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# Copyright 2011-present MongoDB, Inc.
# Licensed under the Apache License, Version 2.0 (the "License"); you
# may not use this file except in compliance with the License. You
# may obtain a copy of the License at
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# implied. See the License for the specific language governing
# permissions and limitations under the License.
"""Tools to parse and validate a MongoDB URI."""
import re
import warnings
from dns import resolver
except ImportError:
from bson.py3compat import PY3, string_type
if PY3:
from urllib.parse import unquote_plus
from urllib import unquote_plus
from pymongo.common import get_validated_options
from pymongo.errors import ConfigurationError, InvalidURI
SCHEME = 'mongodb://'
SRV_SCHEME = 'mongodb+srv://'
def _partition(entity, sep):
"""Python2.4 doesn't have a partition method so we provide
our own that mimics str.partition from later releases.
Split the string at the first occurrence of sep, and return a
3-tuple containing the part before the separator, the separator
itself, and the part after the separator. If the separator is not
found, return a 3-tuple containing the string itself, followed
by two empty strings.
parts = entity.split(sep, 1)
if len(parts) == 2:
return parts[0], sep, parts[1]
return entity, '', ''
def _rpartition(entity, sep):
"""Python2.4 doesn't have an rpartition method so we provide
our own that mimics str.rpartition from later releases.
Split the string at the last occurrence of sep, and return a
3-tuple containing the part before the separator, the separator
itself, and the part after the separator. If the separator is not
found, return a 3-tuple containing two empty strings, followed
by the string itself.
idx = entity.rfind(sep)
if idx == -1:
return '', '', entity
return entity[:idx], sep, entity[idx + 1:]
def parse_userinfo(userinfo):
"""Validates the format of user information in a MongoDB URI.
Reserved characters like ':', '/', '+' and '@' must be escaped
following RFC 3986.
Returns a 2-tuple containing the unescaped username followed
by the unescaped password.
- `userinfo`: A string of the form <username>:<password>
.. versionchanged:: 2.2
Now uses `urllib.unquote_plus` so `+` characters must be escaped.
if '@' in userinfo or userinfo.count(':') > 1:
if PY3:
quote_fn = "urllib.parse.quote_plus"
quote_fn = "urllib.quote_plus"
raise InvalidURI("Username and password must be escaped according to "
"RFC 3986, use %s()." % quote_fn)
user, _, passwd = _partition(userinfo, ":")
# No password is expected with GSSAPI authentication.
if not user:
raise InvalidURI("The empty string is not valid username.")
return unquote_plus(user), unquote_plus(passwd)
def parse_ipv6_literal_host(entity, default_port):
"""Validates an IPv6 literal host:port string.
Returns a 2-tuple of IPv6 literal followed by port where
port is default_port if it wasn't specified in entity.
- `entity`: A string that represents an IPv6 literal enclosed
in braces (e.g. '[::1]' or '[::1]:27017').
- `default_port`: The port number to use when one wasn't
specified in entity.
if entity.find(']') == -1:
raise ValueError("an IPv6 address literal must be "
"enclosed in '[' and ']' according "
"to RFC 2732.")
i = entity.find(']:')
if i == -1:
return entity[1:-1], default_port
return entity[1: i], entity[i + 2:]
def parse_host(entity, default_port=DEFAULT_PORT):
"""Validates a host string
Returns a 2-tuple of host followed by port where port is default_port
if it wasn't specified in the string.
- `entity`: A host or host:port string where host could be a
hostname or IP address.
- `default_port`: The port number to use when one wasn't
specified in entity.
host = entity
port = default_port
if entity[0] == '[':
host, port = parse_ipv6_literal_host(entity, default_port)
elif entity.endswith(".sock"):
return entity, default_port
elif entity.find(':') != -1:
if entity.count(':') > 1:
raise ValueError("Reserved characters such as ':' must be "
"escaped according RFC 2396. An IPv6 "
"address literal must be enclosed in '[' "
"and ']' according to RFC 2732.")
host, port = host.split(':', 1)
if isinstance(port, string_type):
if not port.isdigit() or int(port) > 65535 or int(port) <= 0:
raise ValueError("Port must be an integer between 0 and 65535: %s"
% (port,))
port = int(port)
# Normalize hostname to lowercase, since DNS is case-insensitive:
# This prevents useless rediscovery if "" is in the seed list but
# "" is in the ismaster response.
return host.lower(), port
def validate_options(opts, warn=False):
"""Validates and normalizes options passed in a MongoDB URI.
