identify a device via its subchannel

[Christian Ehrhardt ]

In the s390x world people identify all devices (except the fairly new pci devices) via their subchannel.
It would be great to have that reflected as a match in the yaml.

Currently the subchannel is rendered into the device name like subchannel "c000" becomes "encc000" and that is how you identify your cards. Yet traditionally I'm sure people would like to identify by "just" the subchannel.

Currently neither networkd nor NetworkManager expose anything for that so the effort would be huge for something small. Still I'd keep it open for discussion at least.

[Martin Pitt (pitti)]

I'm afraid I don't know what that means, this might be a z series specific concept? This isn't exposed by networkd or NM directly, but it might be possible that the subchannel is part of the ifnames generated name so that you can use a name glob?

[Martin Pitt (pitti)]

Err sorry, that was copy&paste'd from the mailing list. So it seems that *is* exposed as part of the name, so

  match:
    name: "en*c000*"

might just do what you want?

[Christian Ehrhardt  (paelzer)]

Yes, as I stated before that would do it.
As I said it would be just about eliminating the remaining "en" portion and sound more platform aware which appears as a saner configuration to the end user.

So right on parsing this:
match:
  subchannel: "c000"

Could be converted internally to:
  match:
    name: "encc000"

Benefits:
- If there ever would be a change to the leading "enc" netplan could take care
- Configuration reads as a System z admin would expect it (subchannel being the primary identifier)

[Lukas Märdian (slyon)]

Migrating this to the "netplan" project. "nplan" is no more.