# 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 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 `cephcsi`. When compiled as an image, it's stored in the local Docker image store with name `cephcsi`. Building binary: ```bash make cephcsi ``` Building Docker image: ```bash 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` | `cephfs.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 | cephfs]` If the driver type is set to `rbd` it will act as a `rbd plugin` or if it's set to `cephfs` will act as a `cephfs plugin` `--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. `--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. `--instanceid` | "default" | Unique ID distinguishing this instance of Ceph CSI among other instances, when sharing Ceph clusters across CSI instances for provisioning `--metadatastorage` | _empty_ | Points to where older (1.0.0 or older plugin versions) metadata about provisioned volumes are kept, as file or in as k8s configmap (`node` or `k8s_configmap` respectively) **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 ----------------------------------------------------------------------------------------------------|--------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- `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 `fsName` | yes | CephFS filesystem name into which the volume shall be created `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. `pool` | yes | Ceph pool into which the volume shall be created `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 **NOTE:** An accompanying CSI configuration file, needs to be provided to the running pods. Refer to [Creating CSI configuration](../examples/README.md#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 for provisioning:** Admin credentials are required for provisioning new volumes * `adminID`: ID of an admin client * `adminKey`: key of the admin client **Required secrets for statically provisioned volumes:** User credentials with access to an existing volume * `userID`: ID of a user client * `userKey`: 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](http://docs.ceph.com/docs/mimic/cephfs/quota/)). 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](https://kubernetes.io/docs/concepts/storage/volumes/#mount-propagation), 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:** ```bash 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:** ```bash kubectl create -f csi-cephfsplugin-provisioner.yaml ``` Deploys stateful set of provision which includes external-provisioner ,external-attacher for CSI CephFS. **Deploy CSI CephFS driver:** ```bash kubectl create -f csi-cephfsplugin.yaml ``` Deploys a daemon set with two containers: CSI node-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: ```bash $ kubectl get all NAME READY STATUS RESTARTS AGE pod/csi-cephfsplugin-provisioner-0 3/3 Running 0 25s pod/csi-cephfsplugin-rljcv 2/2 Running 0 24s NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE service/csi-cephfsplugin-provisioner ClusterIP 10.101.78.75 12345/TCP 26s ... ``` Once the CSI plugin configuration is updated with details from a Ceph cluster of choice, you can try deploying a demo pod from examples/cephfs using the instructions [provided](../examples/README.md#deploying-the-storage-class) to test the deployment further. ### Notes on volume deletion Dynamically povisioned volumes are deleted by the driver, when requested to do so. Statically provisioned volumes, from plugin versions less than or equal to 1.0.0, are a no-op when a delete operation is performed against the same, and are expected to be deleted on the Ceph cluster by the user.