8.2 KiB
CSI CephFS plugin
The CSI CephFS plugin is able to both provision new CephFS volumes and attach and mount existing ones to workloads.
Building
CSI CephFS plugin can be compiled in the form of a binary file or in the form
of a Docker image.
When compiled as a binary file, the result is stored in _output/
directory with the name cephfsplugin
.
When compiled as an image, it's stored in the local Docker image store.
Building binary:
make cephfsplugin
Building Docker image:
make image-cephfsplugin
Configuration
Available command line arguments:
Option | Default value | Description |
---|---|---|
--endpoint |
unix://tmp/csi.sock |
CSI endpoint, must be a UNIX socket |
--drivername |
cephfs.csi.ceph.com |
name of the driver (Kubernetes: provisioner field in StorageClass must correspond to this value) |
--nodeid |
empty | This node's ID |
--volumemounter |
empty | default volume mounter. Available options are kernel and fuse . This is the mount method used if volume parameters don't specify otherwise. If left unspecified, the driver will first probe for ceph-fuse in system's path and will choose Ceph kernel client if probing failed. |
--metadatastorage |
empty | Whether metadata should be kept on node as file or in a k8s configmap (node or k8s_configmap ) |
--mountcachedir |
empty | volume mount cache info save dir. If left unspecified, the dirver will not record mount info, or it will save mount info and when driver restart it will remount volume it cached. |
Available environmental variables:
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 |
yes | 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 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. If both monitors and monValueFromSecret are set and the monitors set in the secret exists, monValueFromSecret takes precedence. |
mounter |
no | Mount method to be used for this volume. Available options are kernel for Ceph kernel client and fuse for Ceph FUSE driver. Defaults to "default mounter", see command line arguments. |
provisionVolume |
yes | Mode of operation. BOOL value. If true , a new CephFS volume will be provisioned. If false , an existing volume will be used. |
pool |
for provisionVolume=true |
Ceph pool into which the volume shall be created |
rootPath |
for provisionVolume=false |
Root path of an existing CephFS volume |
csi.storage.k8s.io/provisioner-secret-name , csi.storage.k8s.io/node-stage-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-stage-secret-namespace |
for Kubernetes | namespaces of the above Secret objects |
Required secrets for provisionVolume=true
:
Admin credentials are required for provisioning new volumes
adminID
: ID of an admin clientadminKey
: key of the admin client
Required secrets for provisionVolume=false
:
User credentials with access to an existing volume
userID
: ID of a user clientuserKey
: key of a user client
Notes on volume size: when provisioning a new volume, max_bytes
quota
attribute for this volume will be set to the requested volume size (see Ceph
quota documentation). A request
for a zero-sized volume means no quota attribute will be set.
Deployment with Kubernetes
Requires Kubernetes 1.13
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/cephfs/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-cephfsplugin-attacher.yaml
kubectl create -f csi-cephfsplugin-provisioner.yaml
Deploys stateful sets for external-attacher and external-provisioner sidecar containers for CSI CephFS.
Deploy CSI CephFS driver:
kubectl create -f csi-cephfsplugin.yaml
Deploys a daemon set with two containers: CSI driver-registrar and the CSI CephFS 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-cephfsplugin-attacher-0 1/1 Running 0 26s
pod/csi-cephfsplugin-provisioner-0 1/1 Running 0 25s
pod/csi-cephfsplugin-rljcv 2/2 Running 0 24s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/csi-cephfsplugin-attacher ClusterIP 10.104.116.218 <none> 12345/TCP 27s
service/csi-cephfsplugin-provisioner ClusterIP 10.101.78.75 <none> 12345/TCP 26s
...
You can try deploying a demo pod from examples/cephfs
to test the deployment further.
Notes on volume deletion
Volumes that were provisioned dynamically (i.e. provisionVolume=true
) are
allowed to be deleted by the driver as well, if the user chooses to do
so.Otherwise, the driver is forbidden to delete such volumes - attempting to
delete them is a no-op.