always use for source

Author: blink1073

.evergreen/run-mongodb-oidc-test.sh

@@ -23,7 +23,7 @@ shopt -s expand_aliases # needed for `urlencode` alias
 
 MONGODB_URI=${MONGODB_URI:-"mongodb://localhost"}
 MONGODB_URI_SINGLE="${MONGODB_URI}/?authMechanism=MONGODB-OIDC"
-MONGODB_URI_MULTIPLE="${MONGODB_URI}:27018/?authMechanism=MONGODB-OIDC&directConnection=true"
+MONGODB_URI_MULTIPLE="mongodb+srv://cluster0.oztdp.mongodb-dev.net/?authMechanism=MONGODB-OIDC"
 
 if [ -z "${OIDC_TOKEN_DIR}" ]; then
     echo "Must specify OIDC_TOKEN_DIR"

pymongo/auth.py

@@ -140,8 +140,6 @@ def _build_credentials_tuple(mech, source, user, passwd, extra, database):
         # user can be None for temporary link-local EC2 credentials.
         return MongoCredential(mech, "$external", user, passwd, aws_props, None)
     elif mech == "MONGODB-OIDC":
-        if source is not None and source != "$external":
-            raise ValueError("authentication source must be $external or None for MONGODB-OIDC")
         properties = extra.get("authmechanismproperties", {})
         request_token_callback = properties.get("request_token_callback")
         refresh_token_callback = properties.get("refresh_token_callback", None)