Backport the 999-ubuntu-image-customization changes, add a delta on top to still support the old legacy raspi2 images.

debian/changelog

@@ -2,8 +2,11 @@ livecd-rootfs (2.525.32) UNRELEASED; urgency=medium
 
   * Fix a terrible typo in auto/build that causes all core18 builds to fail on
     this series (LP: #1849343).
+  * Backport 999-ubuntu-image-customization.chroot to have a common place for
+    our cloud-init datasource.  Add some modifications on top to make sure the
+    legacy raspi2 configuration stays the same.  (LP: #1849472)
 
- -- Łukasz 'sil2100' Zemczak <lukasz.zemczak@ubuntu.com>  Tue, 22 Oct 2019 17:09:57 +0200
+ -- Łukasz 'sil2100' Zemczak <lukasz.zemczak@ubuntu.com>  Tue, 22 Oct 2019 17:34:31 +0200
 
 livecd-rootfs (2.525.31) bionic; urgency=medium
 

live-build/auto/config

@@ -930,6 +930,8 @@ echo "LB_BINARY_HOOKS=\"$BINARY_HOOKS\"" >> config/binary
 echo "BUILDSTAMP=\"$NOW\"" >> config/binary
 echo "SUBPROJECT=\"${SUBPROJECT:-}\"" >> config/binary
 echo "LB_DISTRIBUTION=\"$SUITE\"" >> config/binary
+echo "IMAGEFORMAT=\"$IMAGEFORMAT\"" >> config/chroot
+echo "SUBARCH=\"$SUBARCH\"" >> config/chroot
 
 case $ARCH+$SUBARCH in
 	armhf+raspi2|armhf+raspi3|arm64+raspi3)

live-build/ubuntu-cpc/hooks.d/chroot/999-cpc-fixes.chroot

@@ -142,22 +142,17 @@ fi
 #### END COMMON ARCH FUNCTIONS
 
 
-case $arch in
-	# ARM images are special
-	armhf|arm64)
-		# Dirty hack because SUBARCH doesn't exist when running chroot hooks,
-		# and we don't want raspi2 images to depend on a cloud data source:
-		if _xchroot "${rootd}" dpkg -l linux-image-raspi2 2>/dev/null | grep -q '^.i'; then
-			fake_cloud_init
-		fi
-
-		echo "Image architecture is ARM. Existing vmbuilder-fixups"
-
-		exit 0
-		;;
-	powerpc|ppc64el|s390x)
-		exit 0
-		;;
+case $arch+${SUBARCH:-} in
+    # raspi2 images are special
+    armhf+raspi2)
+        fake_cloud_init
+        echo "Image architecture is ARM. Existing vmbuilder-fixups"
+        exit 0
+        ;;
+
+    armhf+*|arm64+*|powerpc+*|ppc64el+*|s390x+*)
+        exit 0
+        ;;
 esac
 
 psuedo_grub_probe() {

live-build/ubuntu-cpc/hooks.d/chroot/999-ubuntu-image-customization.chroot

@@ -0,0 +1,23 @@
+#!/bin/bash -ex
+
+. /root/config/chroot
+
+# Specific ubuntu-image chroot configuration goes here.
+# Currently the none IMAGEFORMAT is equivalent to building a rootfs for an image
+# for a physical device, not a cloud instance. For such images we want some
+# special cloud-init configuration that should not be happening for cloud
+# cases. This check should be changed to a per-MODEL/per-SUBARCH check once
+# we support building cloud images via ubuntu-image.
+if [ "$IMAGEFORMAT" == "none" ]; then
+    # If the cloud does not provide a meta-data service this should be run
+    # This will setup a nocloud datasource on the boot partition.
+    # This is the default behavior for our ubuntu-image built preinstalled
+    # images.
+    cat << EOF > /etc/cloud/cloud.cfg.d/99-fake_cloud.cfg
+# configure cloud-init for NoCloud
+datasource_list: [ NoCloud, None ]
+datasource:
+  NoCloud:
+    fs_label: system-boot
+EOF
+fi