Support generating a .disk/info file via ubuntu-image.

debian/changelog

@@ -1,3 +1,10 @@
+livecd-rootfs (2.525.38) UNRELEASED; urgency=medium
+
+  * Support generating a .disk/info file via ubuntu-image from the passed-in
+    datestamp parameter (using the $NOW environment variable). (LP: #1856684)
+
+ -- Łukasz 'sil2100' Zemczak <lukasz.zemczak@ubuntu.com>  Wed, 22 Jan 2020 09:18:06 +0100
+
 livecd-rootfs (2.525.37) bionic; urgency=medium
 
   * Use the raspi2-hwe-18.04-edge kernel flavour for the raspi3 images. This

live-build/auto/config

@@ -196,13 +196,20 @@ case $IMAGEFORMAT in
 				;;
 		esac
 
+		# If we have a datestamp coming from cdimage, use that to populate
+		# .disk/info on the target image
+		if [ -n "$NOW" ]; then
+			echo "$NOW" > config/disk-info
+			UBUNTU_IMAGE_ARGS="$UBUNTU_IMAGE_ARGS --disk-info config/disk-info"
+		fi
+
 		if [ $PROJECT = "ubuntu-core" ]; then
 			# snap-based core images
 
 			case $MODEL in
 				pc-amd64|pc-i386)
 					[ -z "${SUBARCH:-}" ] \
-					&& UBUNTU_IMAGE_ARGS="--image-size 3700M"
+					&& UBUNTU_IMAGE_ARGS="$UBUNTU_IMAGE_ARGS --image-size 3700M"
 					;;
 			esac
 			case $SUITE in