Add missed stuff for offline

* Enable caching for DebMirror to save disk space
  Use caching logic to save disk space for DebMirror, so same packages
  in different repo versions will be used via hardlinks;
* Save in offline default Cirros/Fedora images.

Change-Id: I832d45167ad4b70b8349260614ffc8bbb9a911ca
Related-Prod: PROD-32735
diff --git a/defaults/linux_system_file.yml b/defaults/linux_system_file.yml
index c37c030..e0a9bfc 100644
--- a/defaults/linux_system_file.yml
+++ b/defaults/linux_system_file.yml
@@ -26,3 +26,9 @@
         amphora-x64-haproxy-queens.qcow2.md5:
           source: ${_param:mcp_binary_registry}/mirantis/openstack/octavia/images/${_param:mcp_version}/queens/amphora-x64-haproxy.qcow2.md5
           name: /srv/http/artifactory.mirantis.com/artifactory/binary-prod-local/mirantis/openstack/octavia/images/${_param:mcp_version}/queens/amphora-x64-haproxy.qcow2.md5
+        cirros-0.3.5-x86_64-disk.img:
+          source: ${_param:mcp_binary_registry}/mirantis/external/images/cirros/0.3.5/cirros-0.3.5-x86_64-disk.img
+          name: /srv/http/artifactory.mirantis.com/artifactory/binary-prod-local/mirantis/external/images/cirros/0.3.5/cirros-0.3.5-x86_64-disk.img
+        Fedora-Cloud-Base-27-1.6.x86_64.qcow2:
+          source: ${_param:mcp_binary_registry}/mirantis/external/images/cloud-fedora/27/Fedora-Cloud-Base-27-1.6.x86_64.qcow2
+          name: /srv/http/artifactory.mirantis.com/artifactory/binary-prod-local/mirantis/external/images/cloud-fedora/27/Fedora-Cloud-Base-27-1.6.x86_64.qcow2