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Add doc for Hetzner
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1 change: 1 addition & 0 deletions README.md
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Expand Up @@ -122,6 +122,7 @@ The following tutorials are provided:
* [Cloudflare](docs/tutorials/cloudflare.md)
* [CoreDNS](docs/tutorials/coredns.md)
* [DigitalOcean](docs/tutorials/digitalocean.md)
* [Hetzner](docs/tutorials/hetzner.md)
* [DNSimple](docs/tutorials/dnsimple.md)
* [Dyn](docs/tutorials/dyn.md)
* [Exoscale](docs/tutorials/exoscale.md)
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191 changes: 191 additions & 0 deletions docs/tutorials/hetzner.md
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# Setting up ExternalDNS for Services on Hetzner DNS

This tutorial describes how to setup ExternalDNS for usage within a Kubernetes cluster using Hetzner DNS.

Make sure to use **>=0.7.2** version of ExternalDNS for this tutorial.

## Creating a Hetzner DNS zone

If you want to learn about how to use Hetzner's DNS service read the following tutorial series:

[An Introduction to Managing DNS](https://wiki.hetzner.de/index.php/DNS_Overview), and [Add a new DNS zone](https://wiki.hetzner.de/index.php/Getting_started).

Create a new DNS zone where you want to create your records in. Let's use `example.com` as an example here.

## Creating Hetzner Credentials

Generate a new personal token by going to [the API settings](https://dns.hetzner.com/settings/api-token) or follow [Generating an API access token](https://wiki.hetzner.de/index.php/API_access_token) if you need more information. Give the token a name and choose read and write access. The token needs to be passed to ExternalDNS so make a note of it for later use.

The environment variable `HETZNER_TOKEN` will be needed to run ExternalDNS with Hetzner.

## Deploy ExternalDNS

Connect your `kubectl` client to the cluster you want to test ExternalDNS with.
Then apply one of the following manifests file to deploy ExternalDNS.

### Manifest (for clusters without RBAC enabled)
```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: external-dns
spec:
replicas: 1
selector:
matchLabels:
app: external-dns
strategy:
type: Recreate
template:
metadata:
labels:
app: external-dns
spec:
containers:
- name: external-dns
image: registry.opensource.zalan.do/teapot/external-dns:latest
args:
- --source=service # ingress is also possible
- --domain-filter=example.com # (optional) limit to only example.com domains; change to match the zone created above.
- --provider=hetznerYOUR_HETZNER_DNS_API_KEY
env:
- name: HETZNER_TOKEN
value: "YOUR_HETZNER_DNS_API_KEY"
```

### Manifest (for clusters with RBAC enabled)
```yaml
apiVersion: v1
kind: ServiceAccount
metadata:
name: external-dns
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
name: external-dns
rules:
- apiGroups: [""]
resources: ["services","endpoints","pods"]
verbs: ["get","watch","list"]
- apiGroups: ["extensions"]
resources: ["ingresses"]
verbs: ["get","watch","list"]
- apiGroups: [""]
resources: ["nodes"]
verbs: ["list"]
---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRoleBinding
metadata:
name: external-dns-viewer
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: external-dns
subjects:
- kind: ServiceAccount
name: external-dns
namespace: default
---
apiVersion: apps/v1
kind: Deployment
metadata:
name: external-dns
spec:
replicas: 1
selector:
matchLabels:
app: external-dns
strategy:
type: Recreate
template:
metadata:
labels:
app: external-dns
spec:
serviceAccountName: external-dns
containers:
- name: external-dns
image: registry.opensource.zalan.do/teapot/external-dns:latest
args:
- --source=service # ingress is also possible
- --domain-filter=example.com # (optional) limit to only example.com domains; change to match the zone created above.
- --provider=hetzner
env:
- name: HETZNER_TOKEN
value: "YOUR_HETZNER_DNS_API_KEY"
```


## Deploying an Nginx Service

Create a service file called 'nginx.yaml' with the following contents:

```yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx
spec:
replicas: 1
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- image: nginx
name: nginx
ports:
- containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
name: nginx
annotations:
external-dns.alpha.kubernetes.io/hostname: my-app.example.com
spec:
selector:
app: nginx
type: LoadBalancer
ports:
- protocol: TCP
port: 80
targetPort: 80
```

Note the annotation on the service; use the same hostname as the Hetzner DNS zone created above.

ExternalDNS uses this annotation to determine what services should be registered with DNS. Removing the annotation will cause ExternalDNS to remove the corresponding DNS records.

Create the deployment and service:

```console
$ kubectl create -f nginx.yaml
```

Depending where you run your service it can take a little while for your cloud provider to create an external IP for the service.

Once the service has an external IP assigned, ExternalDNS will notice the new service IP address and synchronize the Hetzner DNS records.

## Verifying Hetzner DNS records

Check your [Hetzner DNS UI](https://dns.hetzner.com/) to view the records for your Hetzner DNS zone.

Click on the zone for the one created above if a different domain was used.

This should show the external IP address of the service as the A record for your domain.

## Cleanup

Now that we have verified that ExternalDNS will automatically manage Hetzner DNS records, we can delete the tutorial's example:

```
$ kubectl delete service -f nginx.yaml
$ kubectl delete service -f externaldns.yaml
```

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