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quay/util/tufmetadata/api.py
2017-04-05 10:03:27 -04:00

127 lines
5.1 KiB
Python

import logging
from urlparse import urljoin
import requests
from data.database import CloseForLongOperation
from util.failover import failover, FailoverException
from util.security.instancekeys import InstanceKeys
from util.security.registry_jwt import build_context_and_subject, generate_bearer_token, QUAY_TUF_ROOT
DEFAULT_HTTP_HEADERS = {'Connection': 'close'}
MITM_CERT_PATH = '/conf/mitm.cert'
TOKEN_VALIDITY_LIFETIME_S = 60 * 60 # 1 hour
logger = logging.getLogger(__name__)
class InvalidMetadataException(Exception):
""" Exception raised when the upstream API metadata that doesn't parse correctly. """
pass
class Non200ResponseException(Exception):
""" Exception raised when the upstream API returns a non-200 HTTP status code. """
def __init__(self, response):
super(Non200ResponseException, self).__init__()
self.response = response
class TUFMetadataAPI(object):
""" Helper class for talking to the TUF Metadata service (Apostille). """
def __init__(self, app, config, client=None):
self._app = app
self._instance_keys = InstanceKeys(app)
self._config = config
self._client = client or config['HTTPCLIENT']
def get_default_tags(self, namespace, repository):
""" Gets the tag -> sha mappings in the 'targets/releases' delegation
"""
gun = "%s/%s" % (namespace, repository)
try:
response = self._get(gun, "targets/releases.json")
json_response = response.json()
targets = self._parse_targets(json_response)
except requests.exceptions.Timeout:
logger.exception('Timeout when trying to get metadata for %s', gun)
return None, True
except requests.exceptions.ConnectionError:
logger.exception('Connection error when trying to get metadata for %s', gun)
return None, True
except (requests.exceptions.RequestException, ValueError):
logger.exception('Failed to get metadata for %s', gun)
return None, False
except Non200ResponseException as ex:
return None, ex.response.status_code != 404 and ex.response.status_code != 400
except InvalidMetadataException as ex:
logger.exception('Failed to parse targets from metadata', str(ex))
return None, False
return targets, False
def _parse_targets(self, json_response):
""" Attempts to parse the targets from a metadata response """
signed = json_response.get('signed')
if not signed:
raise InvalidMetadataException("Could not find `signed` in metadata: %s" % json_response)
targets = signed.get('targets')
if not targets:
raise InvalidMetadataException("Could not find `targets` in metadata: %s" % json_response)
return targets
def _auth_header(self, gun):
""" Generate a registry auth token for apostille"""
access = [{
'type': 'repository',
'name': '%s/%s' % (self._config['SERVER_HOSTNAME'], gun),
'actions': ['pull'],
}]
context, subject = build_context_and_subject(user=None, token=None, oauthtoken=None, tuf_root=QUAY_TUF_ROOT)
token = generate_bearer_token("quay", subject, context, access,
TOKEN_VALIDITY_LIFETIME_S, self._instance_keys)
return {'Authorization': 'Bearer %s' % token}
def _get(self, gun, metadata_file):
return self._call('GET', '/v2/%s/_trust/tuf/%s' % (gun, metadata_file), headers=self._auth_header(gun))
def _request(self, method, endpoint, path, body, headers, params, timeout):
""" Issues an HTTP request to the signing endpoint. """
url = urljoin(endpoint, path)
logger.debug('%sing signing URL %s', method.upper(), url)
headers.update(DEFAULT_HTTP_HEADERS)
resp = self._client.request(method, url, json=body, params=params, timeout=timeout,
verify=MITM_CERT_PATH, headers=headers)
if resp.status_code // 100 != 2:
raise Non200ResponseException(resp)
return resp
def _call(self, method, path, params=None, body=None, headers=None):
""" Issues an HTTP request to signing service and handles failover for GET requests.
"""
if self._config is None:
raise Exception('Cannot call unconfigured signing service')
timeout = self._config.get('TUF_API_TIMEOUT_SECONDS', 1)
endpoint = self._config['TUF_SERVER']
with CloseForLongOperation(self._config):
# If the request isn't a read do not fail over.
if method != 'GET':
return self._request(method, endpoint, path, body, headers, params, timeout)
# The request is read-only and can failover.
all_endpoints = [endpoint] + self._config.get('TUF_READONLY_FAILOVER_ENDPOINTS', [])
return _failover_read_request(*[((self._request, endpoint, path, body, headers, params, timeout), {})
for endpoint in all_endpoints])
@failover
def _failover_read_request(request_fn, endpoint, path, body, headers, params, timeout):
""" This function auto-retries read-only requests until they return a 2xx status code. """
try:
return request_fn('GET', endpoint, path, body, headers, params, timeout)
except (requests.exceptions.RequestException, Non200ResponseException) as ex:
raise FailoverException(ex)