helm: update rbd provisioner updateStrategy

Update ceph-csi-rbd.provisioner updatestrategy
to allow maxUnavailable pods at a time to be 50%

Signed-off-by: Yug Gupta <yuggupta27@gmail.com>
(cherry picked from commit ea088d40be)

charts/ceph-csi-rbd/templates/provisioner-deployment.yaml

@@ -11,6 +11,12 @@ metadata:
     heritage: {{ .Release.Service }}
 spec:
   replicas: {{ .Values.provisioner.replicaCount }}
+  strategy:
+    type: {{ .Values.provisioner.strategy.type }}
+{{- if eq .Values.provisioner.strategy.type "RollingUpdate" }}
+    rollingUpdate:
+      maxUnavailable: {{ .Values.provisioner.strategy.rollingUpdate.maxUnavailable }}
+{{- end }}
   selector:
     matchLabels:
       app: {{ include "ceph-csi-rbd.name" . }}

charts/ceph-csi-rbd/values.yaml

@@ -117,6 +117,14 @@ nodeplugin:
 provisioner:
   name: provisioner
   replicaCount: 3
+  strategy:
+    # RollingUpdate strategy replaces old pods with new ones gradually,
+    # without incurring downtime.
+    type: RollingUpdate
+    rollingUpdate:
+      # maxUnavailable is the maximum number of pods that can be
+      # unavailable during the update process.
+      maxUnavailable: 50%
   # if fstype is not specified in storageclass, ext4 is default
   defaultFSType: ext4
   # deployController to enable or disable the deployment of controller which