Zero out the inventory cache instead of removing it

https://github.com/ansible/ansible/pull/14882 landed, so the inventory
will understand that an empty cache means the inventory needs
refetching. Zero out the file, and start consuming inventory from the
master branch of ansible since mordred controls that file anyway.

Change-Id: I2a4f4b21c50bfa94a229dd109e3d21f47552f0a1

launch/launch-node.py

@@ -256,10 +256,12 @@ def main():
                           options.network, options.boot_from_volume,
                           options.config_drive)
     dns.print_dns(cloud, server)
-    # Remove the ansible inventory cache so that next run finds the new
-    # server
-    if os.path.exists('/var/cache/ansible-inventory/ansible-inventory.cache'):
-        os.unlink('/var/cache/ansible-inventory/ansible-inventory.cache')
+
+    # Zero the ansible inventory cache so that next run finds the new server
+    inventory_cache = '/var/cache/ansible-inventory/ansible-inventory.cache'
+    if os.path.exists(inventory_cache):
+        with open(inventory_cache, 'w'):
+            pass
     os.system('/usr/local/bin/expand-groups.sh')
 
 if __name__ == '__main__':

modules/openstack_project/manifests/puppetmaster.pp

@@ -227,7 +227,7 @@ class openstack_project::puppetmaster (
   vcsrepo { '/opt/ansible':
     ensure   => latest,
     provider => git,
-    revision => 'stable-2.0',
+    revision => 'devel',
     source   => 'https://github.com/ansible/ansible',
   }