feat(user_api_key_auth.py): allow restricting calls by IP address

Allows admin to restrict which IP addresses can make calls to the proxy

litellm/tests/test_user_api_key_auth.py

@@ -0,0 +1,46 @@
+# What is this?
+## Unit tests for user_api_key_auth helper functions
+
+import os
+import sys
+
+sys.path.insert(
+    0, os.path.abspath("../..")
+)  # Adds the parent directory to the system path
+from typing import List, Optional
+from unittest.mock import MagicMock
+
+import pytest
+
+import litellm
+
+
+class Request:
+    def __init__(self, client_ip: Optional[str] = None):
+        self.client = MagicMock()
+        self.client.host = client_ip
+
+
+@pytest.mark.parametrize(
+    "allowed_ips, client_ip, expected_result",
+    [
+        (None, "127.0.0.1", True),  # No IP restrictions, should be allowed
+        (["127.0.0.1"], "127.0.0.1", True),  # IP in allowed list
+        (["192.168.1.1"], "127.0.0.1", False),  # IP not in allowed list
+        ([], "127.0.0.1", False),  # Empty allowed list, no IP should be allowed
+        (["192.168.1.1", "10.0.0.1"], "10.0.0.1", True),  # IP in allowed list
+        (
+            ["192.168.1.1"],
+            None,
+            False,
+        ),  # Request with no client IP should not be allowed
+    ],
+)
+def test_check_valid_ip(
+    allowed_ips: Optional[List[str]], client_ip: Optional[str], expected_result: bool
+):
+    from litellm.proxy.auth.user_api_key_auth import _check_valid_ip
+
+    request = Request(client_ip)
+
+    assert _check_valid_ip(allowed_ips, request) == expected_result  # type: ignore