[incubator/kafka] Adding the ability to define a pod disruption budget for brokers (#15345)

* feature: adding the ability to define a pod disruption budget to the kafka brokers

Signed-off-by: Kealan Murphy <kealan.murphy@aspect.com>

* address PR comments

Signed-off-by: Kealan Murphy <kealan.murphy@aspect.com>

* bump chart version

Signed-off-by: Murphy, Kealan <kealan.murphy@aspect.com>

incubator/kafka/Chart.yaml

@@ -2,7 +2,7 @@ apiVersion: v1
 description: Apache Kafka is publish-subscribe messaging rethought as a distributed
   commit log.
 name: kafka
-version: 0.17.0
+version: 0.17.1
 appVersion: 5.0.1
 keywords:
 - kafka

incubator/kafka/README.md

@@ -84,6 +84,7 @@ following configurable parameters:
 | `external.loadBalancerIP`                      | Add Static IP to the type Load Balancer. Depends on the provider if enabled                | `[]`
 | `podAnnotations`                               | Annotation to be added to Kafka pods                                                                                                                                     | `{}`                                                               |
 | `podLabels`                                    | Labels to be added to Kafka pods                                                                                                                                     | `{}`                                                               |
+| `podDisruptionBudget`                          | Define a Disruption Budget for the Kafka Pods                                                                                                                                    | `{}`                                                               |
 | `envOverrides`                                 | Add additional Environment Variables in the dictionary format                       | `{ zookeeper.sasl.enabled: "False" }`                              |
 | `configurationOverrides`                       | `Kafka ` [configuration setting][brokerconfigs] overrides in the dictionary format                                                                                       | `{ "confluent.support.metrics.enable": false }`                          |
 | `secrets`                                      | Pass any secrets to the kafka pods. Each secret will be passed as an environment variable by default. The secret can also be mounted to a specific path if required. Environment variable names are generated as: `<secretName>_<secretKey>` (All upper case) | `{}` |

incubator/kafka/templates/podisruptionbudget.yaml

@@ -0,0 +1,18 @@
+{{- if .Values.podDisruptionBudget }}
+apiVersion: policy/v1beta1
+kind: PodDisruptionBudget
+metadata:
+  name: {{ include "kafka.fullname" . }}
+  labels:
+    app: {{ template "kafka.name" . }}
+    chart: {{ template "kafka.chart" . }}
+    release: {{ .Release.Name }}
+    heritage: {{ .Release.Service }}
+spec:
+  selector:
+    matchLabels:
+      app: {{ template "kafka.name" . }}
+      release: {{ .Release.Name }}
+{{ toYaml .Values.podDisruptionBudget | indent 2 }}
+
+{{- end }}

incubator/kafka/values.yaml

@@ -163,6 +163,8 @@ podLabels: {}
   # service: broker
   # team: developers
 
+podDisruptionBudget: {}
+  # maxUnavailable: 1  # Limits how many Kafka pods may be unavailable due to voluntary disruptions.
 
 ## Configuration Overrides. Specify any Kafka settings you would like set on the StatefulSet
 ## here in map format, as defined in the official docs.