Adapt network interfaces sorting

[changlei-li]

This PR is the adaption of #6381 in networkd and xapi.
XS8: Keep the legacy behaviour, use host-installer, sort-script to sort and rename the network interfaces to ethx.
XS9: Use Network_device_order.sort to sort the interfaces, store the result in networkd config.interface_order.
Compatibility is offered by check the sort-script interface-rename-data dir.
Add new interface Interface.get_interface_positions to pass interfaces and positions from networkd to xapi.

[minglumlu]

Could this be done within Interface.get_all?

[changlei-li]

I prefer to add a new interface to keep the interface function simple and not modify the old one for potential break.

[minglumlu]

OK. I thought it's would be simpler to include this in the Interface.get_all from the interface design's point of view. But I'm not sure about this.
Hi @robhoes @psafont @lindig
May I please have your thoughts on this?

BTW, a minor comment on the name: Interface.get_interface_positions seems a bit redundant. If we are going to use this, how about Interface.get_order?

[psafont]

I do prefer the name Interface.get_{positions,order,slots}, But I would keep the function separate, because they have different semantic meaning. was there only a single user of get_all?

[changlei-li]

Yes. There is only one single user of Net.Interface.get_all, which is xapi_pif.make_tables.

[psafont]

This will be user visible, might be worth explaining what that number is:

Suggested change

	let choose_network_name_for_pif device pos_opt =
	let pos_str =
	match pos_opt with None -> "" | Some pos -> Printf.sprintf "[%d]" pos
	in
	Printf.sprintf "Pool-wide network associated with %s%s" device pos_str
	let choose_network_name_for_pif device pos_opt =
	let pos_str =
	match pos_opt with None -> "" | Some pos -> Printf.sprintf "(slot %d)" pos
	in
	Printf.sprintf "Pool-wide network associated with %s %s" device pos_str

Does this rename the existing PIFs? we probably should start picking words for the user-visible concepts, so "slot" might not be the right one.

[changlei-li]

It's just the name label of network, not the PIF. It's all right to add slot to show its meaning explicitly.
@minglumlu I come up with a new question here that if we should change the name of network in xs8? I want to change it with adding slot x. I think no one will/should rely on network name label.

[minglumlu]

The word used in XenCenter is NIC. They could be consistent now.
Yeah, I think the name is only a default one. A user can change it later anyway.

[minglumlu]

Or in XS 8, the the networkd could not return the positions (hence dropping the get_index_from_ethx and sort_based_on_ethx) to keep the original naming of network.

[changlei-li]

The current solution is designed to limit the compatibility in networkd. We don't want to check and write two logics in xapi_pif again like networkd does. So, it's better to keep the main changes of get position method in networkd. If there is really a particular corner demand like the network name label to keep unchanged. I think it is ok to check and write two logics about it then.

[minglumlu]

That's why the position is of int option.

[changlei-li]

option here is mainly for ibft and non-physical devices.

[psafont]

The changes look good, but the commits need to be squashed, there are too many of them

[changlei-li]

The changes look good, but the commits need to be squashed, there are too many of them

Yes, of course. I have planned to do it before merge.

---

Done. Compare the diffs:

git diff 2acf27139 ac02a4a5d > diff.0
git diff 2acf27139 dbd1a3ed0 > diff.1
diff diff.0 diff.1

=> They are identical.