test_smoke_mab test flake

[gizmoguy]

Occasionally the MabTest.test_smoke_mab integration test fails for this reason:

 =================================== FAILURES ===================================
____________________________ MabTest.test_smoke_mab ____________________________

self = <test_mab.MabTest testMethod=test_smoke_mab>

    def test_smoke_mab(self):
        """Perform MAB using dhclient"""
        self.start_dhclient()
        time.sleep(5)
>       self.check_output()

chewie-src/test/integration/test_mab.py:21: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <test_mab.MabTest testMethod=test_smoke_mab>, kwargs = {}
file = <_io.TextIOWrapper name='/tmp/logs/chewie-MabTest-tgl5j990/chewie.log' mode='r' encoding='UTF-8'>
chewie_log = '2021-07-01 21:41:55,688 - CHEWIE - INFO - Starting chewie.\n2021-07-01 21:41:55,695 - CHEWIE.Chewie - INFO - Starting...EWIE.Chewie - INFO - waiting for MAB activity.\n2021-07-01 21:41:55,738 - CHEWIE.Chewie - INFO - waiting for radius.\n'
chewie_requirements = None

    def check_output(self, **kwargs):  # pylint: disable=no-self-use
        """Check the output of the Log Files to verify state of system"""
    
        with open(os.path.join(self.current_log_dir + "chewie.log"), "r") as file:
            chewie_log = file.read()
    
        chewie_requirements = kwargs.get("chewie_requirements", None)
        if chewie_requirements:
            for requirement in chewie_requirements:
                assert requirement in chewie_log, "Unable to find {} in chewie logs".format(
                    requirement, )
    
        currentframe = inspect.currentframe()
        assert currentframe
    
        if currentframe:
>           assert "Authentication successful" in chewie_log, "Authentication failed for {}".format(
                currentframe.f_back.f_code.co_name)
E           AssertionError: Authentication failed for test_smoke_mab
E           assert 'Authentication successful' in '2021-07-01 21:41:55,688 - CHEWIE - INFO - Starting chewie.\n2021-07-01 21:41:55,695 - CHEWIE.Chewie - INFO - Starting...EWIE.Chewie - INFO - waiting for MAB activity.\n2021-07-01 21:41:55,738 - CHEWIE.Chewie - INFO - waiting for radius.\n'

chewie-src/test/integration/base_test.py:229: AssertionError
----------------------------- Captured stdout call -----------------------------