Switch from raw images to qcow2 format

This allows to use minimal copy-on-write clones of the base image as
guest images, which in turn saves a lot of disk space.

testing/scripts/build-baseimage

@@ -10,6 +10,7 @@ echo "Building base image"
 EXTRAS=build-essential,gperf,libgmp-dev,libldap2-dev,libcurl4-openssl-dev,libxml2-dev,libtspi-dev,libsqlite3-dev,openssh-server,tcpdump,psmisc,openssl,vim,sqlite3,conntrack,gdb,cmake,libxerces-c2-dev,libltdl-dev,liblog4cxx10-dev,libboost-thread-dev,libboost-system-dev,git-core
 SERVICES="isc-dhcp-server apache2 slapd"
 PACKAGES=$EXTRAS,${SERVICES// /,}
+
 CACHEDIR=$BUILDDIR/cache
 APTCACHE=$LOOPDIR/var/cache/apt/archives
 
@@ -19,28 +20,45 @@ mkdir -p $CACHEDIR
 rm -f $ROOTFS
 
 echo "`date`, building $ROOTFS" >>$LOGFILE
+
+load_qemu_nbd
+
 log_action "Creating image $ROOTFS"
-execute "dd if=/dev/null of=$ROOTFS bs=1M seek=$ROOTFSSIZE count=1"
+execute "qemu-img create -f qcow2 $ROOTFS ${ROOTFSSIZE}M"
+
+log_action "Connecting image to NBD device $NBDEV"
+execute "qemu-nbd -c $NBDEV $ROOTFS"
+sync
+
+log_action "Partitioning disk"
+sfdisk /dev/nbd0 -D -uM >>$LOGFILE 2>&1 << EOF
+;
+EOF
+if [ $? != 0 ]
+then
+	log_status 1
+	exit 1
+else
+	log_status 0
+fi
 
 log_action "Creating ext3 filesystem"
-execute "mkfs.ext3 -F $ROOTFS"
+execute "mkfs.ext3 $NBDPARTITION"
 
-log_action "Mounting image to $LOOPDIR"
-execute "mount -o loop $ROOTFS $LOOPDIR"
+log_action "Mounting $NBDPARTITION to $LOOPDIR"
+execute "mount $NBDPARTITION $LOOPDIR"
 
-log_action "Mounting cache to $CACHEDIR"
+log_action "Using $CACHEDIR as archive for apt"
 mkdir -p $APTCACHE
 execute "mount -o bind $CACHEDIR $APTCACHE"
 
-do_on_exit umount -l $APTCACHE
-do_on_exit umount -l $LOOPDIR
+do_on_exit graceful_umount $APTCACHE
+do_on_exit graceful_umount $LOOPDIR
+do_on_exit qemu-nbd -d $NBDEV
 
 log_action "Running debootstrap ($ROOTFSSUITE, $ROOTFSARCH)"
 execute "debootstrap --arch=$ROOTFSARCH --include=$PACKAGES $ROOTFSSUITE $LOOPDIR $ROOTFSMIRROR"
 
-log_action "Disabling root password"
-execute_chroot "passwd -d root"
-
 for service in $SERVICES
 do
 	log_action "Stopping service $service"
@@ -48,3 +66,6 @@ do
 	log_action "Disabling service $service"
 	execute_chroot "update-rc.d -f $service remove"
 done
+
+log_action "Disabling root password"
+execute_chroot "passwd -d root"

testing/scripts/build-umlhostfs

@@ -1,5 +1,5 @@
 #!/bin/bash
-# create UML host file systems
+# create specific guest images
 #
 # Copyright (C) 2004  Eric Marchionni, Patrik Rayo
 # Zuercher Hochschule Winterthur
@@ -20,12 +20,14 @@ echo "Creating guest images"
 
 [ `id -u` -eq 0 ] || die "You must be root to run $0"
 
-BASE=$BUILDDIR/base.img
+BASE=$BUILDDIR/base.qcow2
 HOSTSDIR=$PWD/hosts
 
 [ -f $BASE ] || die "Base image $BASE not found"
 [ -f $HOSTDIR ] || die "Hosts directory $HOSTSDIR not found"
 
