test(integration): add sysctl.

tests/bats/sysctl.bats

@@ -0,0 +1,27 @@
+#!/usr/bin/env bats
+# apparmor.d - Full set of apparmor profiles
+# Copyright (C) 2024 Alexandre Pujol <alexandre@pujol.io>
+# SPDX-License-Identifier: GPL-2.0-only
+
+load common
+
+@test "sysctl: Show all available variables and their values" {
+    sysctl -a
+}
+
+@test "sysctl: Set a changeable kernel state variable" {
+    sudo sysctl -w vm.panic_on_oom=0
+}
+
+@test "sysctl: Get currently open file handlers" {
+    sysctl fs.file-nr
+}
+
+@test "sysctl: Get limit for simultaneous open files" {
+    sysctl fs.file-max
+}
+
+@test "sysctl: Apply changes from `/etc/sysctl.conf`" {
+    sysctl -p
+}
+