Backport of [NET-6232] Helm Chart: Support StatefulSet PVC retention into release/1.2.x

.changelog/3180.txt

@@ -0,0 +1,3 @@
+```release-note:feature
+helm: add persistentVolumeClaimRetentionPolicy variable for managing Statefulsets PVC retain policy when deleting or downsizing the statefulset.
+```

charts/consul/templates/server-statefulset.yaml

@@ -44,6 +44,9 @@ spec:
     rollingUpdate:
       partition: {{ .Values.server.updatePartition }}
   {{- end }}
+  {{- if and (semverCompare ">= 1.23-0" .Capabilities.KubeVersion.Version) (.Values.server.persistentVolumeClaimRetentionPolicy) }}
+  persistentVolumeClaimRetentionPolicy: {{ toYaml .Values.server.persistentVolumeClaimRetentionPolicy | nindent 4 }}
+  {{- end }}
   selector:
     matchLabels:
       app: {{ template "consul.name" . }}

charts/consul/test/unit/server-statefulset.bats

@@ -196,6 +196,73 @@ load _helpers
   [ "${actual}" = "foo" ]
 }
 
+#--------------------------------------------------------------------
+# persistentVolumeClaimRetentionPolicy
+
+@test "server/StatefulSet: persistentVolumeClaimRetentionPolicy not set by default when kubernetes < 1.23" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      -s templates/server-statefulset.yaml  \
+      --kube-version "1.22" \
+      . | tee /dev/stderr |
+      yq -r '.spec.persistentVolumeClaimRetentionPolicy' | tee /dev/stderr)
+  [ "${actual}" = "null" ]
+}
+
+@test "server/StatefulSet: unset persistentVolumeClaimRetentionPolicy.whenDeleted when kubernetes < 1.23" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      -s templates/server-statefulset.yaml  \
+      --kube-version "1.22" \
+      --set 'server.persistentVolumeClaimRetentionPolicy.whenDeleted=Delete' \
+      . | tee /dev/stderr |
+      yq -r '.spec.persistentVolumeClaimRetentionPolicy.whenDeleted' | tee /dev/stderr)
+  [ "${actual}" = "null" ]
+}
+
+@test "server/StatefulSet: unset persistentVolumeClaimRetentionPolicy.whenScaled when kubernetes < 1.23" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      -s templates/server-statefulset.yaml  \
+      --kube-version "1.22" \
+      --set 'server.persistentVolumeClaimRetentionPolicy.whenScaled=Delete' \
+      . | tee /dev/stderr |
+      yq -r '.spec.persistentVolumeClaimRetentionPolicy.whenScaled' | tee /dev/stderr)
+  [ "${actual}" = "null" ]
+}
+
+@test "server/StatefulSet: persistentVolumeClaimRetentionPolicy not set by default when kubernetes >= 1.23" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      -s templates/server-statefulset.yaml  \
+      --kube-version "1.23" \
+      . | tee /dev/stderr |
+      yq -r '.spec.persistentVolumeClaimRetentionPolicy' | tee /dev/stderr)
+  [ "${actual}" = "null" ]
+}
+
+@test "server/StatefulSet: can set persistentVolumeClaimRetentionPolicy.whenDeleted when kubernetes >= 1.23" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      -s templates/server-statefulset.yaml  \
+      --kube-version "1.23" \
+      --set 'server.persistentVolumeClaimRetentionPolicy.whenDeleted=Delete' \
+      . | tee /dev/stderr |
+      yq -r '.spec.persistentVolumeClaimRetentionPolicy.whenDeleted' | tee /dev/stderr)
+  [ "${actual}" = "Delete" ]
+}
+
+@test "server/StatefulSet: can set persistentVolumeClaimRetentionPolicy.whenScaled when kubernetes >= 1.23" {
+  cd `chart_dir`
+  local actual=$(helm template \
+      -s templates/server-statefulset.yaml  \
+      --kube-version "1.23" \
+      --set 'server.persistentVolumeClaimRetentionPolicy.whenScaled=Delete' \
+      . | tee /dev/stderr |
+      yq -r '.spec.persistentVolumeClaimRetentionPolicy.whenScaled' | tee /dev/stderr)
+  [ "${actual}" = "Delete" ]
+}
+
 #--------------------------------------------------------------------
 # serverCert
 

charts/consul/values.yaml

@@ -864,6 +864,21 @@ server:
   # @type: string
   storageClass: null
 
+  # The [Persistent Volume Claim (PVC) retention policy](https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/#persistentvolumeclaim-retention)
+  # controls if and how PVCs are deleted during the lifecycle of a StatefulSet.
+  # WhenDeleted specifies what happens to PVCs created from StatefulSet VolumeClaimTemplates when the StatefulSet is deleted, 
+  # and WhenScaled specifies what happens to PVCs created from StatefulSet VolumeClaimTemplates when the StatefulSet is scaled down.
+  # 
+  # Example:
+  #
+  # ```yaml
+  # persistentVolumeClaimRetentionPolicy:
+  #   whenDeleted: Retain
+  #   whenScaled: Retain
+  # ```
+  # @type: map
+  persistentVolumeClaimRetentionPolicy: null
+
   # This will enable/disable [service mesh](https://developer.hashicorp.com/consul/docs/connect). Setting this to true
   # _will not_ automatically secure pod communication, this
   # setting will only enable usage of the feature. Consul will automatically initialize