Add config-changed openstack upgrade support.

hooks/config-changed

@@ -0,0 +1 @@
+swift-storage-node-relations

hooks/swift-storage-node-common

@@ -129,3 +129,22 @@ function setup_storage {
   done
   chown -R swift:swift /srv/node
 }
+
+function do_openstack_upgrade {
+  # update openstack components to those provided by a new installation source
+  # it is assumed the calling hook has confirmed that the upgrade is sane.
+  local rel="$1"
+  shift
+  local packages=$@
+
+  # Backup the config directory.
+  local stamp=$(date +"%Y%m%d%M%S")
+  tar -pcf /var/lib/juju/$CHARM-backup-$stamp.tar $CONF_DIR
+
+  configure_install_source "$rel"
+  apt-get update
+  DEBIAN_FRONTEND=noninteractive apt-get \
+     --option Dpkg::Options::=--force-confnew -y \
+     install --no-install-recommends $packages
+  swift-init all restart || true
+}

hooks/swift-storage-node-relations

@@ -67,9 +67,23 @@ function storage_changed {
   swift-init all start || true
 }
 
+function config_changed {
+  local install_src=$(config-get openstack-origin)
+  local cur=$(get_os_codename_package "glance-common")
+  local available=$(get_os_codename_install_source "$install_src")
+  if [[ "$available" != "unknown" ]] ; then
+    if dpkg --compare-versions $(get_os_version_codename "$cur") lt \
+                               $(get_os_version_codename "$available") ; then
+      juju-log "$CHARM: Upgrading OpenStack release: $cur -> $available."
+      do_openstack_upgrade "$install_src" $PACKAGES
+    fi
+  fi
+}
+
 case $ARG0 in
   "install") install_hook ;;
   "start"|"stop") exit 0 ;;
   "swift-storage-relation-joined") storage_joined ;;
   "swift-storage-relation-changed") storage_changed ;;
+  "config-changed") config_changed ;;
 esac