Backport two minimizations for the docker images: remove apt lists that are removed downstream anyway, and remove device nodes from the image. (LP: #1828118)

debian/changelog

@@ -1,3 +1,11 @@
+livecd-rootfs (2.525.23) UNRELEASED; urgency=medium
+
+  * Backport two minimizations for the docker images: remove apt lists that
+    are removed downstream anyway, and remove device nodes from the image.
+    (LP: #1828118)
+
+ -- Michael Hudson-Doyle <michael.hudson@ubuntu.com>  Wed, 08 May 2019 10:48:39 +1200
+
 livecd-rootfs (2.525.22) bionic; urgency=medium
 
   * Subiquity specific changes SRU LP: #1827357

live-build/auto/build

@@ -436,6 +436,17 @@ EOF
 	# remove crufty files that shouldn't be left in an image
 	rm -f chroot/var/cache/debconf/*-old chroot/var/lib/dpkg/*-old
 	Chroot chroot apt clean
+	# For the docker images we remove even more stuff.
+	if [ "${PROJECT}:${SUBPROJECT:-}" = "ubuntu-base:minimized" ]; then
+		# Remove apt lists (that are currently removed downstream
+		# anyway)
+		rm -rf chroot/var/lib/apt/lists/*
+		# Having device nodes in the docker image can cause problems
+		# (https://github.com/tianon/docker-brew-ubuntu-core/issues/62)
+		# so remove them.  We only do this for docker out of an
+		# abundance of caution.
+		rm -rf chroot/dev/*
+	fi
 
 	lb binary "$@"
 	touch binary.success