Problem

$ helm install kubernetes-dashboard stable/kubernetes-dashboard --namespace MY_NAMESPACE --set ingress.enabled=true --set ingress.hosts={MYDASHBOARD.EXAMPLE.COM} --set-string ingress.annotations."nginx\.ingress\.kubernetes\.io/secure-backends"="true"
Error: UPGRADE FAILED: failed to create patch: failed to get versionedObject: unable to convert unstructured object to extensions/v1beta1, Kind=Ingress: unrecognized type: string

NB: A fix for the --set-string flag is on the way: helm/helm#4142

Workaround

Create file dashboard-values.yaml:

ingress:
  annotations:
    "nginx.ingress.kubernetes.io/secure-backends": "true"

Run command:

$ helm install kubernetes-dashboard stable/kubernetes-dashboard --namespace YOUR_NAMESPACE --set ingress.enabled=true --set ingress.hosts={MYDASHBOARD.EXAMPLE.COM} -f dashboard-values.yaml

References

• Helm: https://github.com/kubernetes/helm
• kubernetes-dashboard chart: https://github.com/kubernetes/charts/tree/master/stable/kubernetes-dashboard