openqa_server: use guestfs direct backend for creating disks

this avoids the need to start and stop libvirtd.

roles/openqa/server/tasks/main.yml

@@ -82,38 +82,42 @@
   - /var/lib/openqa/share/factory/hdd
   - /var/lib/openqa/share/factory/repo
 
-- name: Start libvirt service
-  service: name=libvirtd state=started
-
 # NOTE: this is very hacky, but we can't do much better with the current
 # disk creation script, I will try and make it better. We'll have to bump
-# this hardcoded release number every so often.
+# this hardcoded release number every so often. Much better createhdds
+# is in review: https://phab.qadevel.cloud.fedoraproject.org/D687
+# LIBGUESTFS_BACKEND is to avoid the need to run libvirt just for this
 - name: Create hard disk images (this may take a long time!)
   command: "/root/openqa_fedora_tools/tools/createhdds.sh 23"
   args:
     creates: /var/lib/openqa/share/factory/hdd/disk_full_mbr.img
     chdir: /var/lib/openqa/share/factory/hdd/
+  environment:
+    LIBGUESTFS_BACKEND: direct
 
 - name: Create N-2 desktop x86_64 disk image (this may take a long time!)
   command: "/root/openqa_fedora_tools/tools/createhdds.sh 22 desktop_64bit"
   args:
     creates: /var/lib/openqa/share/factory/hdd/disk_f22_desktop_x86_64.img
     chdir: /var/lib/openqa/share/factory/hdd/
+  environment:
+    LIBGUESTFS_BACKEND: direct
 
 - name: Create N-2 desktop i686 disk image (this may take a long time!)
   command: "/root/openqa_fedora_tools/tools/createhdds.sh 22 desktop_32bit"
   args:
     creates: /var/lib/openqa/share/factory/hdd/disk_f22_desktop_i686.img
     chdir: /var/lib/openqa/share/factory/hdd/
+  environment:
+    LIBGUESTFS_BACKEND: direct
 
 - name: Create N-2 minimal x86_64 disk image (this may take a long time!)
   command: "/root/openqa_fedora_tools/tools/createhdds.sh 22 minimal_64bit"
   args:
     creates: /var/lib/openqa/share/factory/hdd/disk_f22_minimal_x86_64.img
     chdir: /var/lib/openqa/share/factory/hdd/
-
-- name: Stop libvirt service
-  service: name=libvirtd state=stopped
+  environment:
+    LIBGUESTFS_BACKEND: direct
 
 - name: Create exports file
   copy: src=exports dest=/etc/exports.d/openqa.exports owner=root group=root mode=0644