Support custom rules for read-only mode (#7152)

* Support custom rules for read-only mode

When dashboard is started with read-only role, CRDs are not shown in UI due to permissions issue.
This PR adds ability to provide custom rules for read-only role

* Update aio/deploy/helm-chart/kubernetes-dashboard/Chart.yaml

Co-authored-by: Cédric de Saint Martin <cdesaintmartin@wiremind.io>

Co-authored-by: Cédric de Saint Martin <cdesaintmartin@wiremind.io>

aio/deploy/helm-chart/kubernetes-dashboard/Chart.yaml

@@ -14,7 +14,7 @@
 
 apiVersion: v2
 name: kubernetes-dashboard
-version: 5.8.0
+version: 5.9.0
 appVersion: 2.6.1
 description: General-purpose web UI for Kubernetes clusters
 keywords:

aio/deploy/helm-chart/kubernetes-dashboard/templates/clusterrole-readonly.yaml

@@ -151,4 +151,7 @@ rules:
       - get
       - list
       - watch
+  {{- with .Values.rbac.clusterReadOnlyRoleAdditionalRules -}}
+  {{ toYaml . | nindent 2 }}
+  {{- end }}
 {{- end -}}

aio/deploy/helm-chart/kubernetes-dashboard/values.yaml

@@ -305,6 +305,9 @@ rbac:
   #
   # Independent from rbac.create parameter.
   clusterReadOnlyRole: false
+  # It is possible to add additional rules if read only role is enabled.
+  # This can be useful, for example, to show CRD resources.
+  # clusterReadOnlyRoleAdditionalRules: []
 
 serviceAccount:
   # Specifies whether a service account should be created