def connect_to_mongodb(db,
host,
port=27017,
tz_aware=True,
user=None,
password=None,
retry_wait_time=0.1,
proxy=True,
**kwargs):
"""
Returns a MongoDB Database connection, optionally wrapped in a proxy. The proxy
handles AutoReconnect errors by retrying read operations, since these exceptions
typically indicate a temporary step-down condition for MongoDB.
"""
# The MongoReplicaSetClient class is deprecated in Mongo 3.x, in favor of using
# the MongoClient class for all connections. Update/simplify this code when using
# PyMongo 3.x.
if kwargs.get('replicaSet'):
# Enable reading from secondary nodes in the MongoDB replicaset by using the
# MongoReplicaSetClient class.
# The 'replicaSet' parameter in kwargs is required for secondary reads.
# The read_preference should be set to a proper value, like SECONDARY_PREFERRED.
mongo_client_class = pymongo.MongoReplicaSetClient
else:
# No 'replicaSet' in kwargs - so no secondary reads.
mongo_client_class = pymongo.MongoClient
# If the MongoDB server uses a separate authentication database that should be specified here
auth_source = kwargs.get('authsource', '') or None
# sanitize a kwarg which may be present and is no longer expected
# AED 2020-03-02 TODO: Remove this when 'auth_source' will no longer exist in kwargs
if 'auth_source' in kwargs:
kwargs.pop('auth_source')
# If read_preference is given as a name of a valid ReadPreference.<NAME>
# constant such as "SECONDARY_PREFERRED" or a mongo mode such as
# "secondaryPreferred", convert it. Otherwise pass it through unchanged.
if 'read_preference' in kwargs:
read_preference = MONGO_READ_PREFERENCE_MAP.get(
kwargs['read_preference'], kwargs['read_preference'])
read_preference = getattr(ReadPreference, read_preference, None)
if read_preference is not None:
kwargs['read_preference'] = read_preference
mongo_conn = pymongo.database.Database(
mongo_client_class(host=host,
port=port,
tz_aware=tz_aware,
document_class=dict,
**kwargs), db)
if proxy:
mongo_conn = MongoProxy(mongo_conn, wait_time=retry_wait_time)
# If credentials were provided, authenticate the user.
if user is not None and password is not None:
mongo_conn.authenticate(user, password, source=auth_source)
return mongo_conn
def __init__(self,
db,
collection,
host,
port=27017,
tz_aware=True,
user=None,
password=None,
asset_collection=None,
retry_wait_time=0.1,
**kwargs):
"""
Create & open the connection, authenticate, and provide pointers to the collections
"""
self.database = MongoProxy(pymongo.database.Database(
pymongo.MongoClient(host=host,
port=port,
tz_aware=tz_aware,
**kwargs), db),
wait_time=retry_wait_time)
if user is not None and password is not None:
self.database.authenticate(user, password)
self.course_index = self.database[collection + '.active_versions']
self.structures = self.database[collection + '.structures']
self.definitions = self.database[collection + '.definitions']
# every app has write access to the db (v having a flag to indicate r/o v write)
# Force mongo to report errors, at the expense of performance
# pymongo docs suck but explanation:
# http://api.mongodb.org/java/2.10.1/com/mongodb/WriteConcern.html
self.course_index.write_concern = {'w': 1}
self.structures.write_concern = {'w': 1}
self.definitions.write_concern = {'w': 1}
def test_no_exceptions1(self):
mongo_connection = MongoProxy(
MongoConnection(),
methods_needing_retry={MongoConnection: [
'find',
]})
self.assertEqual(mongo_connection.find(), "Finished.")
self.assertEqual(mongo_connection.call_count, 1)
def test_exceptions2(self):
mongo_connection = MongoProxy(
MongoConnection(
exceptions_to_raise=[AutoReconnect, AutoReconnect]),
methods_needing_retry={MongoConnection: [
'find',
]})
self.assertEqual(mongo_connection.find(), "Finished.")
self.assertEqual(mongo_connection.call_count, 3)
def test_exceptions1(self):
mongo_connection = MongoProxy(
MongoConnection(exceptions_to_raise=[ValueError]),
methods_needing_retry={MongoConnection: [
'find',
]})
with self.assertRaises(ValueError):
mongo_connection.find()
self.assertEqual(mongo_connection.call_count, 1)
def connect_to_mongodb(db,
host,
port=27017,
tz_aware=True,
user=None,
password=None,
retry_wait_time=0.1,
proxy=True,
**kwargs):
"""
Returns a MongoDB Database connection, optionally wrapped in a proxy. The proxy
handles AutoReconnect errors by retrying read operations, since these exceptions
typically indicate a temporary step-down condition for MongoDB.
"""
# The MongoReplicaSetClient class is deprecated in Mongo 3.x, in favor of using
# the MongoClient class for all connections. Update/simplify this code when using
# PyMongo 3.x.
if kwargs.get('replicaSet'):
# Enable reading from secondary nodes in the MongoDB replicaset by using the
# MongoReplicaSetClient class.
# The 'replicaSet' parameter in kwargs is required for secondary reads.
# The read_preference should be set to a proper value, like SECONDARY_PREFERRED.
mongo_client_class = pymongo.MongoReplicaSetClient
else:
# No 'replicaSet' in kwargs - so no secondary reads.
mongo_client_class = pymongo.MongoClient
# If read_preference is given as a name of a valid ReadPreference.<NAME> constant
# such as "SECONDARY_PREFERRED", convert it. Otherwise pass it through unchanged.
if 'read_preference' in kwargs:
read_preference = getattr(ReadPreference, kwargs['read_preference'],
None)
if read_preference is not None:
kwargs['read_preference'] = read_preference
mongo_conn = pymongo.database.Database(
mongo_client_class(host=host,
port=port,
tz_aware=tz_aware,
document_class=dict,
**kwargs), db)
if proxy:
mongo_conn = MongoProxy(mongo_conn, wait_time=retry_wait_time)
# If credentials were provided, authenticate the user.
if user is not None and password is not None:
mongo_conn.authenticate(user, password)
return mongo_conn
def _connect_replica_set(self):
return MongoProxy(
pymongo.MongoReplicaSetClient(self.mongo_uri, self._replicaSet))
def _connect_server(self):
return MongoProxy(pymongo.MongoClient(self.mongo_uri))
