PrometheusRule cannot be created

[peske]

I've tried to create a PrometheusRule resource by using chart, and for that reason I have the following in my values file:

metrics:
  enabled: true
  port: 5001
  serviceMonitor:
    enabled: true
    labels:
      release: kube-prometheus-release
  prometheusRule:
    enabled: true
    labels:
      release: kube-prometheus-release
    rules: {}

However, when I try helm upgrade, I get the following error:

Error: UPGRADE FAILED: failed to create resource: PrometheusRule.monitoring.coreos.com "docker-registry" is invalid: spec: Required value

It looks that there's a problem with PrometheusRule template.

[peske]

It's probably because I've left empty rules. However, it would be nice if the chart handles that better.