rook: 500 internal error to access dashboard in v0.9.1

Is this a bug report or feature request?

• Bug Report

Deviation from expected behavior:

The dashboard failed after create a 3 mon 3 osd cluster with the cluster configuration:

apiVersion: ceph.rook.io/v1
kind: CephCluster
metadata:
  name: rook-ceph
  namespace: rook-ceph
spec:
  cephVersion:
    image: ceph/ceph:v13.2.2-20181023
    allowUnsupported: false
  dataDirHostPath: /var/lib/rook
  # set the amount of mons to be started
  mon:
    count: 3
    allowMultiplePerNode: true
  # enable the ceph dashboard for viewing cluster status
  dashboard:
    enabled: true
    hostNetwork: false
  rbdMirroring:
    workers: 0
  resources:
  storage: # cluster level storage configuration and selection
    useAllNodes: false
    useAllDevices: false
    deviceFilter:
    location:
    config:
      databaseSizeMB: "1024" # this value can be removed for environments with normal sized disks (100 GB or larger)
      journalSizeMB: "1024"  # this value can be removed for environments with normal sized disks (20 GB or larger)
      osdsPerDevice: "1" # this value can be overridden at the node or device level
    nodes:
    - name: xxx.compute.internal
      devices:
      - name: "xvdg"
    - name: xxxx.compute.internal
      devices:
      - name: "xvdg"
    - name: xxxxx.compute.internal
      devices:
      - name: "xvdg"

Expected behavior:

How to reproduce it (minimal and precise):

Create a cluster with the docs. And

kubectl port-forward svc/rook-ceph-mgr-dashboard 8443:8443 -n rook-ceph

Then open https://localhost:8443 got error, I got logs from mgr:

[15/Jan/2019:10:13:03] ENGINE Error in HTTPServer.tick
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/cherrypy/wsgiserver/wsgiserver2.py", line 1837, in start
    self.tick()
  File "/usr/lib/python2.7/site-packages/cherrypy/wsgiserver/wsgiserver2.py", line 1902, in tick
    s, ssl_env = self.ssl_adapter.wrap(s)
  File "/usr/lib/python2.7/site-packages/cherrypy/wsgiserver/ssl_builtin.py", line 52, in wrap
    keyfile=self.private_key, ssl_version=ssl.PROTOCOL_SSLv23)
  File "/usr/lib64/python2.7/ssl.py", line 934, in wrap_socket
    ciphers=ciphers)
  File "/usr/lib64/python2.7/ssl.py", line 609, in __init__
    self.do_handshake()
  File "/usr/lib64/python2.7/ssl.py", line 831, in do_handshake
    self._sslobj.do_handshake()
SSLError: [SSL: HTTP_REQUEST] http request (_ssl.c:579)

Environment:

• OS (e.g. from /etc/os-release): ubuntu 16.04
• Kernel (e.g. uname -a): Linux xxxx 4.4.0-141-generic #167-Ubuntu SMP Wed Dec 5 10:40:15 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
• Cloud provider or hardware configuration: aws
• Rook version (use rook version inside of a Rook Pod): v0.9.0
• Kubernetes version (use kubectl version): v1.13.2
• Kubernetes cluster type (e.g. Tectonic, GKE, OpenShift): bare metal
• Storage backend status (e.g. for Ceph use ceph health in the Rook Ceph toolbox): HEALTH_WARN mon c is low on available space