The FreeIPA integration tests strictly require Firewalld. But not all the distros have such or any other high-level tool for managing a firewall. Thus, to run integration tests on such systems NoOpFirewall class has been added, which provides no-op firewalld commands. Fixes: https://pagure.io/freeipa/issue/8261 Signed-off-by: Stanislav Levin <slev@altlinux.org> Reviewed-By: Rob Crittenden <rcritten@redhat.com> Reviewed-By: François Cami <fcami@redhat.com>