Use disk images instead of a rootfs tarball

scripts/anbox-init.sh

@@ -23,34 +23,6 @@ function prepare_filesystem() {
 		chown system:system /dev/$f
 		chmod 0666 /dev/$f
 	done
-
-	if [ ! -e /.anbox_setup_done ] ; then
-		echo "Fixing up all permissions ..."
-
-		# Fixup permissions of the android binaries in /system
-		while read line
-		do
-			file=`echo $line | cut -d' ' -f 1`
-			user=`echo $line | cut -d' ' -f 2`
-			group=`echo $line | cut -d' ' -f 3`
-			mode=`echo $line | cut -d' ' -f 4`
-			# Avoid changing symlinks
-			if [ ! -h /$file ] ; then
-				chmod $mode /$file
-				chown -h $user:$group /$file
-			fi
-		done < "/filesystem_config.txt"
-
-		# Additional ones not listed in the config generated from the build
-		for f in qemu_pipe qemu_trace goldfish_pipe ; do
-			[ ! -e /dev/$f ] && continue
-			chown system:system /dev/$f
-			chmod 0666 /dev/$f
-		done
-
-		echo "Setup done!"
-		echo $VERSION > /.anbox_setup_done
-	fi
 }
 
 prepare_filesystem &

scripts/container-manager.sh

@@ -5,18 +5,42 @@
 # Other than that nothing should ever modify the content of the
 # rootfs.
 
-ROOTFS_PATH=$SNAP_COMMON/var/lib/anbox/rootfs
-ROOTFS_VERSION=1
+DATA_PATH=$SNAP_COMMON/var/lib/anbox
+ROOTFS_PATH=$DATA_PATH/rootfs
+RAMDISK_PATH=$DATA_PATH/ramdisk
+INITRD=$SNAP/ramdisk.img
+SYSTEM_IMG=$SNAP/system.img
+ANDROID_DATA_PATH=$DATA_PATH/android-data
 
-if [ ! -e $ROOTFS_PATH ] || [ "$ROOTFS_VERSION" != "$(cat $ROOTFS_PATH/.version)" ] ; then
-	rm -rf $ROOTFS_PATH
-	echo "Copying rootfs into $ROOTFS_PATH .."
-	mkdir -p $ROOTFS_PATH
-	tar xf $SNAP/android-rootfs.tar -C $ROOTFS_PATH/ --strip-components=1
-	chown -R root:root $ROOTFS_PATH
-	echo $ROOTFS_VERSION > $ROOTFS_PATH/.version
+if [ ! -e $INITRD ]; then
+	echo "ERROR: boot ramdisk does not exist"
+	exit 1
 fi
 
+if [ ! -e $SYSTEM_IMG ]; then
+	echo "ERROR: system image does not exist"
+	exit 1
+fi
+
+# Extract ramdisk content instead of trying to bind mount the
+# cpio image file to allow modifications.
+rm -Rf $RAMDISK_PATH
+mkdir -p $RAMDISK_PATH
+cd $RAMDISK_PATH
+cat $INITRD | gzip -d | cpio -i
+
+# FIXME those things should be fixed in the build process
+chmod +x $RAMDISK_PATH/anbox-init.sh
+
+# Setup the read-only rootfs
+mkdir -p $ROOTFS_PATH
+mount -o bind,ro $RAMDISK_PATH $ROOTFS_PATH
+mount -o loop,ro $SYSTEM_IMG $ROOTFS_PATH/system
+
+# ... but we keep /data in the read/write space
+mkdir -p $ANDROID_DATA_PATH
+mount -o bind $ANDROID_DATA_PATH $ROOTFS_PATH/data
+
 # Make sure our setup path for the container rootfs
 # is present as lxc is statically configured for
 # this path.
@@ -31,3 +55,6 @@ pid=$!
 waitpid $pid
 
 $SNAP/bin/anbox-bridge.sh stop
+
+umount $ROOTFS_PATH/system
+umount $ROOTFS_PATH/data

snapcraft.yaml

@@ -22,11 +22,12 @@ apps:
 #    daemon: oneshot
 
 parts:
-  android-rootfs:
+  android:
     plugin: copy
     source: .
     files:
-      android-rootfs.tar: android-rootfs.tar
+      system.img: system.img
+      ramdisk.img: ramdisk.img
   anbox-common:
     plugin: copy
     source: .