ceph-csi/examples/README.md

# How to test RBD and CephFS plugins with Kubernetes 1.13

Both `rbd` and `cephfs` directories contain `plugin-deploy.sh` and
`plugin-teardown.sh` helper scripts.  You can use those to help you
deploy/teardown RBACs, sidecar containers and the plugin in one go.
By default, they look for the YAML manifests in
`../../deploy/{rbd,cephfs}/kubernetes`.
You can override this path by running `$ ./plugin-deploy.sh /path/to/my/manifests`.

Once the plugin is successfully deployed, you'll need to customize
`storageclass.yaml` and `secret.yaml` manifests to reflect your Ceph cluster
setup.
Please consult the documentation for info about available parameters.

After configuring the secrets, monitors, etc. you can deploy a
testing Pod mounting a RBD image / CephFS volume:

```bash
kubectl create -f secret.yaml
kubectl create -f storageclass.yaml
kubectl create -f pvc.yaml
kubectl create -f pod.yaml
```

Other helper scripts:

* `logs.sh` output of the plugin
* `exec-bash.sh` logs into the plugin's container and runs bash

## How to test RBD Snapshot feature

Before continuing, make sure you enabled the required
feature gate `VolumeSnapshotDataSource=true` in your Kubernetes cluster.

In the `examples/rbd` directory you will find two files related to snapshots:
[snapshotclass.yaml](./rbd/snapshotclass.yaml) and
[snapshot.yaml](./rbd/snapshot.yaml).

Once you created your RBD volume, you'll need to customize at least
`snapshotclass.yaml` and make sure the `monitors` and `pool` parameters match
your Ceph cluster setup.
If you followed the documentation to create the rbdplugin, you shouldn't
have to edit any other file.

After configuring everything you needed, deploy the snapshot class:

```bash
kubectl create -f snapshotclass.yaml
```

Verify that the snapshot class was created:

```console
$ kubectl get volumesnapshotclass
NAME                      AGE
csi-rbdplugin-snapclass   4s
```

Create a snapshot from the existing PVC:

```bash
kubectl create -f snapshot.yaml
```

To verify if your volume snapshot has successfully been created, run the following:

```console
$ kubectl get volumesnapshot
NAME               AGE
rbd-pvc-snapshot   6s
```

To check the status of the snapshot, run the following:

```bash
$ kubectl describe volumesnapshot rbd-pvc-snapshot

Name:         rbd-pvc-snapshot
Namespace:    default
Labels:       <none>
Annotations:  <none>
API Version:  snapshot.storage.k8s.io/v1alpha1
Kind:         VolumeSnapshot
Metadata:
  Creation Timestamp:  2019-02-06T08:52:34Z
  Finalizers:
    snapshot.storage.kubernetes.io/volumesnapshot-protection
  Generation:        5
  Resource Version:  84239
  Self Link:         /apis/snapshot.storage.k8s.io/v1alpha1/namespaces/default/volumesnapshots/rbd-pvc-snapshot
  UID:               8b9b5740-29ec-11e9-8e0f-b8ca3aad030b
Spec:
  Snapshot Class Name:    csi-rbdplugin-snapclass
  Snapshot Content Name:  snapcontent-8b9b5740-29ec-11e9-8e0f-b8ca3aad030b
  Source:
    API Group:  <nil>
    Kind:       PersistentVolumeClaim
    Name:       rbd-pvc
Status:
  Creation Time:  2019-02-06T08:52:34Z
  Ready To Use:   true
  Restore Size:   1Gi
Events:           <none>
```

To be sure everything is OK you can run `rbd snap ls [your-pvc-name]` inside
one of your Ceph pod.

To restore the snapshot to a new PVC, deploy
[pvc-restore.yaml](./rbd/pvc-restore.yaml) and a testing pod
[pod-restore.yaml](./rbd/pvc-restore.yaml):

```bash
kubectl create -f pvc-restore.yaml
kubectl create -f pod-restore.yaml
```

## How to enable multi node attach support for RBD

*WARNING*  This feature is strictly for workloads that know how to deal
with concurrent acces to the Volume (eg Active/Passive applications).
Using RWX modes on non clustered file systems with applications trying
to simultaneously access the Volume will likely result in data corruption!

### Example process to test the multiNodeWritable feature

Modify your current storage class, or create a new storage class specifically
for multi node writers by adding the `multiNodeWritable: "enabled"` entry to
your parameters.  Here's an example:

```
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
   name: csi-rbd
provisioner: csi-rbdplugin
parameters:
    monitors: rook-ceph-mon-b.rook-ceph.svc.cluster.local:6789
    pool: rbd
    imageFormat: "2"
    imageFeatures: layering
    csiProvisionerSecretName: csi-rbd-secret
    csiProvisionerSecretNamespace: default
    csiNodePublishSecretName: csi-rbd-secret
    csiNodePublishSecretNamespace: default
    adminid: admin
    userid: admin
    fsType: xfs
    multiNodeWritable: "enabled"
reclaimPolicy: Delete
```

Now, you can request Claims from the configured storage class that include
the `ReadWriteMany` access mode:

```
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: pvc-1
spec:
  accessModes:
  - ReadWriteMany
  resources:
    requests:
      storage: 1Gi
  storageClassName: csi-rbd
```

Create a POD that uses this PVC:

```
apiVersion: v1
kind: Pod
metadata:
  name: test-1
spec:
  containers:
   - name: web-server
     image: nginx
     volumeMounts:
       - name: mypvc
         mountPath: /var/lib/www/html
  volumes:
   - name: mypvc
     persistentVolumeClaim:
       claimName: pvc-1
       readOnly: false
```

Wait for the POD to enter Running state, write some data to
`/var/lib/www/html`

Now, we can create a second POD (ensure the POD is scheduled on a different
node; multiwriter single node works without this feature) that also uses this
PVC at the same time

```
apiVersion: v1
kind: Pod
metadata:
  name: test-2
spec:
  containers:
   - name: web-server
     image: nginx
     volumeMounts:
       - name: mypvc
         mountPath: /var/lib/www/html
  volumes:
   - name: mypvc
     persistentVolumeClaim:
       claimName: pvc-1
       readOnly: false
```

If you access the pod you can check that your data is avaialable at
`/var/lib/www/html`

## Testing Raw Block feature in kubernetes with RBD volumes

CSI block volume support is feature-gated and turned off by default. To run CSI
with block volume support enabled, a cluster administrator must enable the
feature for each Kubernetes component using the following feature gate flags:

--feature-gates=BlockVolume=true,CSIBlockVolume=true

these feature-gates must be enabled on both api-server and kubelet

### create a raw-block PVC

```yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: raw-block-pvc
spec:
  accessModes:
    - ReadWriteOnce
  volumeMode: Block
  resources:
    requests:
      storage: 1Gi
  storageClassName: csi-rbd
```

create raw block pvc

```console
kubectl create -f raw-block-pvc.yaml
```

### create a pod to mount raw-block PVC

```yaml
---
apiVersion: v1
kind: Pod
metadata:
  name: pod-with-raw-block-volume
spec:
  containers:
    - name: fc-container
      image: fedora:26
      command: ["/bin/sh", "-c"]
      args: [ "tail -f /dev/null" ]
      volumeDevices:
        - name: data
          devicePath: /dev/xvda
  volumes:
    - name: data
      persistentVolumeClaim:
        claimName: raw-block-pvc
```

Create a POD that uses raw block PVC

```console
kubectl create -f raw-block-pod.yaml
```