6.8 KiB
CSI RBD Plugin
The RBD CSI plugin is able to provision new RBD images and attach and mount those to workloads.
Building
CSI RBD 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 rbdplugin. When compiled as an image, it's
stored in the local Docker image store.
Building binary:
make rbdplugin
Building Docker image:
make image-rbdplugin
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 |
--containerized |
true | Whether running in containerized mode |
--metadatastorage |
empty | Whether should metadata be kept on node as file or in a k8s configmap (node or k8s_configmap) |
--configroot |
/etc/csi-config |
Directory in which CSI specific Ceph cluster configurations are present, OR the value k8s_objects if present as kubernetes secrets" |
Available environmental variables:
HOST_ROOTFS: rbdplugin searches /proc directory under the directory set by HOST_ROOTFS.
KUBERNETES_CONFIG_PATH: if you use k8s_configmap as metadata store, specify
the path of your k8s config file (if not specified, the plugin will assume
you're running it inside a k8s cluster and find the config itself).
POD_NAMESPACE: if you use k8s_configmap as metadata store,
POD_NAMESPACE is used to define in which namespace you want
the configmaps to be stored
Available volume parameters:
| Parameter | Required | Description |
|---|---|---|
monitors |
one of monitors, clusterID or monValueFromSecret must be set |
Comma separated list of Ceph monitors (e.g. 192.168.100.1:6789,192.168.100.2:6789,192.168.100.3:6789) |
monValueFromSecret |
one of monitors, clusterID or and monValueFromSecret must be set |
a string pointing the key in the credential secret, whose value is the mon. This is used for the case when the monitors' IP or hostnames are changed, the secret can be updated to pick up the new monitors. |
clusterID |
one of monitors, clusterID or monValueFromSecret must be set |
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 |
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 |
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: If clusterID parameter is used, then an accompanying Ceph cluster
configuration secret or config files needs to be provided to the running pods.
Refer to Cluster ID based configuration
for more information. A suggested way to populate 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
If clusterID is specified, then a secret with various keys and values as
specified in examples/rbd/template-ceph-cluster-ID-secret.yaml needs to be
created, with the secret name matching the string value provided as the
clusterID.
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-attacher-rbac.yaml
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 CSI sidecar containers:
kubectl create -f csi-rbdplugin-attacher.yaml
kubectl create -f csi-rbdplugin-provisioner.yaml
Deploys stateful sets for external-attacher and external-provisioner sidecar containers for CSI RBD.
Deploy RBD CSI driver:
kubectl create -f csi-rbdplugin.yaml
Deploys a daemon set with two containers: CSI 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-attacher-0 1/1 Running 0 23s
pod/csi-rbdplugin-fptqr 2/2 Running 0 21s
pod/csi-rbdplugin-provisioner-0 1/1 Running 0 22s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/csi-rbdplugin-attacher ClusterIP 10.109.15.54 <none> 12345/TCP 26s
service/csi-rbdplugin-provisioner ClusterIP 10.104.2.130 <none> 12345/TCP 23s
...
You can try deploying a demo pod from examples/rbd 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