Issues using dbus in strict

[Sergey Borovkov]

So once the interfaces are connected the following happens:

1. In websocket service (the one that just calls methods over dbus) I can
get system bus without any issues.
2. In the second service, the one that exposes dbus interface I get
following exception when running this code:

    try:
        bus = SystemBus()
        bus.publish("com.screenly.playlist", playlist_service)
    except:
        log = logging.getLogger('screenly.PlaylistService')
        log.exception("Unable to register on system bus: ")

Apr 03 19:53:49 localhost.localdomain python3[1246]: screenly.PlaylistService
Unable to register on system bus:
                                                    Traceback (most recent
call last):
                                                      File
"/snap/screenly-client/x1/lib/python3.5/site-packages/pydbus/bus.py", line
43, in dbus
                                                        return self._dbus
                                                    AttributeError: 'Bus'
object has no attribute '_dbus'

                                                    During handling of the
above exception, another exception occurred:

                                                    Traceback (most recent
call last):
                                                      File
"/snap/screenly-client/x1/lib/python3.5/site-packages/screenly/client/playlist.py",
line 605, in main

bus.publish("com.screenly.playlist",
playlist_service)
                                                      File
"/snap/screenly-client/x1/lib/python3.5/site-packages/pydbus/publication.py",
line 42, in publish
                                                        return
Publication(self, bus_name, *objects)
                                                      File
"/snap/screenly-client/x1/lib/python3.5/site-packages/pydbus/publication.py",
line 35, in __init__

self._at_exit(bus.request_name(bus_name,
allow_replacement=allow_replacement, replace=replace).__exit__)
                                                      File
"/snap/screenly-client/x1/lib/python3.5/site-packages/pydbus/request_name.py",
line 29, in request_name
                                                        return
NameOwner(self, name, allow_replacement, replace)
                                                      File
"/snap/screenly-client/x1/lib/python3.5/site-packages/pydbus/request_name.py",
line 8, in __init__
                                                        res =
bus.dbus.RequestName(name, flags)
                                                      File
"/snap/screenly-client/x1/lib/python3.5/site-packages/pydbus/bus.py", line
45, in dbus
                                                        self._dbus =
self.get(".DBus")[""]
                                                      File
"/snap/screenly-client/x1/lib/python3.5/site-packages/pydbus/proxy.py",
line 47, in get
                                                        0,
timeout_to_glib(timeout), None)
                                                    GLib.GError:
g-dbus-error-quark: GDBus.Error:org.freedesktop.DBus.Error.AccessDenied: An
AppArmor policy prevents this sender from sending this message to this
recipient; type="