Returns a new dictionary of validated and normalized options. If warn is
False then errors will be thrown for invalid options, otherwise they will
be ignored and a warning will be issued.
- `opts`: A dict of MongoDB URI options.
- `warn` (optional): If ``True`` then warnigns will be logged and
invalid options will be ignored. Otherwise invalid options will
cause errors.
return get_validated_options(opts, warn)
def _parse_options(opts, delim):
"""Helper method for split_options which creates the options dict.
Also handles the creation of a list for the URI tag_sets/
readpreferencetags portion."""
options = {}
for opt in opts.split(delim):
key, val = opt.split("=")
if key.lower() == 'readpreferencetags':
options.setdefault('readpreferencetags', []).append(val)
# str(option) to ensure that a unicode URI results in plain 'str'
# option names. 'normalized' is then suitable to be passed as
# kwargs in all Python versions.
if str(key) in options:
warnings.warn("Duplicate URI option %s" % (str(key),))
options[str(key)] = unquote_plus(val)
# Special case for deprecated options
if "wtimeout" in options:
if "wtimeoutMS" in options:
warnings.warn("Option wtimeout is deprecated, use 'wtimeoutMS'"
" instead")
return options
def split_options(opts, validate=True, warn=False):
"""Takes the options portion of a MongoDB URI, validates each option
and returns the options in a dictionary.
- `opt`: A string representing MongoDB URI options.
- `validate`: If ``True`` (the default), validate and normalize all
and_idx = opts.find("&")
semi_idx = opts.find(";")
if and_idx >= 0 and semi_idx >= 0:
raise InvalidURI("Can not mix '&' and ';' for option separators.")
elif and_idx >= 0:
options = _parse_options(opts, "&")
elif semi_idx >= 0:
options = _parse_options(opts, ";")
elif opts.find("=") != -1:
options = _parse_options(opts, None)
raise ValueError
except ValueError:
raise InvalidURI("MongoDB URI options are key=value pairs.")
if validate:
return validate_options(options, warn)
return options
def split_hosts(hosts, default_port=DEFAULT_PORT):
"""Takes a string of the form host1[:port],host2[:port]... and
splits it into (host, port) tuples. If [:port] isn't present the
default_port is used.
Returns a set of 2-tuples containing the host name (or IP) followed by
port number.
- `hosts`: A string of the form host1[:port],host2[:port],...
- `default_port`: The port number to use when one wasn't specified
for a host.
nodes = []
for entity in hosts.split(','):
if not entity:
raise ConfigurationError("Empty host "
"(or extra comma in host list).")
port = default_port
# Unix socket entities don't have ports
if entity.endswith('.sock'):
port = None
nodes.append(parse_host(entity, port))
return nodes
# Prohibited characters in database name. DB names also can't have ".", but for
# backward-compat we allow "db.collection" in URI.
_BAD_DB_CHARS = re.compile('[' + re.escape(r'/ "$') + ']')
if PY3:
# dnspython can return bytes or str from various parts
# of its API depending on version. We always want str.
def maybe_decode(text):
if isinstance(text, bytes):
return text.decode()
return text
def maybe_decode(text):
return text
_ALLOWED_TXT_OPTS = frozenset(
['authsource', 'authSource', 'replicaset', 'replicaSet'])
def _get_dns_srv_hosts(hostname):
results = resolver.query('_mongodb._tcp.' + hostname, 'SRV')
except Exception as exc:
raise ConfigurationError(str(exc))
return [(maybe_decode(, res.port)
for res in results]
def _get_dns_txt_options(hostname):
results = resolver.query(hostname, 'TXT')
except (resolver.NoAnswer, resolver.NXDOMAIN):
# No TXT records
return None
except Exception as exc:
raise ConfigurationError(str(exc))
if len(results) > 1:
raise ConfigurationError('Only one TXT record is supported')
return (
b'&'.join([b''.join(res.strings) for res in results])).decode('utf-8')
def parse_uri(uri, default_port=DEFAULT_PORT, validate=True, warn=False):
"""Parse and validate a MongoDB URI.
