with canary image, plaintext install gets linux-generic instead of linux-generic-hwe-22.04

[Steve Langasek]

After install with the 20230825.2 canary image a classic install (no tpm fde) has linux-generic installed, whereas an install using daily-live 20230825 gets linux-generic-hwe-22.04.

This may be due to a difference in debian-cd, and the two different installer images booting a different kernel.

[Michael Hudson-Doyle (mwhudson)]

Two parts to this:

1) We should add_package linux-generic-hwe-$LTS in the canary) section of auto/config
2) We should add a file called /etc/subiquity/kernel-meta-package containing the name of the kernel metapackage to use to the live layer.

[Steve Langasek (vorlon)]

> 1) We should add_package linux-generic-hwe-$LTS in the canary) section of auto/config

Under the non-canary section this is currently written as:

                                KERNEL_FLAVOURS='generic-hwe-22.04'

Having a poke to understand if that's sufficient or not.

[Steve Langasek (vorlon)]

We currently install the linux kernel in the standard.live layer. It looks to me like KERNEL_FLAVOURS='generic-hwe-22.04' in canary, rather than an explicit add_package, should DTRT here.

> 2) We should add a file called /etc/subiquity/kernel-meta-package containing
> the name of the kernel metapackage to use to the live layer.

It doesn't appear we currently do this in any other images. I'm assuming this is necessary because unlike the current daily-live image, the canary image installs the kernel in the live layer and not in the standard layer and therefore it's not part of the rootfs that we copy from.

However, in terms of the installer flow I wonder if it wouldn't be better to put the kernel in the standard layer, being the layer that is used as the installation source, and to then have the standard.enhanced-secureboot layer remove the kernel deb? This should save us from having to do an explicit apt install of the kernel as part of the installation, saving on install time for the classic case.

[Jean-Baptiste Lallement (jibel)]

With u-d-i 1215 is it now trying to install the correct kernel but failing because it is not on the iso.

[Dan Bungert (dbungert)]

Via /run/kernel-meta-package, the requested kernel is linux-generic-hwe-22.04. This file is populated by way of casper hooks.

With https://code.launchpad.net/~dbungert/ubuntu-seeds/+git/ubuntu/+merge/450177, this kernel will be added to canary-ship-live, (that MP also removes all remaining functional differences between ship-live and canary-ship-live).

Modifying an ISO to have this kernel in the pool allows the install to complete.

[Dan Bungert (dbungert)]

Seed change merged, please retest in Aug-30 iso rebuild

[Steve Langasek (vorlon)]

confirmed fixed with 20230830.