In the stateful set off the common/cassandara/templates/statefulset.yaml the spec for the image looks like

piVersion: apps/v1
kind: StatefulSet
metadata: {{- include "common.resourceMetadata" . | nindent 2 }}
spec:
...

containers:

• name: {{ include "common.name" . }}
  image: {{ .Values.image }}
  imagePullPolicy: {
  Unknown macro: { .Values.global.pullPolicy | default .Values.pullPolicy }

  }

The problem is the at the image doesn't include a repository section which can make it difficult to reconfigure in non public deployments