Returns a dict of the form::
'nodelist': <list of (host, port) tuples>,
'username': <username> or None,
'password': <password> or None,
'database': <database name> or None,
'collection': <collection name> or None,
'options': <dict of MongoDB URI options>
If the URI scheme is "mongodb+srv://" DNS SRV and TXT lookups will be done
to build nodelist and options.
- `uri`: The MongoDB URI to parse.
- `default_port`: The port number to use when one wasn't specified
for a host in the URI.
- `validate`: If ``True`` (the default), validate and normalize all
- `warn` (optional): When validating, if ``True`` then will warn
the user then ignore any invalid options or values. If ``False``,
validation will error when options are unsupported or values are
.. versionchanged:: 3.6
Added support for mongodb+srv:// URIs
.. versionchanged:: 3.5
Return the original value of the ``readPreference`` MongoDB URI option
instead of the validated read preference mode.
.. versionchanged:: 3.1
``warn`` added so invalid options can be ignored.
if uri.startswith(SCHEME):
is_srv = False
scheme_free = uri[SCHEME_LEN:]
elif uri.startswith(SRV_SCHEME):
raise ConfigurationError('The "dnspython" module must be '
'installed to use mongodb+srv:// URIs')
is_srv = True
scheme_free = uri[SRV_SCHEME_LEN:]
raise InvalidURI("Invalid URI scheme: URI must "
"begin with '%s' or '%s'" % (SCHEME, SRV_SCHEME))
if not scheme_free:
raise InvalidURI("Must provide at least one hostname or IP.")
user = None
passwd = None
dbase = None
collection = None
options = {}
host_part, _, path_part = _partition(scheme_free, '/')
if not host_part:
host_part = path_part
path_part = ""
if not path_part and '?' in host_part:
raise InvalidURI("A '/' is required between "
"the host list and any options.")
if '@' in host_part:
userinfo, _, hosts = _rpartition(host_part, '@')
user, passwd = parse_userinfo(userinfo)
hosts = host_part
if '/' in hosts:
raise InvalidURI("Any '/' in a unix domain socket must be"
" percent-encoded: %s" % host_part)
hosts = unquote_plus(hosts)
if is_srv:
nodes = split_hosts(hosts, default_port=None)
if len(nodes) != 1:
raise InvalidURI(
"%s URIs must include one, "
"and only one, hostname" % (SRV_SCHEME,))
fqdn, port = nodes[0]
if port is not None:
raise InvalidURI(
"%s URIs must not include a port number" % (SRV_SCHEME,))
nodes = _get_dns_srv_hosts(fqdn)
plist = fqdn.split(".")[1:]
except Exception:
raise ConfigurationError("Invalid URI host")
slen = len(plist)
if slen < 2:
raise ConfigurationError("Invalid URI host")
for node in nodes:
nlist = node[0].split(".")[1:][-slen:]
except Exception:
raise ConfigurationError("Invalid SRV host")
if plist != nlist:
raise ConfigurationError("Invalid SRV host")
dns_options = _get_dns_txt_options(fqdn)
if dns_options:
options = split_options(dns_options, validate, warn)
if set(options) - _ALLOWED_TXT_OPTS:
raise ConfigurationError(
"Only authSource and replicaSet are supported from DNS")
options["ssl"] = True if validate else 'true'
nodes = split_hosts(hosts, default_port=default_port)
if path_part:
if path_part[0] == '?':
opts = unquote_plus(path_part[1:])
dbase, _, opts = map(unquote_plus, _partition(path_part, '?'))
if '.' in dbase:
dbase, collection = dbase.split('.', 1)
raise InvalidURI('Bad database name "%s"' % dbase)
if opts:
options.update(split_options(opts, validate, warn))
if dbase is not None:
dbase = unquote_plus(dbase)
if collection is not None:
collection = unquote_plus(collection)
return {
'nodelist': nodes,
'username': user,
'password': passwd,
'database': dbase,
'collection': collection,
'options': options
if __name__ == '__main__':
import pprint
import sys
except InvalidURI as exc: