'Get container information and thusly verify container existence.
This will also verify account existence.
:param account: account name for the container
:param container: container name to look up
:param req: caller\'s HTTP request context object (optional)
:returns: dict containing at least container partition (\'partition\'),
container nodes (\'containers\'), container read
acl (\'read_acl\'), container write acl (\'write_acl\'),
and container sync key (\'sync_key\').
Values are set to None if the container does not exist.'

def container_info(self, account, container, req=None):

    (part, nodes) = self.app.container_ring.get_nodes(account, container)
    if req:
        env = getattr(req, 'environ', {})
    else:
        env = {}
    env.setdefault('swift.infocache', {})
    path_env = env.copy()
    path_env['PATH_INFO'] = ('/v1/%s/%s' % (account, container))
    info = get_container_info(path_env, self.app)
    if ((not info) or (not is_success(info.get('status')))):
        info = headers_to_container_info({}, 0)
        info['partition'] = None
        info['nodes'] = None
    else:
        info['partition'] = part
        info['nodes'] = nodes
    return info
