support/testing/tests/package/test_python_paho_mqtt: new runtime test

This tests valdates that we can publish a message and read it back.

Signed-off-by: Marcus Hoffmann <marcus.hoffmann@othermo.de>
Tested-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
[yann.morin.1998@free.fr:
  - don't manually start mosquitto, there's a startup script for that
  - don't pass custom timeout
]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

support/testing/tests/package/sample_python_paho_mqtt.py

@@ -0,0 +1,12 @@
+from paho.mqtt import publish, subscribe
+
+publish.single(
+        'buildroot/test',
+        payload="Hello, World!",
+        qos=2,
+        retain=True,
+        hostname="localhost",
+        port=1883)
+
+message = subscribe.simple('buildroot/test')
+print(message.payload.decode())

support/testing/tests/package/test_python_paho_mqtt.py

@@ -0,0 +1,23 @@
+from tests.package.test_python import TestPythonPackageBase
+import os
+
+
+class TestPythonPahoMQTT(TestPythonPackageBase):
+    __test__ = True
+    config = TestPythonPackageBase.config + \
+        """
+        BR2_PACKAGE_MOSQUITTO=y
+        BR2_PACKAGE_MOSQUITTO_BROKER=y
+        BR2_PACKAGE_PYTHON3=y
+        BR2_PACKAGE_PYTHON_PAHO_MQTT=y
+        """
+    sample_scripts = ["tests/package/sample_python_paho_mqtt.py"]
+
+    def test_run(self):
+        self.login()
+        self.check_sample_scripts_exist()
+
+        cmd = "%s %s" % (self.interpreter, os.path.basename(self.sample_scripts[0]))
+        output, exit_code = self.emulator.run(cmd)
+        self.assertEqual(exit_code, 0)
+        self.assertEqual(output[0], "Hello, World!")