Netdata identifiers are not properly handled

[fabaff]

Home Assistant release with the issue:
0.71

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

Component/platform:
https://www.home-assistant.io/components/sensor.netdata/

Description of problem:

Multiple entries for the same resource will not work as they don't pass configuration validation.

    resources:
      cpu.cpufreq:
        element: cpu0
      cpu.cpufreq:
        element: cpu1

There are some deviation in the naming of values in the frontend and the RESTful API. In the documentation is stated that the frontend should be used to determine the name of the data_group. E.g., for hddtemp is the frontend using hddtemp_local.disks_temp and the API hddtemp_local.temperatures.

"hddtemp_local.temperatures":{  
   "name":"hddtemp_local.disks_temp",
   "context":"hddtemp.temperatures",
   "units":"Celsius",
   "last_updated":1528578157,
   "dimensions":{  
      "sda":{  
         "name":"sda",
         "value":45
      }
   }
},

This seems also be the case for network metrics. InOctets instead of received.

"system.ipv4":{  
   "name":"system.ipv4",
   "context":"system.ipv4",
   "units":"kilobits/s",
   "last_updated":1528578181,
   "dimensions":{  
      "InOctets":{  
         "name":"received",
         "value":2.4819415
      },
      "OutOctets":{  
         "name":"sent",
         "value":-2.4589827
      }
   }
},

It may happen at other places as well.

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

sensor:
  - platform: netdata
    resources:
      hddtemp_local.disks_temp:
        element: sda
 
sensor:
  - platform: netdata
    resources:
      system.ipv4:
        element: received

Additional information:
Initial report: https://community.home-assistant.io/t/netdata-configuration/55712

[fabaff]

home-assistant/home-assistant.io#5528 contains details to get valid names for the elements to monitor.

[LarsNorgaard]

Is multiply element(s) supported?

sensors.acpitz-virtual-0_temperature:
    element: 
     - acpitz-virtual-0_temp1
     - acpitz-virtual-0_temp2

[Redferne]

    system.ram:
      element:
      - free
      - used
      - cached
      - buffers

2018-07-01 16:32:16 ERROR (MainThread) [homeassistant.components.sensor] netdata: Error on device update!
Traceback (most recent call last):
  File "/srv/homeassistant/lib/python3.6/site-packages/homeassistant/helpers/entity_platform.py", line 248, in _async_add_entity
    await entity.async_device_update(warning=False)
  File "/srv/homeassistant/lib/python3.6/site-packages/homeassistant/helpers/entity.py", line 317, in async_device_update
    yield from self.async_update()
  File "/srv/homeassistant/lib/python3.6/site-packages/homeassistant/components/sensor/netdata.py", line 134, in async_update
    resource_data['dimensions'][self._element]['value'], 2)
KeyError: "['free', 'used', 'cached', 'buffers']"

[fabaff]

No support for multiple elements at the moment.

A PR would be welcome.

[balloobbot]

There hasn't been any activity on this issue recently. Due to the high number of incoming GitHub notifications, we have to clean some of the old issues, as many of them have already been resolved with the latest updates.

Please make sure to update to the latest Home Assistant version and check if that solves the issue. Let us know if that works for you by adding a comment 👍

[fabaff]

Was change with #16656.