'Set the metadata for an image.
For a full list of available parameters, please refer to the official
API reference:
https://developer.openstack.org/api-ref/compute/#update-image-metadata'

def set_image_metadata(self, image_id, meta):

    post_body = json.dumps({'metadata': meta})
    (resp, body) = self.put(('images/%s/metadata' % image_id), post_body)
    body = json.loads(body)
    self.validate_response(schema.image_metadata, resp, body)
    return rest_client.ResponseBody(resp, body)
