Add mdev as a diagnostic sensor for the ping integration

[parautenbach]

Describe your core improvement

The ping sensor's attributes where removed and added as diagnostic sensors, except for the mdev measurement.

home-assistant/core#112004

Current limitations

I had to create a command line sensor to replicate the functionality that existed previously.

  - sensor:
      name: internet_round_trip_time_mdev
      command: "ping -c 5 www.google.com 2>/dev/null | grep -oP '(?<=rtt min/avg/max/mdev = )[^ ]+' | awk -F'/' '{print $4}' || echo 0"
      command_timeout: 15
      unit_of_measurement: "ms"
      value_template: '{{ value | float(0) }}'

Technical benefits

No need for technically less apt users to need to implement this. I'm assuming this was also a simple, accidental oversight.

Additional context

No response

[jpbede]

mdev as a sensor (https://github.com/home-assistant/core/blob/dev/homeassistant/components/ping/sensor.py#L52-L62) is there but only if we fallback to native ping command of the OS. Under normal circumstances (HA has the right to create sockets) we use icmplib (https://github.com/ValentinBELYN/icmplib), which is a pure Python ping implementation, which does not support mdev.
Before that the mdev attribute worked the same way and was also only used when we fallback to the native ping.

[jpbede]

Does that affect which implementation is used?

Yes, when HA does not have the permission to create sockets than we fallback to the native ping. So in the container HA has the permission to create a socket, so we use icmplib.

To be honest, I've been using mdev as a kind of proxy for jitter, which is actually the more useful metric to have. I see icmplib measures jitter.

Yea sure, I can make jitter available as a sensor 🙂

[parautenbach]

Awesome!

Do I need to mark a post as the answer, or is that done by you, or another HA dev team member or contributor?

[jpbede]

As soon as I've done the PR and posted the link, you/I can mark the post as done 🙂

[jpbede]

There you go: home-assistant/core#149899
Once this has been merged, it will be available in the 2025.9 release.

[parautenbach]

Thanks a mil! That was quick. I'll grab it in the next release.