[202012 platform_tests] TestWatchdogApi::test_remaining_time failure on vms20-t1-7050cx3-3.1

[sujinmkang]

Description

Lastest 202012 image has sonic-mgmt/tests/platform_tests/api/test_watchdog.py::TestWatchdogApi::test_remaining_time failure on vms20-t1-7050cx3-3.1

Steps to reproduce the issue:

Describe the results you received:

2021-08-10T12:04:31.9713678Z def test_remaining_time(self, duthosts, enum_rand_one_per_hwsku_hostname, platform_api_conn, conf):
2021-08-10T12:04:31.9716763Z ''' arm watchdog with a valid timeout and verify that remaining time API works correctly '''
2021-08-10T12:04:31.9719334Z
2021-08-10T12:04:31.9721866Z watchdog_timeout = conf['valid_timeout']
2021-08-10T12:04:31.9725462Z
2021-08-10T12:04:31.9728442Z # in the begginging of the test watchdog is not armed, so
2021-08-10T12:04:31.9731230Z # get_remaining_time has to return -1
2021-08-10T12:04:31.9733571Z remaining_time = watchdog.get_remaining_time(platform_api_conn)
2021-08-10T12:04:31.9736379Z if self.expect(remaining_time is not None and remaining_time is -1, "watchdog should be disabled in the initial state"):
2021-08-10T12:04:31.9739327Z actual_timeout = watchdog.arm(platform_api_conn, watchdog_timeout)
2021-08-10T12:04:31.9741648Z remaining_time = watchdog.get_remaining_time(platform_api_conn)
2021-08-10T12:04:31.9743787Z
2021-08-10T12:04:31.9746050Z if self.expect(actual_timeout >= watchdog_timeout, "watchdog arm with {} seconds failed".format(watchdog_timeout)):
2021-08-10T12:04:31.9748793Z if self.expect(remaining_time > 0, "Remaining_time {} seconds is not valid".format(remaining_time)):
2021-08-10T12:04:31.9751780Z self.expect(remaining_time <= actual_timeout, "Remaining_time {} seconds should be less than watchdog armed timeout {} seconds".format(remaining_time, actual_timeout))
2021-08-10T12:04:31.9754325Z
2021-08-10T12:04:31.9756676Z remaining_time = watchdog.get_remaining_time(platform_api_conn)
2021-08-10T12:04:31.9759202Z time.sleep(TEST_WAIT_TIME_SECONDS)
2021-08-10T12:04:31.9761703Z remaining_time_new = watchdog.get_remaining_time(platform_api_conn)
2021-08-10T12:04:31.9764761Z self.expect(remaining_time_new < remaining_time, "Remaining_time {} seconds should be decreased from previous remaining_time {} seconds".format(remaining_time_new, remaining_time))
2021-08-10T12:04:31.9767569Z > self.assert_expectations()
2021-08-10T12:04:31.9768522Z
2021-08-10T12:04:31.9771272Z conf = OrderedDict([('valid_timeout', 10), ('greater_timeout', 100), ('too_big_timeout', 660)])
2021-08-10T12:04:31.9773860Z duthosts = <tests.common.devices.duthosts.DutHosts object at 0x7f76b9ad69d0>
2021-08-10T12:04:31.9776389Z enum_rand_one_per_hwsku_hostname = 'str2-7050cx3-acs-03'
2021-08-10T12:04:31.9778900Z platform_api_conn = <httplib.HTTPConnection instance at 0x7f76a268ed70>
2021-08-10T12:04:31.9781094Z remaining_time = 0
2021-08-10T12:04:31.9782998Z remaining_time_new = 0
2021-08-10T12:04:31.9785288Z self = <test_watchdog.TestWatchdogApi object at 0x7f76b9002550>
2021-08-10T12:04:31.9787666Z watchdog_timeout = 10
2021-08-10T12:04:31.9791924Z
2021-08-10T12:04:31.9793935Z platform_tests/api/test_watchdog.py:143:
2021-08-10T12:04:31.9796277Z _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
2021-08-10T12:04:31.9797461Z
2021-08-10T12:04:31.9799610Z self = <test_watchdog.TestWatchdogApi object at 0x7f76b9002550>
2021-08-10T12:04:31.9800608Z
2021-08-10T12:04:31.9802783Z def assert_expectations(self):
2021-08-10T12:04:31.9804934Z """
2021-08-10T12:04:31.9807357Z Checks if there are any error messages waiting in failed_expectations.
2021-08-10T12:04:31.9810072Z If so, it will fail an assert and pass a concatenation of all pending
2021-08-10T12:04:31.9813776Z error messages. It will also clear failed_expectations to prepare it
2021-08-10T12:04:31.9816027Z for the next use.
2021-08-10T12:04:31.9817990Z """
2021-08-10T12:04:31.9820013Z if len(self.failed_expectations) > 0:
2021-08-10T12:04:31.9822147Z err_msg = ", ".join(self.failed_expectations)
2021-08-10T12:04:31.9825153Z # TODO: When we move to Python 3.3+, we can use self.failed_expectations.clear() instead
2021-08-10T12:04:31.9828500Z del self.failed_expectations[:]
2021-08-10T12:04:31.9830626Z > pytest_assert(False, err_msg)
2021-08-10T12:04:31.9833083Z E Failed: watchdog should be disabled in the initial state, Remaining_time 0 seconds should be decreased from previous remaining_time 0 seconds
2021-08-10T12:04:31.9834185Z
2021-08-10T12:04:31.9837252Z err_msg = 'watchdog should be disabled in the initial state, Remaining_time 0 seconds should be decreased from previous remaining_time 0 seconds'
2021-08-10T12:04:31.9840073Z self = <test_watchdog.TestWatchdogApi object at 0x7f76b9002550>

Describe the results you expected:

platform_tests/api/test_watchdog.py::TestWatchdogApi::test_remaining_time[str2-7050cx3-acs-03] SKIPPED or PASSED

Output of show version:

(paste your output here)

Output of show techsupport:

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Additional information you deem important (e.g. issue happens only occasionally):

[Staphylo]

Our hardware does not have the capability to query remaining time.
On the master branch we ended up implementing a software workaround, but the downside is that it only work from within the same process. If one process monitors while a different one arms the watchdog it won't report accurate information.
I believe we just want to ignore this failure, but I could always cherry-pick our master workaround if you think it's best.