ceph-csi/docs/deploy-rbd.md

CSI RBD Plugin

The RBD CSI plugin is able to provision new RBD images and attach and mount those to workloads.

Building

CSI plugin can be compiled in a form of a binary file or in a form of a Docker image. When compiled as a binary file, the result is stored in _output/ directory with the name cephcsi. When compiled as an image, it's stored in the local Docker image store with name cephcsi.

Building binary:

make cephcsi

Building Docker image:

make image-cephcsi

Configuration

Available command line arguments:

Option	Default value	Description
--endpoint	unix://tmp/csi.sock	CSI endpoint, must be a UNIX socket
--drivername	rbd.csi.ceph.com	name of the driver (Kubernetes: provisioner field in StorageClass must correspond to this value)
--nodeid	empty	This node's ID
--type	empty	driver type `[rbd
--containerized	true	Whether running in containerized mode
--instanceid	"default"	Unique ID distinguishing this instance of Ceph CSI among other instances, when sharing Ceph clusters across CSI instances for provisioning

Available environmental variables:

HOST_ROOTFS: rbdplugin searches /proc directory under the directory set by HOST_ROOTFS.

Available volume parameters:

Parameter	Required	Description
clusterID	yes	String representing a Ceph cluster, must be unique across all Ceph clusters in use for provisioning, cannot be greater than 36 bytes in length, and should remain immutable for the lifetime of the Ceph cluster in use
pool	yes	Ceph pool into which the RBD image shall be created
imageFormat	no	RBD image format. Defaults to 2. See man pages
imageFeatures	no	RBD image features. Available for imageFormat=2. CSI RBD currently supports only layering feature. See man pages
csi.storage.k8s.io/provisioner-secret-name, csi.storage.k8s.io/node-publish-secret-name	yes (for Kubernetes)	name of the Kubernetes Secret object containing Ceph client credentials. Both parameters should have the same value
csi.storage.k8s.io/provisioner-secret-namespace, csi.storage.k8s.io/node-publish-secret-namespace	yes (for Kubernetes)	namespaces of the above Secret objects
mounter	no	if set to rbd-nbd, use rbd-nbd on nodes that have rbd-nbd and nbd kernel modules to map rbd images

NOTE: An accompanying CSI configuration file, needs to be provided to the running pods. Refer to Creating CSI configuration for more information.

NOTE: A suggested way to populate and retain uniqueness of the clusterID is to use the output of ceph fsid of the Ceph cluster to be used for provisioning.

Required secrets:

Admin credentials are required for provisioning new RBD images ADMIN_NAME: ADMIN_PASSWORD - note that the key of the key-value pair is the name of the client with admin privileges, and the value is its password

Deployment with Kubernetes

Requires Kubernetes 1.11

Your Kubernetes cluster must allow privileged pods (i.e. --allow-privileged flag must be set to true for both the API server and the kubelet). Moreover, as stated in the mount propagation docs, the Docker daemon of the cluster nodes must allow shared mounts.

YAML manifests are located in deploy/rbd/kubernetes.

Deploy RBACs for sidecar containers and node plugins:

kubectl create -f csi-provisioner-rbac.yaml
kubectl create -f csi-nodeplugin-rbac.yaml

Those manifests deploy service accounts, cluster roles and cluster role bindings. These are shared for both RBD and CephFS CSI plugins, as they require the same permissions.

Deploy ConfigMap for CSI plugins:

kubectl create -f csi-config-map.yaml

The config map deploys an empty CSI configuration that is mounted as a volume within the Ceph CSI plugin pods. To add a specific Ceph clusters configuration details, refer to Creating CSI configuration for RBD based provisioning for more information.

Deploy CSI sidecar containers:

kubectl create -f csi-rbdplugin-provisioner.yaml

Deploys stateful set of provision which includes external-provisioner ,external-attacher,csi-snapshotter sidecar containers and CSI RBD plugin.

Deploy RBD CSI driver:

kubectl create -f csi-rbdplugin.yaml

Deploys a daemon set with two containers: CSI node-driver-registrar and the CSI RBD driver.

Verifying the deployment in Kubernetes

After successfully completing the steps above, you should see output similar to this:

$ kubectl get all
NAME                              READY     STATUS    RESTARTS   AGE
pod/csi-rbdplugin-fptqr           2/2       Running   0          21s
pod/csi-rbdplugin-provisioner-0   4/4       Running   0          22s

NAME                                TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)     AGE
service/csi-rbdplugin-provisioner   ClusterIP   10.104.2.130   <none>        12345/TCP   23s
...

Once the CSI plugin configuration is updated with details from a Ceph cluster of choice, you can try deploying a demo pod from examples/rbd using the instructions provided to test the deployment further.

Deployment with Helm

The same requirements from the Kubernetes section apply here, i.e. Kubernetes version, privileged flag and shared mounts.

The Helm chart is located in deploy/rbd/helm.

Deploy Helm Chart:

helm install ./deploy/rbd/helm

The Helm chart deploys all of the required resources to use the CSI RBD driver. After deploying the chart you can verify the deployment using the instructions above for verifying the deployment with Kubernetes