ACME webhook for Hetzner DNS API

This solver can be used when you want to use cert-manager with Hetzner DNS API. API documentation is here

Requirements

• go >= 1.13.0
• helm >= v3.0.0
• kubernetes >= v1.14.0
• cert-manager >= 0.12.0

Installation

cert-manager

Follow the instructions using the cert-manager documentation to install it within your cluster.

Webhook

Using public helm chart

helm repo add cert-manager-webhook-hetzner https://vadimkim.github.io/cert-manager-webhook-hetzner
# Replace the groupName value with your desired domain
helm install --namespace cert-manager cert-manager-webhook-hetzner cert-manager-webhook-hetzner/cert-manager-webhook-hetzner --set groupName=acme.yourdomain.tld

From local checkout

helm install --namespace cert-manager cert-manager-webhook-hetzner deploy/cert-manager-webhook-hetzner

Note: The kubernetes resources used to install the Webhook should be deployed within the same namespace as the cert-manager.

To uninstall the webhook run

helm uninstall --namespace cert-manager cert-manager-webhook-hetzner

Issuer

Create a ClusterIssuer or Issuer resource as following: (Keep in Mind that the Example uses the Staging URL from Let's Encrypt. Look at Getting Start for using the normal Let's Encrypt URL.)

apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  name: letsencrypt-staging
spec:
  acme:
    # The ACME server URL
    server: https://acme-staging-v02.api.letsencrypt.org/directory

    # Email address used for ACME registration
    email: [email protected] # REPLACE THIS WITH YOUR EMAIL!!!

    # Name of a secret used to store the ACME account private key
    privateKeySecretRef:
      name: letsencrypt-staging

    solvers:
      - dns01:
          webhook:
            # This group needs to be configured when installing the helm package, otherwise the webhook won't have permission to create an ACME challenge for this API group.
            groupName: acme.yourdomain.tld
            solverName: hetzner
            config:
              secretName: hetzner-secret
              zoneName: example.com # (Optional): When not provided the Zone will searched in Hetzner API by recursion on full domain name
              apiUrl: https://dns.hetzner.com/api/v1

Credentials

In order to access the Hetzner API, the webhook needs an API token.

If you choose another name for the secret than hetzner-secret, you must install the chart with a modified secretName value. Policies ensure that no other secrets can be read by the webhook. Also modify the value of secretName in the [Cluster]Issuer.

The secret for the example above will look like this:

apiVersion: v1
kind: Secret
metadata:
  name: hetzner-secret
  namespace: cert-manager
type: Opaque
data:
  api-key: your-key-base64-encoded

Create a certificate

Finally you can create certificates, for example:

apiVersion: cert-manager.io/v1
kind: Certificate
metadata:
  name: example-cert
  namespace: cert-manager
spec:
  commonName: example.com
  dnsNames:
    - example.com
  issuerRef:
    name: letsencrypt-staging
    kind: ClusterIssuer
  secretName: example-cert

Development

Running the test suite

All DNS providers must run the DNS01 provider conformance testing suite, else they will have undetermined behaviour when used with cert-manager.

It is essential that you configure and run the test suite when creating a DNS01 webhook.

First, you need to have Hetzner account with access to DNS control panel. You need to create API token and have a registered and verified DNS zone there. Then you need to replace zoneName parameter at testdata/hetzner/config.json file with actual one. You also must encode your api token into base64 and put the hash into testdata/hetzner/hetzner-secret.yml file.

You can then run the test suite with:

# first install necessary binaries (only required once)
./scripts/fetch-test-binaries.sh
# then run the tests
TEST_ZONE_NAME=example.com. make verify

Creating new package

To build new Docker image for multiple architectures and push it to hub:

docker buildx build --platform linux/amd64,linux/arm64,linux/arm/v7 -t zmejg/cert-manager-webhook-hetzner:1.2.0 . --push

To compile and publish new Helm chart version:

helm package deploy/cert-manager-webhook-hetzner
git checkout gh-pages
helm repo index . --url https://vadimkim.github.io/cert-manager-webhook-hetzner/