The get_image for GCE allows partial name matching and returns a
    libcloud object.

def __get_image(conn, vm_):
    '''
    The get_image for GCE allows partial name matching and returns a
    libcloud object.
    '''
    img = config.get_cloud_config_value(
        'image', vm_, __opts__, default='debian-7', search_global=False)
    return conn.ex_get_image(img)