labs: fix shared folder restore after export

Fix the code responsible for reattaching shared directories after VMs
have been exported.

For OVA export:
- use saved share names instead of default name (for the sake of
  correctness; it is unlikely that a user will change the name)

For dir export:
- save and reattach shared directories after export

Change-Id: I79162c1ec788aa1d89104aa92aebeae2bb05adf5

labs/lib/osbash/virtualbox.functions

@@ -410,7 +410,7 @@ function vm_export_ova {
     local ii=0
     for node in $nodes; do
         if [ -n "${share_paths[$ii]}" ]; then
-            vm_add_share "$node" "$SHARE_DIR" "$SHARE_NAME"
+            vm_add_share "$node" "${share_paths[$ii]}" "$SHARE_NAME"
         fi
         ii=$(($ii + 1))
     done
@@ -430,7 +430,11 @@ function vm_export_dir {
             $VBM controlvm "$node" poweroff
         fi
         sleep 1
+        local share_path=$(vm_get_share_path "$node")
+        if [ -n "$share_path" ]; then
+            echo >&2 "Removing shared folder for export"
             vm_rm_share "$node" "$SHARE_NAME"
+        fi
         sleep 1
         echo "Exporting VM $node to $export_dir"
         # Use all: machineandchildren works only if --snapshot is given as UUID
@@ -440,6 +444,10 @@ function vm_export_dir {
             --name "$node" \
             --groups "/$VM_GROUP" \
             --basefolder "$export_dir"
+        if [ -n "$share_path" ]; then
+            echo >&2 "Reattaching shared folder"
+            vm_add_share "$node" "$share_path" "$SHARE_NAME"
+        fi
     done
 }