[incubator/kafka] Makes readiness probe configurable (#3948)

* Makes kafka readiness probe configurable

* Bumps version

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: 0.4.4
+version: 0.4.5
 keywords:
 - kafka
 - zookeeper

incubator/kafka/README.md

@@ -71,6 +71,11 @@ following configurable parameters:
 | `external.domain`              | Domain in which to advertise Kafka external listeners.                                                          | `cluster.local`                                            |
 | `external.init`                | External init container settings.                                                                               | (see `values.yaml`)                                        |
 | `configurationOverrides`       | `Kafka ` [configuration setting][brokerconfigs] overrides in the dictionary format                              | `{ offsets.topic.replication.factor: 3 }`                  |
+| `readinessProbe.initialDelaySeconds` | Number of seconds before probe is initiated.                                                              | `30`                                                       |
+| `readinessProbe.periodSeconds`       | How often (in seconds) to perform the probe.                                                              | `10`                                                       |
+| `readinessProbe.timeoutSeconds`      | Number of seconds after which the probe times out.                                                        | `5`                                                        |
+| `readinessProbe.successThreshold`    | Minimum consecutive successes for the probe to be considered successful after having failed.              | `1`                                                        |
+| `readinessProbe.failureThreshold`    | After the probe fails this many times, pod will be marked Unready.                                        | `3`                                                        |
 | `updateStrategy`               | StatefulSet update strategy to use.                                                                             | `{ type: "OnDelete" }`                                     |
 | `persistence.enabled`          | Use a PVC to persist data                                                                                       | `true`                                                     |
 | `persistence.size`             | Size of data volume                                                                                             | `1Gi`                                                      |

incubator/kafka/templates/statefulset.yaml

@@ -70,8 +70,11 @@ spec:
               - --zookeeper
               - {{ template "zookeeper.url" . }}
               - --list
-          initialDelaySeconds: 30
-          timeoutSeconds: 5
+          initialDelaySeconds: {{ .Values.readinessProbe.initialDelaySeconds }}
+          periodSeconds: {{ .Values.readinessProbe.periodSeconds }}
+          timeoutSeconds: {{ .Values.readinessProbe.timeoutSeconds }}
+          successThreshold: {{ .Values.readinessProbe.successThreshold }}
+          failureThreshold: {{ .Values.readinessProbe.failureThreshold }}
         ports:
         - containerPort: 9092
           name: kafka

incubator/kafka/values.yaml

@@ -51,6 +51,16 @@ affinity: {}
 ## ref: https://kubernetes.io/docs/concepts/configuration/assign-pod-node/#nodeselector
 nodeSelector: {}
 
+## Readiness probe config.
+## ref: https://kubernetes.io/docs/tasks/configure-pod-container/configure-liveness-readiness-probes/
+##
+readinessProbe:
+  initialDelaySeconds: 30
+  periodSeconds: 10
+  timeoutSeconds: 5
+  successThreshold: 1
+  failureThreshold: 3
+
 # Tolerations for nodes that have taints on them.
 # Useful if you want to dedicate nodes to just run kafka
 # https://kubernetes.io/docs/concepts/configuration/taint-and-toleration/