+import collections
+import httplib
import httplib2
import json
import logging
import os
import re
+import socket
+import time
import types
import apiclient
-import apiclient.discovery
-import apiclient.errors
+from apiclient import discovery as apiclient_discovery
+from apiclient import errors as apiclient_errors
import config
import errors
import util
_logger = logging.getLogger('arvados.api')
-conncache = {}
-class CredentialsFromToken(object):
- def __init__(self, api_token):
- self.api_token = api_token
+MAX_IDLE_CONNECTION_DURATION = 30
+RETRY_DELAY_INITIAL = 2
+RETRY_DELAY_BACKOFF = 2
+RETRY_COUNT = 2
- @staticmethod
- def http_request(self, uri, **kwargs):
- from httplib import BadStatusLine
- if 'headers' not in kwargs:
- kwargs['headers'] = {}
+class OrderedJsonModel(apiclient.model.JsonModel):
+ """Model class for JSON that preserves the contents' order.
- if config.get("ARVADOS_EXTERNAL_CLIENT", "") == "true":
- kwargs['headers']['X-External-Client'] = '1'
+ API clients that care about preserving the order of fields in API
+ server responses can use this model to do so, like this::
- kwargs['headers']['Authorization'] = 'OAuth2 %s' % self.arvados_api_token
+ from arvados.api import OrderedJsonModel
+ client = arvados.api('v1', ..., model=OrderedJsonModel())
+ """
+
+ def deserialize(self, content):
+ # This is a very slightly modified version of the parent class'
+ # implementation. Copyright (c) 2010 Google.
+ content = content.decode('utf-8')
+ body = json.loads(content, object_pairs_hook=collections.OrderedDict)
+ if self._data_wrapper and isinstance(body, dict) and 'data' in body:
+ body = body['data']
+ return body
+
+
+def _intercept_http_request(self, uri, **kwargs):
+ if (self.max_request_size and
+ kwargs.get('body') and
+ self.max_request_size < len(kwargs['body'])):
+ raise apiclient_errors.MediaUploadSizeError("Request size %i bytes exceeds published limit of %i bytes" % (len(kwargs['body']), self.max_request_size))
+
+ if 'headers' not in kwargs:
+ kwargs['headers'] = {}
+
+ if config.get("ARVADOS_EXTERNAL_CLIENT", "") == "true":
+ kwargs['headers']['X-External-Client'] = '1'
+
+ kwargs['headers']['Authorization'] = 'OAuth2 %s' % self.arvados_api_token
+
+ retryable = kwargs.get('method', 'GET') in [
+ 'DELETE', 'GET', 'HEAD', 'OPTIONS', 'PUT']
+ retry_count = self._retry_count if retryable else 0
+
+ if (not retryable and
+ time.time() - self._last_request_time > self._max_keepalive_idle):
+ # High probability of failure due to connection atrophy. Make
+ # sure this request [re]opens a new connection by closing and
+ # forgetting all cached connections first.
+ for conn in self.connections.itervalues():
+ conn.close()
+ self.connections.clear()
+
+ delay = self._retry_delay_initial
+ for _ in range(retry_count):
+ self._last_request_time = time.time()
try:
return self.orig_http_request(uri, **kwargs)
- except BadStatusLine:
- # This is how httplib tells us that it tried to reuse an
- # existing connection but it was already closed by the
- # server. In that case, yes, we would like to retry.
- # Unfortunately, we are not absolutely certain that the
- # previous call did not succeed, so this is slightly
- # risky.
- return self.orig_http_request(uri, **kwargs)
- def authorize(self, http):
- http.arvados_api_token = self.api_token
- http.orig_http_request = http.request
- http.request = types.MethodType(self.http_request, http)
- return http
+ except httplib.HTTPException:
+ _logger.debug("Retrying API request in %d s after HTTP error",
+ delay, exc_info=True)
+ except socket.error:
+ # This is the one case where httplib2 doesn't close the
+ # underlying connection first. Close all open
+ # connections, expecting this object only has the one
+ # connection to the API server. This is safe because
+ # httplib2 reopens connections when needed.
+ _logger.debug("Retrying API request in %d s after socket error",
+ delay, exc_info=True)
+ for conn in self.connections.itervalues():
+ conn.close()
+ time.sleep(delay)
+ delay = delay * self._retry_delay_backoff
+
+ self._last_request_time = time.time()
+ return self.orig_http_request(uri, **kwargs)
+
+def _patch_http_request(http, api_token):
+ http.arvados_api_token = api_token
+ http.max_request_size = 0
+ http.orig_http_request = http.request
+ http.request = types.MethodType(_intercept_http_request, http)
+ http._last_request_time = 0
+ http._max_keepalive_idle = MAX_IDLE_CONNECTION_DURATION
+ http._retry_delay_initial = RETRY_DELAY_INITIAL
+ http._retry_delay_backoff = RETRY_DELAY_BACKOFF
+ http._retry_count = RETRY_COUNT
+ return http
# Monkey patch discovery._cast() so objects and arrays get serialized
# with json.dumps() instead of str().
-_cast_orig = apiclient.discovery._cast
+_cast_orig = apiclient_discovery._cast
def _cast_objects_too(value, schema_type):
global _cast_orig
if (type(value) != type('') and
return json.dumps(value)
else:
return _cast_orig(value, schema_type)
