner pricing is among the lowest of any provider (~€0.005/hr for a cx22).

Troubleshooting