Open Stack

> So say the user requests a node that supports UEFI because their image
> needs UEFI. Which workflow would you want here?
> 
> 1) The operator (or ironic?) has already configured the node to boot in
> UEFI mode. Only pre-configured nodes advertise the "supports UEFI" trait.
> 
> 2) Any node that supports UEFI mode advertises the trait. Ironic ensures
> that UEFI mode is enabled before provisioning the machine.
> 
> I imagine doing #2 by passing the traits which were specifically
> requested by the user, from Nova to Ironic, so that Ironic can do the
> right thing for the user.
> 
> Your proposal suggests that the user request the "supports UEFI" trait,
> and *also* pass some glance UUID which the user understands will make
> sure the node actually boots in UEFI mode. Something like:
> 
> openstack server create --flavor METAL_12CPU_128G --trait SUPPORTS_UEFI
> --config-data $TURN_ON_UEFI_UUID
> 
> Note that I pass --trait because I hope that will one day be supported
> and we can slow down the flavor explosion.

IMO --trait would be making things worse (but see below). I think UEFI
with Jay's model would be more like:

  openstack server create --flavor METAL_12CPU_128G --config-data $UEFI

where the UEFI profile would be pretty trivial, consisting of
placement.traits.required = ["BOOT_MODE_UEFI"] and object.boot_mode =
"uefi".

I agree that this seems kind of heavy, and that it would be nice to be
able to say "boot mode is UEFI" just once. OTOH I get Jay's point that
we need to separate the placement decision from the instance configuration.

That said, what if it was:

 openstack config-profile create --name BOOT_MODE_UEFI --json -
 {
  "type": "boot_mode_scheme",
  "version": 123,
  "object": {
      "boot_mode": "uefi"
  },
  "placement": {
   "traits": {
    "required": [
     "BOOT_MODE_UEFI"
    ]
   }
  }
 }
 ^D

And now you could in fact say

 openstack server create --flavor foo --config-profile BOOT_MODE_UEFI

using the profile name, which happens to be the same as the trait name
because you made it so. Does that satisfy the yen for saying it once? (I
mean, despite the fact that you first had to say it three times to get
it set up.)

========

I do want to zoom out a bit and point out that we're talking about
implementing a new framework of substantial size and impact when the
original proposal - using the trait for both - would just work out of
the box today with no changes in either API. Is it really worth it?

========

By the way, with Jim's --trait suggestion, this:

> ...dozens of flavors that look like this:
> - 12CPU_128G_RAID10_DRIVE_LAYOUT_X
> - 12CPU_128G_RAID5_DRIVE_LAYOUT_X
> - 12CPU_128G_RAID01_DRIVE_LAYOUT_X
> - 12CPU_128G_RAID10_DRIVE_LAYOUT_Y
> - 12CPU_128G_RAID5_DRIVE_LAYOUT_Y
> - 12CPU_128G_RAID01_DRIVE_LAYOUT_Y

...could actually become:

 openstack server create --flavor 12CPU_128G --trait $WHICH_RAID --trait
$WHICH_LAYOUT

No flavor explosion.

(Maybe if we called it something other than --trait, like maybe
--config-option, it would let us pretend we're not really overloading a
trait to do config - it's just a coincidence that the config option has
the same name as the trait it causes to be required.)

-efried
.