[incubator/cassandra] Pod disruption budget (#8381)

* Pod distruption budget

Signed-off-by: Maciej Bryński <maciej.brynski@xcaliber.com>

* Fix pdb definition

Signed-off-by: Maciej Bryński <maciej.brynski@xcaliber.com>

incubator/cassandra/Chart.yaml

@@ -1,5 +1,5 @@
 name: cassandra
-version: 0.8.0
+version: 0.9.0
 appVersion: 3.11.3
 description: Apache Cassandra is a free and open-source distributed database management
   system designed to handle large amounts of data across many commodity servers, providing

incubator/cassandra/README.md

@@ -105,6 +105,7 @@ The following table lists the configurable parameters of the Cassandra chart and
 | `resources`                          | CPU/Memory resource requests/limits             | Memory: `4Gi`, CPU: `2`                                    |
 | `service.type`                       | k8s service type exposing ports, e.g. `NodePort`| `ClusterIP`                                                |
 | `podManagementPolicy`                | podManagementPolicy of the StatefulSet          | `OrderedReady`                                             |
+| `podDisruptionBudget`                | Pod distruption budget                          | `{}`                                                       |
 | `podAnnotations`                     | pod annotations for the StatefulSet             | `{}`                                                       |
 | `updateStrategy.type`                | UpdateStrategy of the StatefulSet               | `OnDelete`                                                 |
 | `livenessProbe.initialDelaySeconds`  | Delay before liveness probe is initiated        | `90`                                                       |

incubator/cassandra/templates/pdb.yaml

@@ -0,0 +1,17 @@
+{{- if .Values.podDisruptionBudget -}}
+apiVersion: policy/v1beta1
+kind: PodDisruptionBudget
+metadata:
+  labels:
+    app: {{ template "cassandra.name" . }}
+    chart: {{ .Chart.Name }}-{{ .Chart.Version }}
+    heritage: {{ .Release.Service }}
+    release: {{ .Release.Name }}
+  name: {{ template "cassandra.fullname" . }}
+spec:
+  selector:
+    matchLabels:
+      app: {{ template "cassandra.name" . }}
+      release: {{ .Release.Name }}
+{{ toYaml .Values.podDisruptionBudget | indent 2 }}
+{{- end -}}

incubator/cassandra/values.yaml

@@ -104,6 +104,11 @@ podSettings:
   # Change this to give pods more time to properly leave the cluster when not using persistent storage.
   terminationGracePeriodSeconds: 30
 
+## Pod distruption budget
+podDisruptionBudget: {}
+  # maxUnavailable: 1
+  # minAvailable: 2
+
 podManagementPolicy: OrderedReady
 updateStrategy:
   type: OnDelete