blob: 4fb491812a06d29eecb3ad0a1f620d34f5b29b18 [file] [log] [blame]
# -*- coding: utf-8 -*-
# Copyright 2018 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
# This file is heavily based off of LUCI It's been adopted to remove
# AppEngine-ism and convert from urllib to httplib2.
"""Wrapper around httplib2 to call REST API with service account credentials."""
from __future__ import print_function
import httplib2
import six
from six.moves import urllib
from chromite.lib import auth
from chromite.lib import constants
from chromite.lib import cros_logging as logging
def httprequest(http, **kwargs):
"""To be mocked in tests."""
return http.request(**kwargs)
class Error(Exception):
"""Raised on non-transient errors.
Attribute response is response body.
def __init__(self, msg, status_code, response, headers=None):
super(Error, self).__init__(msg)
self.status_code = status_code
self.headers = headers
self.response = response
class NotFoundError(Error):
"""Raised if endpoint returns 404."""
class AuthError(Error):
"""Raised if endpoint returns 401 or 403."""
def is_transient_error(response, url):
"""Returns True to retry the request."""
if response.status >= 500 or response.status == 408:
return True
# Retry 404 iff it is a Cloud Endpoints API call *and* the
# result is not JSON. This assumes that we only use JSON encoding.
if response.status == 404:
content_type = response.get('content-type', '')
return (urllib.parse.urlparse(url).path.startswith('/_ah/api/') and
not content_type.startswith('application/json'))
return False
def _error_class_for_status(status_code):
if status_code == 404:
return NotFoundError
if status_code in (401, 403):
return AuthError
return Error
def request(url,
"""Sends a REST API request, returns raw unparsed response.
Retries the request on transient errors for up to |max_attempts| times.
url: url to send the request to.
method: HTTP method to use, e.g. GET, POST, PUT.
payload: raw data to put in the request body.
params: dict with query GET parameters (i.e. ?key=value&key=value).
headers: additional request headers.
include_auth: Whether to include an OAuth2 access token.
delegation_token: delegation token returned by auth.delegate.
deadline: deadline for a single attempt (10 sec by default).
max_attempts: how many times to retry on errors (4 times by default).
Buffer with raw response.
NotFoundError on 404 response.
AuthError on 401 or 403 response.
Error on any other non-transient error.
protocols = ('http://', 'https://')
assert url.startswith(protocols) and '?' not in url, url
if params:
url += '?' + urllib.parse.urlencode(params)
headers = (headers or {}).copy()
if include_auth:
tok = auth.GetAccessToken(
headers['Authorization'] = 'Bearer %s' % tok
if payload is not None:
assert isinstance(payload, (six.string_types, six.binary_type)), \
assert method in ('CREATE', 'POST', 'PUT'), method
attempt = 0
response = None
last_status_code = None
http = httplib2.Http(cache=None, timeout=deadline)
http.follow_redirects = False
while attempt < max_attempts:
if attempt:'Retrying: %s %s', method, url)
attempt += 1
response, content = httprequest(
http, uri=url, method=method, headers=headers, body=payload)
except httplib2.HttpLib2Error as e:
# Transient network error or URL fetch service RPC deadline.
logging.warning('%s %s failed: %s', method, url, e)
last_status_code = response.status
# Transient error on the other side.
if is_transient_error(response, url):
logging.warning('%s %s failed with HTTP %d\nHeaders: %r\nBody: %r',
method, url, response.status, response, content)
# Non-transient error.
if 300 <= response.status < 500:
logging.warning('%s %s failed with HTTP %d\nHeaders: %r\nBody: %r',
method, url, response.status, response, content)
raise _error_class_for_status(response.status)(
'Failed to call %s: HTTP %d' % (url, response.status),
# Success. Beware of large responses.
if len(content) > 1024 * 1024:
logging.warning('Response size: %.1f KiB', len(content) / 1024.0)
return content
raise _error_class_for_status(last_status_code)(
'Failed to call %s after %d attempts' % (url, max_attempts),
response.status if response else None,
content if response else None,
headers=response if response else None)