Add podAntiAffinity (#3892)

incubator/cassandra/Chart.yaml

@@ -1,5 +1,5 @@
 name: cassandra
-version: 0.2.3
+version: 0.2.4
 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
   high availability with no single point of failure.

incubator/cassandra/templates/cassandra-statefulset.yaml

@@ -65,6 +65,10 @@ spec:
         fsGroup: {{ .Values.securityContext.fsGroup }}
         runAsUser: {{ .Values.securityContext.runAsUser }}
       {{- end }}
+{{- if .Values.affinity }}
+      affinity:
+{{ toYaml .Values.affinity | indent 8 }}
+{{- end }}
       containers:
       - name: {{ template "cassandra.fullname" . }}
         image: "{{ .Values.image.repo }}:{{ .Values.image.tag }}"

incubator/cassandra/values.yaml

@@ -81,3 +81,7 @@ securityContext:
   enabled: false
   fsGroup: 999
   runAsUser: 999
+
+## Affinity for pod assignment
+## Ref: https://kubernetes.io/docs/concepts/configuration/assign-pod-node/#affinity-and-anti-affinity
+affinity: {}