hcloud-csi-driver

This driver is based on the excellent CSI Driver for DigitalOcean. You can find the original source at https://github.com/digitalocean/csi-digitalocean.

A Container Storage Interface (CSI) Driver for Hetzner Cloud Volumes. The CSI plugin allows you to use Hetzner Cloud Volumes with your preferred Container Orchestrator.

The Hetzner Cloud CSI plugin is mostly tested on Kubernetes. Theoretically it should also work on other Container Orchestrator's, such as Mesos or Cloud Foundry. Feel free to test it on other CO's and give us a feedback.

Releases

The Hetzner Cloud CSI plugin follows semantic versioning. The current version is: v0.0.1. This means that the project is still under active development and may not be production ready. The plugin will continue following the rules below:

• Bug fixes will be released as a PATCH update.
• New features (such as CSI spec bumps) will be released as a MINOR update.
• Significant breaking changes makes a MAJOR update.

Installing to Kubernetes

Requirements:

• Kubernetes v1.10.5 minimum
• --allow-privileged flag must be set to true for both the API server and the kubelet
• (if you use Docker) the Docker daemon of the cluster nodes must allow shared mounts

Rancher users:

Mount Propagation is disabled by default on latest v2.0.6 version of Rancher, which prevents the hcloud-csi-driver to function correctly. To fix the issue temporary, make sure to add the following settings to your cluster configuration YAML file:

services:
  kube-api:
    extra_args:
      feature-gates: MountPropagation=true

  kubelet:
    extra_args:
      feature-gates: MountPropagation=true

1. Create a secret with your Hetzner Cloud API Access Token:

Replace the placeholder string starting with a05... with your own secret and save it as secret.yml:

apiVersion: v1
kind: Secret
metadata:
  name: hcloud
  namespace: kube-system
stringData:
  access-token: "a05dd2f26b9b9ac2asdas__REPLACE_ME____123cb5d1ec17513e06da"

and create the secret using kubectl:

$ kubectl create -f ./secret.yml
secret "hcloud" created

You should now see the hcloud secret in the kube-system namespace along with other secrets

$ kubectl -n kube-system get secrets
NAME                  TYPE                                  DATA      AGE
default-token-jskxx   kubernetes.io/service-account-token   3         18h
hcloud                Opaque                                1         18h

2. Deploy the CSI plugin and sidecars:

Before you continue, be sure to checkout to a tagged release. Always use the latest stable version For example, to use the latest stable version (v0.0.1) you can execute the following command:

$ kubectl apply -f https://raw.githubusercontent.com/apricote/hcloud-csi-driver/master/deploy/kubernetes/releases/hcloud-csi-driver-v0.0.1.yaml

This file will be always updated to point to the latest stable release.

A new storage class will be created with the name hcloud-volumes which is responsible for dynamic provisioning. This is set to "default" for dynamic provisioning. If you're using multiple storage classes you might want to remove the annotation from the csi-storageclass.yaml and re-deploy it. This is based on the recommended mechanism of deploying CSI drivers on Kubernetes

Note that the deployment proposal to Kubernetes is still a work in progress and not all of the written features are implemented. When in doubt, open an issue or ask #sig-storage in Kubernetes Slack

3. Test and verify:

Create a PersistentVolumeClaim. This makes sure a volume is created and provisioned on your behalf:

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: csi-pvc
spec:
  accessModes:
  - ReadWriteOnce
  resources:
    requests:
      storage: 10Gi
  storageClassName: hcloud-volumes

Check that a new PersistentVolume is created based on your claim:

$ kubectl get pv
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS    CLAIM             STORAGECLASS       REASON    AGE
pvc-0879b207-9558-11e8-b6b4-5218f75c62b9   10Gi       RWO            Delete           Bound     default/csi-pvc   hcloud-volumes             3m

The above output means that the CSI plugin successfully created (provisioned) a new Volume on behalf of you. You should be able to see this newly created volume under the Volumes tab in the Hetzner Cloud UI.

The volume is not attached to any node yet. It'll only attached to a node if a workload (i.e: pod) is scheduled to a specific node. Now let us create a Pod that refers to the above volume. When the Pod is created, the volume will be attached, formatted and mounted to the specified Container:

kind: Pod
apiVersion: v1
metadata:
  name: my-csi-app
spec:
  containers:
    - name: my-frontend
      image: busybox
      volumeMounts:
      - mountPath: "/data"
        name: my-do-volume
      command: [ "sleep", "1000000" ]
  volumes:
    - name: my-do-volume
      persistentVolumeClaim:
        claimName: csi-pvc

Check if the pod is running successfully:

$ kubectl describe pods/my-csi-app

Write inside the app container:

$ kubectl exec -ti my-csi-app /bin/sh
/ # touch /data/hello-world
/ # exit
$ kubectl exec -ti my-csi-app /bin/sh
/ # ls /data
hello-world

Development

Requirements:

• Go: min v1.10.x

After making your changes, run the unit tests:

$ make test

If you want to test your changes, create a new image with the version set to dev:

$ VERSION=dev make publish

This will create a binary with version dev and docker image pushed to apricote/hcloud-csi-driver:dev

To run the integration tests run the following:

$ KUBECONFIG=$(pwd)/kubeconfig make test-integration

Release a new version

To release a new version bump first the version:

$ make bump-version

Make sure everything looks good. Create a new branch with all changes:

$ git checkout -b new-release
$ git add .
$ git push origin

After it's merged to master, create a new Github release from master with the version v0.0.1 and then publish a new docker build:

$ git checkout master
$ make publish

This will create a binary with version v0.0.1 and docker image pushed to apricote/hcloud-csi-driver:v0.0.1

Contributing

If you have any issues or would like to contribute, feel free to open an issue/PR