Support online volume expansion

Summary:
Online volume expansion is a 2 phase process:

1. The backing storage, in this case the raw file, needs to be resized. (i.e. `truncate -s`)
2. The node should be notified, so that it can both refresh its device capacity (i.e. `losetup -c`) and resize the filesystem (`resize2fs`) accordingly.

Although in our case both steps could be performed on the node itself, for the sake of following the semantics of how volume expansion works, we perform step 1 from the controller, and step 2 from the node.

Also, the `external-resizer` component is added which watches for PVC size updates, and notifies the CSI controller about it.

Test Plan:
Setup:
- Deploy
- Create a rawfile-backed pvc, and attach a Deployment to it
- Keep an eye on `rawfile` pod logs in `kube-system` namespace to see if any errors pop out during all scenarios

Scenario 1:
- Increase the size of the pvc
- Exec into the pod and verify that the volume is resized indeed (using `df`)

Scenario 2:
- Decrease deployment's replica to 0
- Increase the size of the pvc. Wait for a couple of minutes.
- Increase deployment's replica to 1
- Exec into the pod and verify that the volume is resized indeed.

Reviewers: bghadiri, mhyousefi, h.marvi, sina_rad

Reviewed By: bghadiri, mhyousefi, sina_rad

Differential Revision: https://phab.hamravesh.ir/D817

deploy/charts/rawfile-csi/templates/00-rbac.yaml

@@ -75,3 +75,40 @@ roleRef:
   kind: ClusterRole
   name: {{ include "rawfile-csi.fullname" . }}-broker
   apiGroup: rbac.authorization.k8s.io
+---
+kind: ClusterRole
+apiVersion: rbac.authorization.k8s.io/v1
+metadata:
+  name: {{ include "rawfile-csi.fullname" . }}-resizer
+rules:
+  - apiGroups: [""]
+    resources: ["secrets"]
+    verbs: ["get", "list", "watch"]
+  - apiGroups: [""]
+    resources: ["persistentvolumes"]
+    verbs: ["get", "list", "watch", "patch"]
+  - apiGroups: [""]
+    resources: ["persistentvolumeclaims"]
+    verbs: ["get", "list", "watch"]
+  - apiGroups: [""]
+    resources: ["pods"]
+    verbs: ["get", "list", "watch"]
+  - apiGroups: [""]
+    resources: ["persistentvolumeclaims/status"]
+    verbs: ["patch"]
+  - apiGroups: [""]
+    resources: ["events"]
+    verbs: ["list", "watch", "create", "update", "patch"]
+---
+kind: ClusterRoleBinding
+apiVersion: rbac.authorization.k8s.io/v1
+metadata:
+  name: {{ include "rawfile-csi.fullname" . }}-resizer
+subjects:
+  - kind: ServiceAccount
+    name: {{ include "rawfile-csi.fullname" . }}-driver
+    namespace: {{ .Release.Namespace }}
+roleRef:
+  kind: ClusterRole
+  name: {{ include "rawfile-csi.fullname" . }}-resizer
+  apiGroup: rbac.authorization.k8s.io

deploy/charts/rawfile-csi/templates/01-controller-plugin.yaml

@@ -64,3 +64,14 @@ spec:
           volumeMounts:
             - name: socket-dir
               mountPath: /csi
+        - name: csi-resizer
+          image: quay.io/k8scsi/csi-resizer:v0.5.0
+          imagePullPolicy: IfNotPresent
+          args:
+            - "--csi-address=$(ADDRESS)"
+          env:
+            - name: ADDRESS
+              value: /csi/csi.sock
+          volumeMounts:
+            - name: socket-dir
+              mountPath: /csi