Raise http.client.connect audit events in HTTPConnection (#2859)

changelog/2757.bugfix.rst

@@ -0,0 +1 @@
+Fixed ``urllib3.connection.HTTPConnection`` to raise the ``http.client.connect`` audit event to have the same behavior as the standard library HTTP client

src/urllib3/connection.py

@@ -5,6 +5,7 @@
 import os
 import re
 import socket
+import sys
 import typing
 import warnings
 from http.client import HTTPConnection as _HTTPConnection
@@ -76,6 +77,8 @@ class BaseSSLError(BaseException):  # type: ignore[no-redef]
 
 _CONTAINS_CONTROL_CHAR_RE = re.compile(r"[^-!#$%&'*+.^_`|~0-9a-zA-Z]")
 
+_HAS_SYS_AUDIT = hasattr(sys, "audit")
+
 
 class HTTPConnection(_HTTPConnection):
     """
@@ -216,6 +219,10 @@ def _new_conn(self) -> socket.socket:
                 self, f"Failed to establish a new connection: {e}"
             ) from e
 
+        # Audit hooks are only available in Python 3.8+
+        if _HAS_SYS_AUDIT:
+            sys.audit("http.client.connect", self, self.host, self.port)
+
         return sock
 
     def set_tunnel(

test/with_dummyserver/test_connection.py

@@ -1,7 +1,9 @@
 from __future__ import annotations
 
+import sys
 import typing
 from http.client import ResponseNotReady
+from unittest import mock
 
 import pytest
 
@@ -33,6 +35,19 @@ def test_returns_urllib3_HTTPResponse(pool: HTTPConnectionPool) -> None:
     assert isinstance(response, HTTPResponse)
 
 
+@pytest.mark.skipif(not hasattr(sys, "audit"), reason="requires python 3.8+")
+@mock.patch("urllib3.connection.sys.audit")
+def test_audit_event(audit_mock: mock.Mock, pool: HTTPConnectionPool) -> None:
+    conn = pool._get_conn()
+    conn.request("GET", "/")
+    audit_mock.assert_any_call("http.client.connect", conn, conn.host, conn.port)
+    # Ensure the event is raised only once.
+    connect_events = [
+        call for call in audit_mock.mock_calls if call.args[0] == "http.client.connect"
+    ]
+    assert len(connect_events) == 1
+
+
 def test_does_not_release_conn(pool: HTTPConnectionPool) -> None:
     conn = pool._get_conn()