-apiclient.discovery._cast = _cast_objects_too
+apiclient_discovery._cast = _cast_objects_too
# Convert apiclient's HttpErrors into our own API error subclass for better
# error reporting.
-# Reassigning apiclient.errors.HttpError is not sufficient because most of the
+# Reassigning apiclient_errors.HttpError is not sufficient because most of the
# apiclient submodules import the class into their own namespace.
def _new_http_error(cls, *args, **kwargs):
- return super(apiclient.errors.HttpError, cls).__new__(
+ return super(apiclient_errors.HttpError, cls).__new__(
errors.ApiError, *args, **kwargs)
-apiclient.errors.HttpError.__new__ = staticmethod(_new_http_error)
+apiclient_errors.HttpError.__new__ = staticmethod(_new_http_error)
def http_cache(data_type):
- path = os.environ['HOME'] + '/.cache/arvados/' + data_type
+ homedir = os.environ.get('HOME')
+ if not homedir or len(homedir) == 0:
+ return None
+ path = homedir + '/.cache/arvados/' + data_type
try:
util.mkdir_dash_p(path)
except OSError:
def api(version=None, cache=True, host=None, token=None, insecure=False, **kwargs):
"""Return an apiclient Resources object for an Arvados instance.
- Arguments:
- * version: A string naming the version of the Arvados API to use (for
+ :version:
+ A string naming the version of the Arvados API to use (for
example, 'v1').
- * cache: If True (default), return an existing Resources object if
- one already exists with the same endpoint and credentials. If
- False, create a new one, and do not keep it in the cache (i.e.,
- do not return it from subsequent api(cache=True) calls with
- matching endpoint and credentials).
- * host: The Arvados API server host (and optional :port) to connect to.
- * token: The authentication token to send with each API call.
- * insecure: If True, ignore SSL certificate validation errors.
+
+ :cache:
+ Use a cache (~/.cache/arvados/discovery) for the discovery
+ document.
+
+ :host:
+ The Arvados API server host (and optional :port) to connect to.
+
+ :token:
+ The authentication token to send with each API call.
+
+ :insecure:
+ If True, ignore SSL certificate validation errors.
Additional keyword arguments will be passed directly to
- `apiclient.discovery.build` if a new Resource object is created.
+ `apiclient_discovery.build` if a new Resource object is created.
If the `discoveryServiceUrl` or `http` keyword arguments are
missing, this function will set default values for them, based on
the current Arvados configuration settings.
elif host and token:
pass
elif not host and not token:
- # Load from user configuration or environment
- for x in ['ARVADOS_API_HOST', 'ARVADOS_API_TOKEN']:
- if x not in config.settings():
- raise ValueError("%s is not set. Aborting." % x)
- host = config.get('ARVADOS_API_HOST')
- token = config.get('ARVADOS_API_TOKEN')
- insecure = config.flag_is_true('ARVADOS_API_HOST_INSECURE')
+ return api_from_config(version=version, cache=cache, **kwargs)
else:
# Caller provided one but not the other
if not host:
kwargs['discoveryServiceUrl'] = (
'https://%s/discovery/v1/apis/{api}/{apiVersion}/rest' % (host,))
- if cache:
- connprofile = (version, host, token, insecure)
- svc = conncache.get(connprofile)
- if svc:
- return svc
-
if 'http' not in kwargs:
- http_kwargs = {}
- # Prefer system's CA certificates (if available) over httplib2's.
- certs_path = '/etc/ssl/certs/ca-certificates.crt'
- if os.path.exists(certs_path):
- http_kwargs['ca_certs'] = certs_path
+ http_kwargs = {'ca_certs': util.ca_certs_path()}
if cache:
http_kwargs['cache'] = http_cache('discovery')
if insecure:
http_kwargs['disable_ssl_certificate_validation'] = True
kwargs['http'] = httplib2.Http(**http_kwargs)
- credentials = CredentialsFromToken(api_token=token)
- kwargs['http'] = credentials.authorize(kwargs['http'])
+ kwargs['http'] = _patch_http_request(kwargs['http'], token)
- svc = apiclient.discovery.build('arvados', version, **kwargs)
+ svc = apiclient_discovery.build('arvados', version, **kwargs)
svc.api_token = token
+ svc.insecure = insecure
+ kwargs['http'].max_request_size = svc._rootDesc.get('maxRequestSize', 0)
kwargs['http'].cache = None
- if cache:
- conncache[connprofile] = svc
return svc
+
+def api_from_config(version=None, apiconfig=None, **kwargs):
+ """Return an apiclient Resources object enabling access to an Arvados server
+ instance.
+
+ :version:
+ A string naming the version of the Arvados REST API to use (for
+ example, 'v1').
+
+ :apiconfig:
+ If provided, this should be a dict-like object (must support the get()
+ method) with entries for ARVADOS_API_HOST, ARVADOS_API_TOKEN, and
+ optionally ARVADOS_API_HOST_INSECURE. If not provided, use
+ arvados.config (which gets these parameters from the environment by
+ default.)
+
+ Other keyword arguments such as `cache` will be passed along `api()`
+
+ """
+ # Load from user configuration or environment
+ if apiconfig is None:
+ apiconfig = config.settings()
+
+ for x in ['ARVADOS_API_HOST', 'ARVADOS_API_TOKEN']:
+ if x not in apiconfig:
+ raise ValueError("%s is not set. Aborting." % x)
+ host = apiconfig.get('ARVADOS_API_HOST')
+ token = apiconfig.get('ARVADOS_API_TOKEN')
+ insecure = config.flag_is_true('ARVADOS_API_HOST_INSECURE', apiconfig)
+
+ return api(version=version, host=host, token=token, insecure=insecure, **kwargs)