Choose existing disk as a boot disk on instance create

[smklein]

... but I should be able to, right?

Steps to repro:

• Create an instance, use an existing image as the disk of choice (I used debian, you can use whatever)
• Observe the disk and instance exist
• Stop the instance, delete it
• Observe the boot disk still exists
• Try to create a new instance using the old boot disk
• Observe that "boot disk" requires one of "{distros, images, snapshots}". Old boot disks do not show up here. Notably it can be attached as an "additional disk", but not as an old boot disk.

[smklein]

FWIW I consider this relatively low-priority, but wanted to flag it regardless.

[zephraph]

Yeah, we're aware of this. It's relatively low priority in the sense of UI functionality, but it's technically rather easy to accommodate. Boot disk creation / configuration is still the area that needs the most work in instance creation.

[zephraph]

I've pushed this issue off to the next milestone. The UI pattern for implementing this feature exists but there's a bit of a larger question around data. Ultimately this relies on the disks list endpoint but will need to be filtered down to unattached disks.

Currently the notion of filtering doesn't exist in our API. We'd need to figure out a way of requesting unattached disks. That could be /disks/unattached or /disks?instance_id=null... something like that. Idk, we'll need to figure it out.

[david-crespo]

How important is API support @zephraph? Could we fudge it by filtering on the client?

[zephraph]

Potentially. @ahl wants to change the part of the instance create API around disks, images, etc so it could impact this.

[david-crespo]

The problem here is we always insert a created disk from the "boot disk" section as the first element in the list of disks. I think in order to solve this properly we need to rework these two sections so that we are not introducing an artificial concept of boot disk. We do have that concept in the API in that the first disk in the list is treated as the boot disk, but there is otherwise nothing special about it. The Boot Disk section of the form is a helper to make clear that you almost certainly want at least one disk attached to your instance so you can boot from it.

Maybe we can keep the boot disk section but add a kind of toggle that lets you choose between creating a new disk and attaching an existing one. The thing I don't like about that is that it duplicates the distinction we already make under additional disks between create and attach. Maybe that's fine.

console/app/forms/instance-create.tsx

Lines 196 to 212 in 0469280

	disks: [
	{
	type: 'create',
	// TODO: Determine the pattern of the default boot disk name
	name: bootDiskName,
	description: `Created as a boot disk for ${values.name}`,
	// Minimum size as greater than the image is validated
	// directly on the boot disk size input
	size: values.bootDiskSize * GiB,
	diskSource: {
	type: 'image',
	imageId: values.image,
	},
	},
	...values.disks,
	],

[benjaminleonard]

Can we just add "Disk" as a tab under boot disk. That way it's extendable and we can use snapshots in the future too. That tab can contain a listbox with all the disks (another motivation for #1942).

[david-crespo]

That’s just the kind of inside-the-box thinking we need.

[benjaminleonard]

I only occasionally suggest the most convoluted solution