test: skip TEST-43-PRIVATEUSER-UNPRIV if unprivileged userns is restr…

…icted

With newer versions of AppArmor, unprivileged user namespace creation
may be restricted by default, in which case user manager instances will
not be able to apply PrivateUsers=yes (or the settings which require it).

This can be tested with the kernel.apparmor_restrict_unprivileged_userns
sysctl.

test/units/testsuite-43.sh

@@ -6,6 +6,11 @@ set -o pipefail
 # shellcheck source=test/units/util.sh
 . "$(dirname "$0")"/util.sh
 
+if [[ "$(sysctl -ne kernel.apparmor_restrict_unprivileged_userns)" -eq 1 ]]; then
+    echo "Cannot create unprivileged user namespaces" >/skipped
+    exit 0
+fi
+
 systemd-analyze log-level debug
 
 runas testuser systemd-run --wait --user --unit=test-private-users \