Swift temp url

gistfile1.py

def _get_swift_temp_urls(self, url):
    try:
        key = SWIFT_TEMP_URL_KEY.encode('ascii', 'ignore')
    except UnicodeDecodeError:
        raise ValueError('SWIFT_TEMP_URL_KEY must be an ascii key.')
    try:
        temp_url_duration = int(SWIFT_TEMP_URL_DURATION)
    except ValueError:
        raise ValueError('SWIFT_TEMP_URL_DURATION must be an integer.')
    method = SWIFT_TEMP_URL_METHOD
    if method not in ['GET', 'PUT']:
        raise ValueError('SWIFT_TEMP_URL_METHOD must be either GET or PUT')
    
    # Parse out filename from glance url
    try:
        object_name = url['file'].split('/')[3]
    except KeyError as e:
        raise self.ImageProviderException(
            'Image URL {} improperly formatted'.format(str(e))
        )
    
    template = '/v1/AUTH_{tenant}/{container}/{object_name}'
    url = template.format(tenant=KEYSTONE_TENANT_ID,
                          container=GLANCE_SWIFT_CONTAINER,
                          object_name=object_name).lstrip('/')
    
    expiration = int(time.time() + temp_url_duration)
    hmac_body = '\n'.join([method, str(expiration), url])
    sig = hmac.new(key, hmac_body, hashlib.sha1).hexdigest()
    host = SWIFT_URL.rstrip('/')
    return '{host}/{url}?temp_url_sig={sig}&temp_url_expires={exp}'
            .format(host=host, url=url, sig=sig, exp=expiration)