c12s-kubespray/docs/cinder-csi.md

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Cinder CSI Driver
===============
Cinder CSI driver allows you to provision volumes over an OpenStack deployment. The Kubernetes historic in-tree cloud provider is deprecated and will be removed in future versions.
To enable Cinder CSI driver, uncomment the `cinder_csi_enabled` option in `group_vars/all/openstack.yml` and set it to `true`.
To set the number of replicas for the Cinder CSI controller, you can change `cinder_csi_controller_replicas` option in `group_vars/all/openstack.yml`.
You need to source the OpenStack credentials you use to deploy your machines that will host Kubernetes: `source path/to/your/openstack-rc` or `. path/to/your/openstack-rc`.
Make sure the hostnames in your `inventory` file are identical to your instance names in OpenStack. Otherwise [cinder](https://docs.openstack.org/cinder/latest/) won't work as expected.
If you want to deploy the cinder provisioner used with Cinder CSI Driver, you should set `persistent_volumes_enabled` in `group_vars/k8s-cluster/k8s-cluster.yml` to `true`.
You can now run the kubespray playbook (cluster.yml) to deploy Kubernetes over OpenStack with Cinder CSI Driver enabled.
## Usage example ##
To check if Cinder CSI Driver works properly, see first that the cinder-csi pods are running:
```
$ kubectl -n kube-system get pods | grep cinder
csi-cinder-controllerplugin-7f8bf99785-cpb5v 5/5 Running 0 100m
csi-cinder-nodeplugin-rm5x2 2/2 Running 0 100m
```
Check the associated storage class (if you enabled persistent_volumes):
```
$ kubectl get storageclass
NAME PROVISIONER AGE
cinder-csi cinder.csi.openstack.org 100m
```
You can run a PVC and an Nginx Pod using this file `nginx.yaml`:
```
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: csi-pvc-cinderplugin
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1Gi
storageClassName: cinder-csi
---
apiVersion: v1
kind: Pod
metadata:
name: nginx
spec:
containers:
- image: nginx
imagePullPolicy: IfNotPresent
name: nginx
ports:
- containerPort: 80
protocol: TCP
volumeMounts:
- mountPath: /var/lib/www/html
name: csi-data-cinderplugin
volumes:
- name: csi-data-cinderplugin
persistentVolumeClaim:
claimName: csi-pvc-cinderplugin
readOnly: false
```
Apply this conf to your cluster: ```kubectl apply -f nginx.yml```
You should see the PVC provisioned and bound:
```
$ kubectl get pvc
NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE
csi-pvc-cinderplugin Bound pvc-f21ad0a1-5b7b-405e-a462-48da5cb76beb 1Gi RWO cinder-csi 8s
```
And the volume mounted to the Nginx Pod (wait until the Pod is Running):
```
kubectl exec -it nginx -- df -h | grep /var/lib/www/html
/dev/vdb 976M 2.6M 958M 1% /var/lib/www/html
```
## Compatibility with in-tree cloud provider ##
It is not necessary to enable OpenStack as a cloud provider for Cinder CSI Driver to work.
Though, you can run both the in-tree openstack cloud provider and the Cinder CSI Driver at the same time. The storage class provisioners associated to each one of them are differently named.
## Cinder v2 support ##
For the moment, only Cinder v3 is supported by the CSI Driver.
## More info ##
For further information about the Cinder CSI Driver, you can refer to this page: [Cloud Provider OpenStack](https://github.com/kubernetes/cloud-provider-openstack/blob/master/docs/using-cinder-csi-plugin.md).