Revert of initramfs package removal in KVM image (LP: #1880170)

It was reported and confirmed in LP bug #1875400
(https://bugs.launchpad.net/cloud-images/+bug/1875400) that on the public
KVM cloud image there exists a large list of packages marked for auto-removal.

This should never be the case on a released cloud image.

These packages are marked for auto-removal because in the KVM image binary hook
we removed both initramfs-tools and busybox-initramfs packages. Due to package
dependencies this also removed:

busybox-initramfs* cloud-initramfs-copymods* cloud-initramfs-dyn-netconf*
cryptsetup-initramfs* initramfs-tools* initramfs-tools-core* multipath-tools*
overlayroot* sg3-utils-udev* ubuntu-server*

But it did not remove all the packages that the above list depended on.
This resulted in all those packages being marked for auto-removal because they
were not manually installed nor did they have any manually installed packages
that depended on them.

The removal of initramfs-tools and busybox-initramfs was to avoid the
generation of initramfs in images that should boot initramfsless.

This requirement is obsolete now because the initramfsless boot handling
is now handled via setting GRUB_FORCE_PARTUUID in /etc/default/grub.d/40-force-partuuid.cfg.

In test images I have verified that GRUB_FORCE_PARTUUID is set and that
boot speeds have not regressed.

LP: #1880170

debian/changelog

@@ -1,3 +1,20 @@
+livecd-rootfs (2.664.2) focal; urgency=medium
+
+  * Revert of initramfs package removal in KVM image (LP: #1880170)
+
+ -- Phil Roche <phil.roche@canonical.com>  Fri, 22 May 2020 13:03:20 +0100
+
+livecd-rootfs (2.664.1) focal; urgency=medium
+
+  * Bump only the UC20 pc image to 8GB, and keep Pi images as small as possible.
+    (LP: #1875430)
+  * ubuntu-image: fix focal+ pi images for armhf to use pi-armhf model name.
+    (LP: #1876358)
+  * ubuntu-image: drop ubuntu-image dep on riscv64, as not installable yet.
+    (LP: #1876359)
+
+ -- Dimitri John Ledkov <xnox@ubuntu.com>  Fri, 01 May 2020 20:08:23 +0100
+
 livecd-rootfs (2.664) focal; urgency=medium
 
   [ Patrick Viafore ]

debian/control

@@ -38,7 +38,7 @@ Depends: ${misc:Depends},
          squashfs-tools (>= 1:3.3-1),
          sudo,
          u-boot-tools [armhf arm64],
-         ubuntu-image [!i386],
+         ubuntu-image [!i386 !riscv64],
          python3-vmdkstream [amd64 i386],
          xz-utils,
          zerofree

live-build/auto/config

@@ -359,8 +359,16 @@ case $IMAGEFORMAT in
 			CHANNEL="${CHANNEL:-edge}"
 			case $MODEL in
 				pc-amd64|pc-i386)
-					[ -z "${SUBARCH:-}" ] \
-					&& UBUNTU_IMAGE_ARGS="$UBUNTU_IMAGE_ARGS --image-size 3700M"
+					if [ -z "${SUBARCH:-}" ]; then
+						case $SUITE in
+							xenial|bionic)
+								UBUNTU_IMAGE_ARGS="$UBUNTU_IMAGE_ARGS --image-size 3700M"
+								;;
+							*)
+								UBUNTU_IMAGE_ARGS="$UBUNTU_IMAGE_ARGS --image-size 8G"
+								;;
+						esac
+					fi
 					;;
 				*) ;;
 			esac
@@ -375,7 +383,9 @@ case $IMAGEFORMAT in
 					UBUNTU_IMAGE_ARGS="$UBUNTU_IMAGE_ARGS -c $CHANNEL"
 					;;
 				*)
-					UBUNTU_IMAGE_ARGS="--image-size 10G"
+					if [ "${MODEL}" = "pi" ]; then
+						MODEL=pi-armhf
+					fi
 					# Ubuntu Core 20
 					# Currently uc20 assertions do not support global
 					# channel overrides, instead we have per-channel models

live-build/ubuntu-cpc/hooks.d/base/kvm-image.binary

@@ -49,10 +49,6 @@ replace_kernel ${mount_d} "linux-kvm"
 chroot "${mount_d}" update-grub
 undivert_grub "${mount_d}"
 
-# Remove initramfs for kvm image
-env DEBIAN_FRONTEND=noninteractive chroot "${mount_d}" apt-get \
-    purge -y initramfs-tools busybox-initramfs
-
 env DEBIAN_FRONTEND=noninteractive chroot "${mount_d}" rm \
     -rf /boot/initrd.img-* /boot/initrd.img