Make use of XenStore to export SUCCESS msg

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>

snf-image-helper/common.sh

@@ -420,6 +420,21 @@ check_if_excluded() {
     return 0
 }
 
+
+return_success() {
+
+    case $hypervisor in
+      kvm)
+        echo "SUCCESS" > "$RESULT"
+        ;;
+      xen-pvm|xen-kvm)
+        domid=$(xenstore-read domid)
+        xenstore-write /local/domain/0/helper/$domid SUCCESS
+        ;;
+    esac
+
+}
+
 trap cleanup EXIT
 set -o pipefail
 

snf-image-helper/snf-image-helper.in

@@ -97,7 +97,7 @@ fi
 # Disable the trap. If code reaches here, the filesystem is unmounted.
 trap - ERR
 
-echo "SUCCESS" > "$RESULT"
+return_success
 
 cleanup
 trap - EXIT

snf-image-host/common.sh.in

@@ -388,7 +388,7 @@ fi
 : ${HELPER_USER:="nobody"}
 : ${HELPER_CACHE_FILE:="@HELPER_DIR@/cache.tar"}
 : ${HELPER_CACHE_PKGS:="@HELPER_DIR@/packages"}
-: ${HELPER_EXTRA_PKGS:="e2fsprogs,ntfs-3g,ntfsprogs,xmlstarlet,python,parted,reglookup,chntpw,util-linux"}
+: ${HELPER_EXTRA_PKGS:="xenstore-utils,e2fsprogs,ntfs-3g,ntfsprogs,xmlstarlet,python,parted,reglookup,chntpw,util-linux"}
 : ${HELPER_LINUX_IMAGE_PKG:="linux-image-amd64"}
 : ${HELPER_LINUX_IMAGE_XEN_PKG:="linux-image-xen-amd64"}
 : ${HELPER_MIRROR:=""}

snf-image-host/defaults

@@ -53,7 +53,7 @@
 # HELPER_EXTRA_PKGS: Extra packages that will need to be supplied
 # to debootstrap to make the resulting helper image workable.
 # DO NOT OVERWRITE THIS UNLESS YOU KNOW WHAT YOU ARE DOING
-# HELPER_EXTRA_PKGS="e2fsprogs,ntfs-3g,ntfsprogs,xmlstarlet,python,parted,reglookup,chntpw,util-linux"
+# HELPER_EXTRA_PKGS="xenstore-utils,e2fsprogs,ntfs-3g,ntfsprogs,xmlstarlet,python,parted,reglookup,chntpw,util-linux"
 # HELPER_LINUX_IMAGE_PKG="linux-image-amd64"
 # HELPER_LINUX_XEN_IMAGE_PKG="linux-image-xen-amd64"
 

snf-image-host/snf-image-update-helper.in

@@ -289,6 +289,9 @@ else
             ;;
         esac
     done
+    case \$hypervisor in
+        xen-pvm|xen-kvm) mount -t xenfs xenfs /proc/xen ;;
+    esac
     /usr/bin/snf-image-helper --force
 fi
 

snf-image-host/xen-common.sh

@@ -9,20 +9,31 @@ mk_snapshot() {
 }
 
 launch_helper() {
+
+    helper_name=helper$$
+    xm create /dev/null \
+      kernel="$HELPER_KERNEL" ramdisk="$HELPER_INITRD" \
+      disk="file:$snapshot,xvda,w" \
+      disk="phy:$blockdev,xvdb,w" \
+      disk="file:$floppy,xvdc1,w" \
+      extra="console=hvc0 hypervisor=$HYPERVISOR snf_image_activate_helper" \
+      memory="256" root="/dev/xvda1 quiet ro boot=local" boot="c" vcpus=1 \
+      name="$helper_name"
+
+    if ! xenstore-exists helper;
+        xenstore-write helper ""
+    fi
+    helperid=$(xm domid $helper_name)
+    xenstore-write helper/$helperid ""
+    xenstore-chmod helper/$helperid r0 w$helperid
+
     tail -f --pid=$$ "$result_file" | sed -u 's|^|HELPER: |' &
     $TIMEOUT -k $HELPER_HARD_TIMEOUT $HELPER_SOFT_TIMEOUT \
-      screen -D -m -c /etc/screenrc bash -c 'xm create /dev/null \
-      kernel="'$HELPER_KERNEL'" ramdisk="'$HELPER_INITRD'" \
-      disk="file:'$snapshot',xvda,w" \
-      disk="phy:'$blockdev',xvdb,w" \
-      disk="file:'$floppy',xvdc1,w" \
-      extra="console=hvc0 hypervisor='$HYPERVISOR' snf_image_activate_helper" \
-      memory="256" root="/dev/xvda1 quiet ro boot=local" boot="c" vcpus=1 \
-      name="snf-image-helper" -c > '$result_file''
+      screen -D -m -c /etc/screenrc bash -c ' xm console '$helper_name' > '$result_file''
 }
 
 get_helper_result() {
 
-    result=$(sed 's|\r||g' "$result_file" | grep ^SUCCESS$)
+    result=$(xenstore-read helper/$helperid)
 
 }