pkesavap / csi-driver

oVirt's CSI driver for Openshift and Kubernetes

oVirt CSI driver

Implementation of a CSI driver for oVirt.

This work is a continuation of the work done in github.com/ovirt/ovirt-openshift-extensions, and is the future of the development of a storage driver for oVirt.

This repo also contains an operator to deploy the driver on OpenShift or Kubernetes with most of the code based on openshift/csi-operator.

Prerequisites

Before installation, please ensure that you are running a k8s cluster which supports the CSI implementation, such as Openshift

Installation

Openshift/OKD 4:

• Clone this repository
• Ensure that you have oc installed locally
• Run:

  export KUBECONFIG=</path/to/your>/auth/kubeconfig
  oc create -f deploy/csi-driver
  

• validate:

  export KUBECONFIG=</path/to/your>/auth/kubeconfig
  oc get pods -n ovirt-csi-driver
  oc new-project zzz-test
  oc create -f deploy/csi-driver/example
  oc get pods -n zzz-test
  

Examples for StorageClass, PVC and Pod:

StorageClass:

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: ovirt-csi-sc
  annotations:
    storageclass.kubernetes.io/is-default-class: "true"
provisioner: csi.ovirt.org
parameters:
  # the name of the oVirt storage domain. "nfs" is just an example.
  storageDomainName: "nfs"
  thinProvisioning: "true"

PVC:

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: 1g-ovirt-cow-disk
  annotations:
    volume.beta.kubernetes.io/storage-class: ovirt-csi-sc
spec:
  storageClassName: ovirt-csi-sc
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi

Pod:

apiVersion: v1 
kind: Pod 
metadata:
  name: testpodwithcsi
spec:
  containers:
  - image: busybox
    name: testpodwithcsi
    command: ["sh", "-c", "while true; do ls -la /opt; echo this file system was made availble using ovirt csi driver; sleep 1m; done"]
    imagePullPolicy: Always
    volumeMounts:
    - name: pv0002
      mountPath: "/opt"
  volumes:
  - name: pv0002
    persistentVolumeClaim:
      claimName: 1g-ovirt-cow-disk

Kubernetes:

• tbc

Development

Deploy

• operator
• dev/test

OpenShift vs Kubernetes

• credential requests (CredentialRequest) require the openshift cloud credentials operator in order to provision. You will need to either deploy the operator and create the ovirt-credentials secret in the kube-system namespace, or provision the ovirt-credentials secret yourself into the ovirt-csi-driver namespace.

Troubleshooting

Get all the objects for the CSI driver

$ oc get all -n ovirt-csi-driver
NAME                       READY   STATUS            RESTARTS   AGE
pod/ovirt-csi-node-2nptq   0/2     PodInitializing   0          2d23h
pod/ovirt-csi-node-7t266   2/2     Running           0          15m
pod/ovirt-csi-plugin-0     0/3     PodInitializing   0          2d23h

NAME                            DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR   AGE
daemonset.apps/ovirt-csi-node   1         1         1       1            1           <none>          2d23h

NAME                                READY   AGE
statefulset.apps/ovirt-csi-plugin   0/1     2d23h

ovirt-csi-plugin is a pod, that is part of the StatefulSet, running the controller's logic (create volume, delete volume, attach volume and more). It runs the following containers: csi-external-attacher (triggers ControllerPublish/UnpublishVolume), csi-external-provisioner (mainly for Create/DeleteVolume) and ovirt-csi-driver.

ovirt-csi-node is a DaemonSet running the csi-driver-registrar (provides information about the driver with GetPluginInfo and GetPluginCa pabilities) and ovirt-csi-driver.

The sidecar containers (csi-external-attacher, csi-external-provisioner, csi-driver-registrar) run alongside ovirt-csi-driver and run its code via gRPC.

Get inside the pod's containers:

oc -n ovirt-csi-driver rsh -c <container name> pod/ovirt-csi-node-2nptq

Watch logs:

oc logs pods/ovirt-csi-node-2nptq -n ovirt-csi-driver -c <container name> | less