Use hostname for Baseboard::Pc::identifier field

[andrewjstone]

Doing this allows easier testbed setup and usage since we identify new sleds to add via their baseboard. In case we can't get a hostname we revert to using a UUID, as in the prior version of code.

[davepacheco]

I don't know enough to know if this change would create any problems. I think all the stuff I've done explicitly ignores non-Oxide hardware so I don't think that'll care. But it seems like this punts the uniqueness requirement to the deployer, who needs to ensure that hostnames are set properly and unique. I wonder if @jmpesp or @smklein has an opinion here?

[davepacheco]

I'm somewhat shocked that this isn't built in. Would it be better to use to use nix's implementation (since we're already using nix I think)?

Either way, I'd think we'd want to add this to the workspace-level deps.

[andrewjstone]

Good idea. I'll use nix's impl!

[andrewjstone]

Turns out we are not using nix. It is a transitive dep though.

[jclulow]

I think you probably want to try and use the SMBIOS UUID for this?

 $ smbios -t 1
ID    SIZE TYPE
1     79   SMB_TYPE_SYSTEM (type 1) (system information)

  Manufacturer: TYAN
  Product: B8036T65AV4E24HR
  Version: empty
  Serial Number: TCK2118F0004

  UUID: 00008036-4354-4245-3244-4b3033303031
  Wake-Up Event: 0x6 (power switch)
  SKU Number: empty
  Family: empty

It is often a unique property of the physical or virtual system on which you are running.

[rmustacc]

@jclulow we can't today due to it missing from Propolis (oxidecomputer/propolis#628). Which means that Falcon and co. don't have it.

[jclulow]

Ah! Very well.

[andrewjstone]

I don't know enough to know if this change would create any problems. I think all the stuff I've done explicitly ignores non-Oxide hardware so I don't think that'll care. But it seems like this punts the uniqueness requirement to the deployer, who needs to ensure that hostnames are set properly and unique. I wonder if @jmpesp or @smklein has an opinion here?

I tagged @jmpesp because he does the same thing for his petfood cluster in northern america.

[jmpesp]

🐶 🥫 approved