Core: media_player.universal not showing cover for child media_player.roku

[ofuangka]

Home Assistant release with the issue:
0.70.1

Operating environment (Hass.io/Docker/Windows/etc.):
ArchLinux

Component/platform:
https://www.home-assistant.io/components/media_player.universal/

Description of problem:
media_player.universal with child media_player.roku has a white cover image. media_player.roku has a correct cover image

Problem-relevant configuration.yaml entries and (fill out even if it seems unimportant):

media_player:
  - platform: universal
    name: TV
    children:
      - media_player.roku

Traceback (if applicable):

Jun 02 23:05:05 xxx hass[11469]: 2018-06-02 23:05:05 ERROR (MainThread) [homeassistant.core] Error doing job: Task exception was never retrieved
Jun 02 23:05:05 xxx hass[11469]: Traceback (most recent call last):
Jun 02 23:05:05 xxx hass[11469]:   File "/var/lib/homeassistant/.venv/lib/python3.6/site-packages/homeassistant/components/media_player/__init__.py", line 977, in send_image
Jun 02 23:05:05 xxx hass[11469]:     data, content_type = await player.async_get_media_image()
Jun 02 23:05:05 xxx hass[11469]:   File "/var/lib/homeassistant/.venv/lib/python3.6/site-packages/homeassistant/components/media_player/__init__.py", line 511, in async_get_media_image
Jun 02 23:05:05 xxx hass[11469]:     return await _async_fetch_image(self.hass, url)
Jun 02 23:05:05 xxx hass[11469]:   File "/var/lib/homeassistant/.venv/lib/python3.6/site-packages/homeassistant/components/media_player/__init__.py", line 909, in _async_fetch_image
Jun 02 23:05:05 xxx hass[11469]:     response = await websession.get(url)
Jun 02 23:05:05 xxx hass[11469]:   File "/var/lib/homeassistant/.venv/lib/python3.6/site-packages/aiohttp/client.py", line 313, in _request
Jun 02 23:05:05 xxx hass[11469]:     ssl=ssl, proxy_headers=proxy_headers, traces=traces)
Jun 02 23:05:05 xxx hass[11469]:   File "/var/lib/homeassistant/.venv/lib/python3.6/site-packages/aiohttp/client_reqrep.py", line 210, in __init__
Jun 02 23:05:05 xxx hass[11469]:     self.update_host(url)
Jun 02 23:05:05 xxx hass[11469]:   File "/var/lib/homeassistant/.venv/lib/python3.6/site-packages/aiohttp/client_reqrep.py", line 253, in update_host
Jun 02 23:05:05 xxx hass[11469]:     raise InvalidURL(url)
Jun 02 23:05:05 xxx hass[11469]: aiohttp.client_exceptions.InvalidURL: /api/media_player_proxy/media_player.roku?token=xxx&cache=xxx

Additional information:

[jamesw4]

I think this might be a general issue with the universal media player. I also have this issue for the past few versions of HASSIO. Currently on 0.71.0. I've got one setup with three children (kodi, ps4, custom media player) and the universal player shows a blank white image for all three. The individual media players them selves in home assistant show the images fine.

[colindunn]

I have the same issue for the last few versions too. I suspect it's to do with the using the proxy for another entity_id and being rejected but I haven't had the chance to trace it yet

[azogue]

Hi, I have the same error with Kodi, using it under the universal player and using it alone. I couldn't debug it, but i've checked that the error is occurring because that url is not absolute.

The method is called 2 times. The first time is for the HA proxy, the second (if the url is absolute) is the origin url (in my case, a url in the Kodi host).

I'll try to make a quick fix