+load_qemu_nbd
+
 mkdir -p $BUILDDIR
 mkdir -p $LOOPDIR
 
@@ -41,8 +43,10 @@ do_on_exit umount $LOOPDIR
 for host in $HOSTS
 do
 	log_action "Creating guest image for $host"
-	execute "cp $BASE $ROOTFSDIR/$host.img" 0
-	execute "mount -o loop $ROOTFSDIR/$host.img $LOOPDIR" 0
+	execute "qemu-img create -b $BASE -f qcow2 $ROOTFSDIR/$host.qcow2" 0
+	execute "qemu-nbd -c $NBDEV $ROOTFSDIR/$host.qcow2" 0
+	sync
+	execute "mount $NBDPARTITION $LOOPDIR" 0
 	execute "cp -rf $HOSTSDIR/${host}/etc $LOOPDIR" 0
 	execute "cp -rf $HOSTSDIR/default/etc $LOOPDIR" 0
 	if [ "$host" = "winnetou" ]
@@ -58,6 +62,7 @@ do
 		execute_chroot "chown -R openldap:openldap /var/lib/ldap" 0
 	fi
 	sync
+	execute "umount $LOOPDIR" 0
+	execute "qemu-nbd -d $NBDEV" 0
 	log_status 0
-	umount $LOOPDIR
 done

testing/scripts/build-umlrootfs

@@ -1,5 +1,5 @@
 #!/bin/bash
-# Create UML root filesystem
+# Create guest root image
 #
 # Copyright (C) 2004  Eric Marchionni, Patrik Rayo
 # Zuercher Hochschule Winterthur
@@ -22,17 +22,24 @@ echo "Building root image"
 
 [ -f "$ROOTFS" ] || die "Root image $ROOTFS not found"
 
+load_qemu_nbd
+
 mkdir -p $ROOTFSDIR
 mkdir -p $LOOPDIR
 mkdir -p $ROOTFSCOMPILEDIR
 cd $ROOTFSDIR
 
-BASE=$BUILDDIR/base.img
+BASE=$BUILDDIR/base.qcow2
 log_action "Creating $BASE"
 execute "cp $ROOTFS $BASE"
 
-log_action "Mounting base image $BASE"
-execute "mount -o loop $BASE $LOOPDIR"
+log_action "Connecting base image to NBD device $NBDEV"
+execute "qemu-nbd -c $NBDEV $BASE"
+sync
+
+log_action "Mounting $NBDPARTITION to $LOOPDIR"
+execute "mount $NBDPARTITION $LOOPDIR"
+
 log_action "Mounting proc filesystem to $LOOPDIR/proc"
 execute "mount -t proc none $LOOPDIR/proc"
 
@@ -43,6 +50,7 @@ execute "mount -o bind $ROOTFSCOMPILEDIR $LOOPDIR/root/compile"
 do_on_exit umount $LOOPDIR/root/compile
 do_on_exit umount $LOOPDIR/proc
 do_on_exit umount $LOOPDIR
+do_on_exit qemu-nbd -d $NBDEV
 
 echo "Installing software from source"
 RECPDIR=$TESTDIR/testing/scripts/recipes

testing/scripts/function.sh

@@ -117,6 +117,37 @@ do_on_exit()
 	fi
 }
 
+# wait for a mount to disappear
+# $1 - device/image to wait for
+# $2 - maximum time to wait in seconds, default is 5 seconds
+graceful_umount()
+{
+	secs=$2
+	[ ! $secs ] && secs=5
+
+	let steps=$secs*100
+	for i in `seq 1 $steps`
+	do
+		umount $1 >>$LOGFILE 2>&1
+		mount | grep $1 >/dev/null 2>&1
+		[ $? -eq 0 ] || return 0
+		sleep 0.01
+	done
+
+	return 1
+}
+
+# load qemu NBD kernel module, if not already loaded
+load_qemu_nbd()
+{
+	lsmod | grep ^nbd[[:space:]]* >/dev/null 2>&1
+	if [ $? != 0 ]
+	then
+		log_action "Loading NBD kernel module"
+		execute "modprobe nbd max_part=16"
+	fi
+}
+
 #############################################
 # search and replace strings throughout a
 # whole directory