BigchainDB does not neet to initialize or check for replicaset

Signed-off-by: Shahbaz Nazir <shahbaz@bigchaindb.com>
This commit is contained in:
Shahbaz Nazir 2018-08-29 15:51:25 +02:00
parent 3f7b521809
commit 630895449e
2 changed files with 1 additions and 221 deletions

View File

@ -88,23 +88,6 @@ class LocalMongoDBConnection(Connection):
"""
try:
if self.replicaset:
# we should only return a connection if the replica set is
# initialized. initialize_replica_set will check if the
# replica set is initialized else it will initialize it.
initialize_replica_set(self.host,
self.port,
self.connection_timeout,
self.dbname,
self.ssl,
self.login,
self.password,
self.ca_cert,
self.certfile,
self.keyfile,
self.keyfile_passphrase,
self.crlfile)
# FYI: the connection process might raise a
# `ServerSelectionTimeoutError`, that is a subclass of
# `ConnectionFailure`.
@ -140,8 +123,6 @@ class LocalMongoDBConnection(Connection):
return client
# `initialize_replica_set` might raise `ConnectionFailure`,
# `OperationFailure` or `ConfigurationError`.
except (pymongo.errors.ConnectionFailure,
pymongo.errors.OperationFailure) as exc:
logger.info('Exception in _connect(): {}'.format(exc))
@ -152,121 +133,4 @@ class LocalMongoDBConnection(Connection):
MONGO_OPTS = {
'socketTimeoutMS': 20000,
}
def initialize_replica_set(host, port, connection_timeout, dbname, ssl, login,
password, ca_cert, certfile, keyfile,
keyfile_passphrase, crlfile):
"""Initialize a replica set. If already initialized skip."""
# Setup a MongoDB connection
# The reason we do this instead of `backend.connect` is that
# `backend.connect` will connect you to a replica set but this fails if
# you try to connect to a replica set that is not yet initialized
try:
# The presence of ca_cert, certfile, keyfile, crlfile implies the
# use of certificates for TLS connectivity.
if ca_cert is None or certfile is None or keyfile is None or \
crlfile is None:
conn = pymongo.MongoClient(host,
port,
serverselectiontimeoutms=connection_timeout,
ssl=ssl,
**MONGO_OPTS)
if login is not None and password is not None:
conn[dbname].authenticate(login, password)
else:
logger.info('Connecting to MongoDB over TLS/SSL...')
conn = pymongo.MongoClient(host,
port,
serverselectiontimeoutms=connection_timeout,
ssl=ssl,
ssl_ca_certs=ca_cert,
ssl_certfile=certfile,
ssl_keyfile=keyfile,
ssl_pem_passphrase=keyfile_passphrase,
ssl_crlfile=crlfile,
ssl_cert_reqs=CERT_REQUIRED,
**MONGO_OPTS)
if login is not None:
logger.info('Authenticating to the database...')
conn[dbname].authenticate(login, mechanism='MONGODB-X509')
except (pymongo.errors.ConnectionFailure,
pymongo.errors.OperationFailure) as exc:
logger.info('Exception in _connect(): {}'.format(exc))
raise ConnectionError(str(exc)) from exc
except pymongo.errors.ConfigurationError as exc:
raise ConfigurationError from exc
_check_replica_set(conn)
host = '{}:{}'.format(bigchaindb.config['database']['host'],
bigchaindb.config['database']['port'])
config = {'_id': bigchaindb.config['database']['replicaset'],
'members': [{'_id': 0, 'host': host}]}
try:
conn.admin.command('replSetInitiate', config)
except pymongo.errors.OperationFailure as exc_info:
if exc_info.details['codeName'] == 'AlreadyInitialized':
return
raise
else:
_wait_for_replica_set_initialization(conn)
logger.info('Initialized replica set')
finally:
if conn is not None:
logger.info('Closing initial connection to MongoDB')
conn.close()
def _check_replica_set(conn):
"""Checks if the replSet option was enabled either through the command
line option or config file and if it matches the one provided by
bigchaindb configuration.
Note:
The setting we are looking for will have a different name depending
if it was set by the config file (`replSetName`) or by command
line arguments (`replSet`).
Raise:
:exc:`~ConfigurationError`: If mongod was not started with the
replSet option.
"""
options = conn.admin.command('getCmdLineOpts')
try:
repl_opts = options['parsed']['replication']
repl_set_name = repl_opts.get('replSetName', repl_opts.get('replSet'))
except KeyError:
raise ConfigurationError('mongod was not started with'
' the replSet option.')
bdb_repl_set_name = bigchaindb.config['database']['replicaset']
if repl_set_name != bdb_repl_set_name:
raise ConfigurationError('The replicaset configuration of '
'bigchaindb (`{}`) needs to match '
'the replica set name from MongoDB'
' (`{}`)'.format(bdb_repl_set_name,
repl_set_name))
def _wait_for_replica_set_initialization(conn):
"""Wait for a replica set to finish initialization.
If a replica set is being initialized for the first time it takes some
time. Nodes need to discover each other and an election needs to take
place. During this time the database is not writable so we need to wait
before continuing with the rest of the initialization
"""
# I did not find a better way to do this for now.
# To check if the database is ready we will poll the mongodb logs until
# we find the line that says the database is ready
logger.info('Waiting for mongodb replica set initialization')
while True:
logs = conn.admin.command('getLog', 'rs')['log']
if any('database writes are now permitted' in line for line in logs):
return
time.sleep(0.1)
}

