1 files changed, 7 insertions, 5 deletions
diff --git a/buildscripts/resmokelib/testing/fixtures/interface.py b/buildscripts/resmokelib/testing/fixtures/interface.py
index 57d22f87ec6..1f9bf738fca 100644
--- a/buildscripts/resmokelib/testing/fixtures/interface.py
+++ b/buildscripts/resmokelib/testing/fixtures/interface.py
@@ -403,13 +403,15 @@ def create_fixture_table(fixture):
     return "Fixture status:\n" + table
 
 
-def authenticate(client, auth_options=None):
+def build_client(node, auth_options=None, read_preference=pymongo.ReadPreference.PRIMARY):
     """Authenticate client for the 'authenticationDatabase' and return the client."""
     if auth_options is not None:
-        auth_db = client[auth_options["authenticationDatabase"]]
-        auth_db.authenticate(auth_options["username"], password=auth_options["password"],
-                             mechanism=auth_options["authenticationMechanism"])
-    return client
+        return node.mongo_client(
+            username=auth_options["username"], password=auth_options["password"],
+            authSource=auth_options["authenticationDatabase"],
+            authMechanism=auth_options["authenticationMechanism"], read_preference=read_preference)
+    else:
+        return node.mongo_client(read_preference=read_preference)
 
 
 # Represents a row in a node info table.