ubuntu-cloudimage-keyring package should be dependency of maas-region-controller package

[Martin Nowack]

Installing maas-region-controller only on a server results in following error message in the web frontend:

Error: No boot sources provide Ubuntu images.
No Ubuntu images have been imported. Ubuntu images are required to allow nodes to enlist, commission, and install.

And following in:
django.log,

ERROR 2015-02-21 23:57:12,239 twisted Importing boot resources failed.
Traceback (most recent call last):
  File "/usr/lib/python2.7/threading.py", line 783, in __bootstrap
    self.__bootstrap_inner()
  File "/usr/lib/python2.7/threading.py", line 810, in __bootstrap_inner
    self.run()
  File "/usr/lib/python2.7/threading.py", line 763, in run
    self.__target(*self.__args, **self.__kwargs)
--- <exception caught here> ---
  File "/usr/lib/python2.7/dist-packages/twisted/python/threadpool.py", line 191, in _worker
    result = context.call(ctx, function, *args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/twisted/python/context.py", line 118, in callWithContext
    return self.currentContext().callWithContext(ctx, func, *args, **kw)
  File "/usr/lib/python2.7/dist-packages/twisted/python/context.py", line 81, in callWithContext
    return func(*args,**kw)
  File "/usr/lib/python2.7/dist-packages/provisioningserver/utils/twisted.py", line 148, in wrapper
    return func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/maasserver/bootresources.py", line 886, in _import_resources
    cache_boot_sources()
  File "/usr/lib/python2.7/dist-packages/maasserver/utils/async.py", line 153, in call_within_transaction
    return func(*args, **kwargs)
  File "/usr/lib/python2.7/dist-packages/maasserver/bootsources.py", line 133, in cache_boot_sources
    keyrings_path, [source.to_dict_without_selections()])
  File "/usr/lib/python2.7/dist-packages/maasserver/models/bootsource.py", line 78, in to_dict_without_selections
    with open(self.keyring_filename, 'rb') as keyring_file:
exceptions.IOError: [Errno 2] No such file or directory: u'/usr/share/keyrings/ubuntu-cloudimage-keyring.gpg'

This can be fixed with installing: ubuntu-cloudimage-keyring package

un maas <none> <none> (no description available)
un maas-cluster-controller <none> <none> (no description available)
ii maas-common 1.7.1+bzr3341-0ubuntu1~trusty1 all MAAS server common files
un maas-dhcp <none> <none> (no description available)
ii maas-dns 1.7.1+bzr3341-0ubuntu1~trusty1 all MAAS DNS server
ii maas-proxy 1.7.1+bzr3341-0ubuntu1~trusty1 all MAAS Caching Proxy
ii maas-region-controller 1.7.1+bzr3341-0ubuntu1~trusty1 all MAAS server complete region controller
ii maas-region-controller-min 1.7.1+bzr3341-0ubuntu1~trusty1 all MAAS Server minimum region controller
ii python-django-maas 1.7.1+bzr3341-0ubuntu1~trusty1 all MAAS server Django web framework
ii python-maas-client 1.7.1+bzr3341-0ubuntu1~trusty1 all MAAS python API client
ii python-maas-provisioningserver 1.7.1+bzr3341-0ubuntu1~trusty1 all MAAS server provisioning libraries