Canonical Voices

Posts tagged with 'd-bus'

pitti

I just pushed out a new python-dbusmock release 0.6.

Calling a method on the mock now emits a MethodCalled signal on the org.freedesktop.DBus.Mock interface. In some cases this is easier to track than parsing the mock’s log or using GetMethodCalls. Thanks to Lars Uebernickel for this.

DBusMockObject.AddTemplate() and DBusTestCase.spawn_server_template() can now load local templates from your own project by specifying a path to a *.py file as template name. Thanks to Lucas De Marchi for this feature.

I also wrote a quite comprehensive template for systemd’s logind. It stubs out the power management functionality as well as user/seat/session objects, and is convincing enough for loginctl. Some bits like AttachDevice is missing, as this sounds unlikely to be required for D-BUS mock tests, but please let me know if you need anything else.

The mock processes now terminate automatically if their connected D-BUS goes down, as advertised in the documentation.

You can get the new tarball from Launchpad, and I uploaded it to Debian experimental now.

Enjoy!

Read more
pitti

With python-dbusmock you can provide mocks for arbitrary D-BUS services for your test suites or if you want to reproduce a bug.

However, when writing actual tests for gnome-settings-daemon etc. I noticed that it is rather cumbersome to always have to set up the “skeleton” of common services such as UPower. python-dbusmock 0.2 now introduces the concept of “templates” which provide those skeletons for common standard services so that your code only needs to set up the particular properties and specific D-BUS objects that you need. These templates can be parameterized for common customizations, and they can provide additional convenience methods on the org.freedesktop.DBus.Mock interface to provide more abstract functionality like “add a battery”.

So if you want to pretend you have one AC and a half-charged battery, you can now simply do

  def setUp(self):
     (self.p_mock, self.obj_upower) = self.spawn_server_template('upower', {})

  def test_ac_bat(self):
     self.obj_upower.AddAC('mock_AC', 'Mock AC')
     self.obj_upower.AddChargingBattery('mock_BAT', 'Mock Battery', 50.0, 1200)

Or, if your code is not in Python, use the CLI/D-BUS interface, like in shell:

  # start a fake system bus
  eval `dbus-launch`
  export DBUS_SYSTEM_BUS_ADDRESS=$DBUS_SESSION_BUS_ADDRESS

  # start mock upower on the fake bus
  python3 -m dbusmock --template upower &

  # add devices
  gdbus call --system -d org.freedesktop.UPower -o /org/freedesktop/UPower \
      -m org.freedesktop.DBus.Mock.AddAC mock_ac 'Mock AC'
  gdbus call --system -d org.freedesktop.UPower -o /org/freedesktop/UPower \
      -m org.freedesktop.DBus.Mock.AddChargingBattery mock_bat 'Mock Bat' 50.0 1200

In both cases upower --dump or gnome-power-statistics will show you the expected devices (of course you need to run that within the environment of the fake $DBUS_SYSTEM_BUS_ADDRESS, or run the mock on the real system bus as root).

Iftikhar Ahmad contributed a template for NetworkManager, which allows you to easily set up ethernet and wifi devices and wifi access points. See pydoc3 dbusmock.templates.networkmanager for details and the test cases for how this looks like in practice.

I just released python-dbusmock 0.2.1 and uploaded the new version to Debian experimental. I will sync it into Ubuntu Raring in a few hours.

Read more
pitti

On the long flight back from UDS-Lucid I read the Vala tutorial on my ebook, and did some of the exercises. I was curious about Vala because it combines the speed and memory efficiency of C in a sane C#-like language with proper memory management, exceptions, and without the silly “close to the metal” faff that is usually required in C.

And indeed I wasn’t disappointed. It’s not as convenient as Python, but really not far from it, and it’s faaaast!

Today I finally got back to this and wrote my first D-Bus example in vala which does a call to DeviceKit-disks:

using DBus;

int main(string[] args)
{
    Connection con = Bus.get(BusType.SYSTEM);

    dynamic DBus.Object dk = con.get_object(
            "org.freedesktop.DeviceKit.Disks",
	    "/org/freedesktop/DeviceKit/Disks",
	    "org.freedesktop.DeviceKit.Disks");

    ObjectPath[] devs = dk.EnumerateDevices();
    foreach (ObjectPath o in devs)
	stdout.printf("%s\n", o);

    return 0;
}

Compile and run it with

valac --pkg dbus-glib-1 dbus-dk.vala && ./dbus-dk

and voila!

Read more