Container Storage Interface driver for Hetzner Cloud

This is a Container Storage Interface driver for Hetzner Cloud enabling you to use ReadWriteOnce Volumes within Kubernetes. Please note that this driver requires Kubernetes 1.13 or newer.

Getting Started

Create an API token in the Hetzner Cloud Console.

Create a secret containing the token:

# secret.yml
apiVersion: v1
kind: Secret
metadata:
  name: hcloud
  namespace: kube-system
stringData:
  token: YOURTOKEN

and apply it:

kubectl apply -f <secret.yml>

Deploy the CSI driver and wait until everything is up and running:

Have a look at our Version Matrix to pick the correct deployment file.
```
kubectl apply -f https://raw.githubusercontent.com/hetznercloud/csi-driver/v1.5.1/deploy/kubernetes/hcloud-csi.yml
```

To verify everything is working, create a persistent volume claim and a pod which uses that volume:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: csi-pvc
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 10Gi
  storageClassName: hcloud-volumes
---
kind: Pod
apiVersion: v1
metadata:
  name: my-csi-app
spec:
  containers:
    - name: my-frontend
      image: busybox
      volumeMounts:
      - mountPath: "/data"
        name: my-csi-volume
      command: [ "sleep", "1000000" ]
  volumes:
    - name: my-csi-volume
      persistentVolumeClaim:
        claimName: csi-pvc

Once the pod is ready, exec a shell and check that your volume is mounted at /data.

kubectl exec -it my-csi-app -- /bin/sh

Integration with Root Servers

Root servers can be part of the cluster, but the CSI plugin doesn't work there. Taint the root server as follows to skip that node for the daemonset.

kubectl label nodes <node name> instance.hetzner.cloud/is-root-server=true

Versioning policy

We aim to support the latest three versions of Kubernetes. After a new Kubernetes version has been released we will stop supporting the oldest previously supported version. This does not necessarily mean that the CSI driver does not still work with this version. However, it means that we do not test that version anymore. Additionally, we will not fix bugs related only to an unsupported version.

Kubernetes	CSI Driver	Deployment File
1.22	1.6.0, master	https://raw.githubusercontent.com/hetznercloud/csi-driver/v1.6.0/deploy/kubernetes/hcloud-csi.yml
1.21	1.6.0, master	https://raw.githubusercontent.com/hetznercloud/csi-driver/v1.6.0/deploy/kubernetes/hcloud-csi.yml
1.20	1.6.0, master	https://raw.githubusercontent.com/hetznercloud/csi-driver/v1.6.0/deploy/kubernetes/hcloud-csi.yml

E2E Tests

The Hetzner Cloud CSI Driver was tested against the official k8s e2e tests for a specific version. You can run the tests with the following commands. Keep in mind, that these tests run on real cloud servers and will create volumes that will be billed.

Test Server Setup:

1x CPX21 (Ubuntu 18.04)

Requirements: Docker and Go 1.17

Configure your environment correctly

export HCLOUD_TOKEN=<specifiy a project token>
export K8S_VERSION=1.21.0 # The specific (latest) version is needed here
export USE_SSH_KEYS=key1,key2 # Name or IDs of your SSH Keys within the Hetzner Cloud, the servers will be accessable with that keys

Run the tests

go test $(go list ./... | grep e2etests) -v -timeout 60m

The tests will now run, this will take a while (~30 min).

If the tests fail, make sure to clean up the project with the Hetzner Cloud Console or the hcloud cli.

License