test: Wait for log entry to appear

As the servers can take a bit of time before emitting the log entry, wait a
bit before asserting the status.

kedifa/test.py

@@ -399,10 +399,21 @@ class KedifaIntegrationTest(KedifaCaucaseMixin, unittest.TestCase):
       'Entry %r not found in log:\n %s' % (entry, ''.join(log_line_list)))
 
   def assertLastLogEntry(self, entry):
-    with open(self.logfile) as fh:
-      last_log_line = fh.readlines()[-1]
-    self.assertTrue(
-      entry in last_log_line, '%r not found in %r' % (entry, last_log_line))
+    tries_left = 5  # try few times, as server can store the log line a bit
+                    # later
+    while True:
+      with open(self.logfile) as fh:
+        last_log_line = fh.readlines()[-1]
+      try:
+        self.assertTrue(
+          entry in last_log_line, '%r not found in %r' % (entry, last_log_line))
+      except AssertionError:
+        if tries_left == 0:
+          raise
+        tries_left -= 1
+        time.sleep(1)
+      else:
+        break
 
   def _getter_get(self, url, certificate, destination):
     cli.getter(