View File

@ -109,87 +109,3 @@ def test_connection_with_credentials(mock_authenticate):
password='secret')
conn.connect()
assert mock_authenticate.call_count == 1
def test_check_replica_set_not_enabled(mongodb_connection):
from bigchaindb.backend.localmongodb.connection import _check_replica_set
from bigchaindb.common.exceptions import ConfigurationError
# no replSet option set
cmd_line_opts = {'argv': ['mongod', '--dbpath=/data'],
'ok': 1.0,
'parsed': {'storage': {'dbPath': '/data'}}}
with mock.patch.object(Database, 'command', return_value=cmd_line_opts):
with pytest.raises(ConfigurationError):
_check_replica_set(mongodb_connection)
def test_check_replica_set_command_line(mongodb_connection,
mock_cmd_line_opts):
from bigchaindb.backend.localmongodb.connection import _check_replica_set
# replSet option set through the command line
with mock.patch.object(Database, 'command',
return_value=mock_cmd_line_opts):
assert _check_replica_set(mongodb_connection) is None
def test_check_replica_set_config_file(mongodb_connection, mock_config_opts):
from bigchaindb.backend.localmongodb.connection import _check_replica_set
# replSet option set through the config file
with mock.patch.object(Database, 'command', return_value=mock_config_opts):
assert _check_replica_set(mongodb_connection) is None
def test_check_replica_set_name_mismatch(mongodb_connection,
mock_cmd_line_opts):
from bigchaindb.backend.localmongodb.connection import _check_replica_set
from bigchaindb.common.exceptions import ConfigurationError
# change the replica set name so it does not match the bigchaindb config
mock_cmd_line_opts['parsed']['replication']['replSet'] = 'rs0'
with mock.patch.object(Database, 'command',
return_value=mock_cmd_line_opts):
with pytest.raises(ConfigurationError):
_check_replica_set(mongodb_connection)
def test_wait_for_replica_set_initialization(mongodb_connection):
from bigchaindb.backend.localmongodb.connection import _wait_for_replica_set_initialization # noqa
with mock.patch.object(Database, 'command') as mock_command:
mock_command.side_effect = [
{'log': ['a line']},
{'log': ['database writes are now permitted']},
]
# check that it returns
assert _wait_for_replica_set_initialization(mongodb_connection) is None
def test_initialize_replica_set(mock_cmd_line_opts):
from bigchaindb.backend.localmongodb.connection import initialize_replica_set
with mock.patch.object(Database, 'command') as mock_command:
mock_command.side_effect = [
mock_cmd_line_opts,
None,
{'log': ['database writes are now permitted']},
]
# check that it returns
assert initialize_replica_set('host', 1337, 1000, 'dbname', False, None, None,
None, None, None, None, None) is None
# test it raises OperationError if anything wrong
with mock.patch.object(Database, 'command') as mock_command:
mock_command.side_effect = [
mock_cmd_line_opts,
pymongo.errors.OperationFailure(None, details={'codeName': ''})
]
with pytest.raises(pymongo.errors.OperationFailure):
initialize_replica_set('host', 1337, 1000, 'dbname', False, None,
None, None, None, None, None, None) is None