1 files changed, 72 insertions, 0 deletions
diff --git a/tests/scripts/grandchild_wrapper.py b/tests/scripts/grandchild_wrapper.py
new file mode 100755
index 0000000..b5e7194
--- /dev/null
+++ b/tests/scripts/grandchild_wrapper.py
@@ -0,0 +1,72 @@
+#!/usr/bin/env python3
+# $OpenLDAP$
+## This work is part of OpenLDAP Software <http://www.openldap.org/>.
+##
+## Copyright 2020-2022 The OpenLDAP Foundation.
+## All rights reserved.
+##
+## Redistribution and use in source and binary forms, with or without
+## modification, are permitted only as authorized by the OpenLDAP
+## Public License.
+##
+## A copy of this license is available in the file LICENSE in the
+## top-level directory of the distribution or, alternatively, at
+## <http://www.OpenLDAP.org/license.html>.
+"""
+Running slapd under GDB in our testsuite, KILLPIDS would record gdb's PID
+rather than slapd's. When we want the server to shut down, SIGHUP is sent to
+KILLPIDS but GDB cannot handle being signalled directly and the entire thing is
+terminated immediately. There might be tests that rely on slapd being given the
+chance to shut down gracefully, to do this, we need to make sure the signal is
+actually sent to slapd.
+
+This script attempts to address this shortcoming in our test suite, serving as
+the front for gdb/other wrappers, catching SIGHUPs and redirecting them to the
+oldest living grandchild. The way we start up gdb, that process should be
+slapd, our intended target.
+
+This requires the pgrep utility provided by the procps package on Debian
+systems.
+"""
+
+import asyncio
+import os
+import signal
+import sys
+
+
+async def signal_to_grandchild(child):
+    # Get the first child, that should be the one we're after
+    pgrep = await asyncio.create_subprocess_exec(
+            "pgrep", "-o", "--parent", str(child.pid),
+            stdout=asyncio.subprocess.PIPE)
+
+    stdout, _ = await pgrep.communicate()
+    if not stdout:
+        return
+
+    grandchild = [int(pid) for pid in stdout.split()][0]
+
+    os.kill(grandchild, signal.SIGHUP)
+
+
+def sighup_handler(child):
+    asyncio.create_task(signal_to_grandchild(child))
+
+
+async def main(args=None):
+    if args is None:
+        args = sys.argv[1:]
+
+    child = await asyncio.create_subprocess_exec(*args)
+
+    # If we got a SIGHUP before we got the child fully started, there's no
+    # point signalling anyway
+    loop = asyncio.get_running_loop()
+    loop.add_signal_handler(signal.SIGHUP, sighup_handler, child)
+
+    raise SystemExit(await child.wait())
+
+
+if __name__ == '__main__':
+    asyncio.run(main())