tests.acceptance: adds multi vm capability for acceptance tests

This change adds the possibility to write acceptance tests with multi
virtual machine support. It's done keeping the virtual machines objects
stored in a test attribute (dictionary). This dictionary shouldn't be
accessed directly but through the new method added `get_vm`. This new
method accept a list of args (that will be added as virtual machine
arguments) and an optional name argument. The name is the key that
identify a single virtual machine along the test machines available. If
a name without a machine is informed a new machine will be instantiated.

The current usage of vm in tests will not be broken by this change since
it keeps a property called vm in the base test class. This property only
calls the new method `get_vm` with default parameters (no args and
'default' as machine name).

Signed-off-by: Caio Carrara <ccarrara@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Reviewed-by: Wainer dos Santos Moschetta <wainersm@redhat.com>
Message-Id: <20190212193855.13223-2-ccarrara@redhat.com>
Signed-off-by: Cleber Rosa <crosa@redhat.com>

1 files changed, 40 insertions, 1 deletions

diff --git a/docs/devel/testing.rst b/docs/devel/testing.rst
index 3ce171829d..60f897d915 100644
--- a/docs/devel/testing.rst
+++ b/docs/devel/testing.rst
@@ -633,7 +633,46 @@ instance, available at ``self.vm``.  Because many tests will tweak the
 QEMU command line, launching the QEMUMachine (by using ``self.vm.launch()``)
 is left to the test writer.
 
-At test "tear down", ``avocado_qemu.Test`` handles the QEMUMachine
+The base test class has also support for tests with more than one
+QEMUMachine. The way to get machines is through the ``self.get_vm()``
+method which will return a QEMUMachine instance. The ``self.get_vm()``
+method accepts arguments that will be passed to the QEMUMachine creation
+and also an optional `name` attribute so you can identify a specific
+machine and get it more than once through the tests methods. A simple
+and hypothetical example follows:
+
+.. code::
+
+  from avocado_qemu import Test
+
+
+  class MultipleMachines(Test):
+      """
+      :avocado: enable
+      """
+      def test_multiple_machines(self):
+          first_machine = self.get_vm()
+          second_machine = self.get_vm()
+          self.get_vm(name='third_machine').launch()
+
+          first_machine.launch()
+          second_machine.launch()
+
+          first_res = first_machine.command(
+              'human-monitor-command',
+              command_line='info version')
+
+          second_res = second_machine.command(
+              'human-monitor-command',
+              command_line='info version')
+
+          third_res = self.get_vm(name='third_machine').command(
+              'human-monitor-command',
+              command_line='info version')
+
+          self.assertEquals(first_res, second_res, third_res)
+
+At test "tear down", ``avocado_qemu.Test`` handles all the QEMUMachines
 shutdown.
 
 QEMUMachine