support/testing: remove hardcoded sleep from python-django test

Instead of waiting for a hardcoded time of 30s we check periodically every
second if the server is already up. If it isn't up after the full timeout
(which is the same as before) expired the test fails.

We need to redirect all output of the background started task to
/dev/null now as it otherwise confuses the emulator.run() exit code
parsing logic (as it gets out of order messages from the emulator).

Signed-off-by: Marcus Hoffmann <buildroot@bubu1.eu>
yann.morin.1998@free.fr: simplify assert test]
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

support/testing/tests/package/test_python_django.py

@@ -1,3 +1,5 @@
+import time
+
 from tests.package.test_python import TestPythonPackageBase
 
 
@@ -16,13 +18,16 @@ class TestPythonDjango(TestPythonPackageBase):
         self.assertIn("Operations to perform:", output[0])
         self.assertEqual(exit_code, 0)
 
-        cmd = "cd /opt/testsite && " + self.interpreter + " ./manage.py runserver 0.0.0.0:1234 & "
-        # give some time to setup the server
-        cmd += "sleep {}".format(str(30 * self.emulator.timeout_multiplier))
+        cmd = "cd /opt/testsite && " + self.interpreter + " ./manage.py runserver 0.0.0.0:1234 > /dev/null 2>&1 & "
         self.assertRunOk(cmd, timeout=timeout)
-
-        cmd = "netstat -ltn 2>/dev/null | grep 0.0.0.0:1234"
-        self.assertRunOk(cmd)
+        # give some time to setup the server
+        for attempt in range(30 * self.emulator.timeout_multiplier):
+            time.sleep(1)
+            cmd = "netstat -ltn 2>/dev/null | grep 0.0.0.0:1234"
+            _, exit_code = self.emulator.run(cmd)
+            if exit_code == 0:
+                break
+        self.assertEqual(exit_code, 0, "Timeout while waiting for django server")
 
 
 class TestPythonPy3Django(TestPythonDjango):