I recently pulled initramfs logic out of the base build hook, and
dropped that into the `replace_kernel` function. Any cloud image that
does not leverage the generic virtual kernel was expected to call
`replace_kernel` to pull in a custom kernel. That function will
disable initramfs boot for images that use a custom kernel.
Minimal cloud images on amd64 use the linux-kvm kernel, but the build
hook does not utilize the `replace_kernel` function. Instead, the
kernel flavor is set in `auto/config`. I pulled that logic out of
`auto/config` and am now calling `replace_kernel` in the build hook.
I also moved a call to generate the package list so that it will pick
up the change to the linux-kvm kernel.
With this change, when we attempt to boot with an initramfs and fail,
initrdless_boot_fallback_triggered is set to non-zero in the grubenv.
This value can be checked after boot by looking in /boot/grub/grubenv
or by using the grub-editenv list command.
Addresses LP: #1870189
Generic cloud images with the linux-generic kernel are not able to
boot without an initramfs. Previously, these images attempted to boot
without an initramfs, would fail, and then retry with an initramfs.
This slows the boot and is confusing behavior.
shim-signed depends on grub-efi-amd64-signed, which in turn has
alternative depends on either `grub-efi-amd64 | grub-pc`. However to
support booting with either via shim&signed-grub and BIOS, the choice
must be made to install grub-pc, not grub-efi-amd64.
This makes images consistent with Ubuntu Deskop, Live Server, buildd
bootable images; all of which already do install grub-pc and
shim-signed.
Additionally, this will ensure that autoremove is run after installing
anything in the CPC build hooks. This is done to avoid shipping images
that include packages that are autoremovable. This will clean-up as
packages are installed and detect any breakage at build time.
LP: #1901906
This patch currently only applies to the "ubuntu-cpc" project.
More and more logic has been going into the hook scripts to decide under which conditions they should run or not. As we are moving to parallelized builds of image sets, this will get even more complicated. Base hooks will have to know which image sets they belong to and modification of the dependency chain between scripts will become more complicated and prone to errors, as the number of image sets grows.
This patch introduces explicit ordering and dependency handling for scripts through the use of `series` files and an explicit syntax for dependency specification.
