'A ``ConfigurationError`` is raised if in a fig application config, the
"links" key contains an application name that cannot be mapped to any
application present in the entire applications configuration.'

def test_invalid_fig_config_unknown_link(self):

    config = {u'postgres': {u'environment': {u'PG_ROOT_PASSWORD': u'clusterhq'}, u'image': u'sample/postgres', u'ports': [u'54320:5432'], u'volumes': [u'/var/lib/postgres'], u'links': [u'wordpress']}}
    parser = FigConfiguration(config)
    exception = self.assertRaises(ConfigurationError, parser.applications)
    error_message = u"Application    'postgres'    has    a    config    error.    'links'    value    'wordpress'    could    not    be    mapped    to    any    application;    application    'wordpress'    does    not    exist."
    self.assertEqual(exception.message, error_message)
