Estoy ejecutando pruebas muy complejas de python-selenium en páginas web no públicas. En la mayoría de los casos, estas pruebas funcionan bien, pero a veces una de estas pruebas falla durante la inicialización del propio controlador web.

Sugerencia: este error ocurre al intentar inicializar un controlador web, es decir, al hacer algo como esto:

# Start of the tests
mydriver =  webdriver.Firefox(firefox_profile=profile, log_path=logfile)
# ERROR HAPPENS HERE

# Doing other stuff here
....
# Doing tests here
....
# Doing shutdown here
mydriver.quit()

Aquí hay un ejemplo completo de tal error:

___________ ERROR at setup of TestSuite.test_synaptic_events_fitting ___________

>   lambda: ihook(item=item, **kwds),
    when=when,
            )

/usr/local/lib/python2.7/dist-packages/flaky/flaky_pytest_plugin.py:273: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
conftest.py:157: in basedriver
    mydriver = firefox.get_driver(*args)
bsp_usecase_tests/tools/firefox.py:44: in get_driver
    driver = webdriver.Firefox(firefox_profile=profile, log_path=logfile)  #### INITIALIZING OF WEBDRIVER HERE
/usr/local/lib/python2.7/dist-packages/selenium/webdriver/firefox/webdriver.py:158: in __init__
    keep_alive=True)
/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py:154: in __init__
    self.start_session(desired_capabilities, browser_profile)
/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py:243: in start_session
    response = self.execute(Command.NEW_SESSION, parameters)
/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/webdriver.py:311: in execute
    self.error_handler.check_response(response)
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 

self = <selenium.webdriver.remote.errorhandler.ErrorHandler object at 0x7efd3b702f90>
response = {'status': 500, 'value': '{"value":{"error":"unknown error","message":"connection refused","stacktrace":"stack backtra...s::imp::thread::{{impl}}::new::thread_start\n                        at /checkout/src/libstd/sys/unix/thread.rs:84"}}'}

    def check_response(self, response):
        """
            Checks that a JSON response from the WebDriver does not have an error.

            :Args:
             - response - The JSON response from the WebDriver server as a dictionary
               object.

            :Raises: If the response contains an error message.
            """
        status = response.get('status', None)
        if status is None or status == ErrorCode.SUCCESS:
            return
        value = None
        message = response.get("message", "")
        screen = response.get("screen", "")
        stacktrace = None
        if isinstance(status, int):
            value_json = response.get('value', None)
            if value_json and isinstance(value_json, basestring):
                import json
                try:
                    value = json.loads(value_json)
                    if len(value.keys()) == 1:
                        value = value['value']
                    status = value.get('error', None)
                    if status is None:
                        status = value["status"]
                        message = value["value"]
                        if not isinstance(message, basestring):
                            value = message
                            message = message.get('message')
                    else:
                        message = value.get('message', None)
                except ValueError:
                    pass

        exception_class = ErrorInResponseException
        if status in ErrorCode.NO_SUCH_ELEMENT:
            exception_class = NoSuchElementException
        elif status in ErrorCode.NO_SUCH_FRAME:
            exception_class = NoSuchFrameException
        elif status in ErrorCode.NO_SUCH_WINDOW:
            exception_class = NoSuchWindowException
        elif status in ErrorCode.STALE_ELEMENT_REFERENCE:
            exception_class = StaleElementReferenceException
        elif status in ErrorCode.ELEMENT_NOT_VISIBLE:
            exception_class = ElementNotVisibleException
        elif status in ErrorCode.INVALID_ELEMENT_STATE:
            exception_class = InvalidElementStateException
        elif status in ErrorCode.INVALID_SELECTOR \
                or status in ErrorCode.INVALID_XPATH_SELECTOR \
                or status in ErrorCode.INVALID_XPATH_SELECTOR_RETURN_TYPER:
            exception_class = InvalidSelectorException
        elif status in ErrorCode.ELEMENT_IS_NOT_SELECTABLE:
            exception_class = ElementNotSelectableException
        elif status in ErrorCode.ELEMENT_NOT_INTERACTABLE:
            exception_class = ElementNotInteractableException
        elif status in ErrorCode.INVALID_COOKIE_DOMAIN:
            exception_class = InvalidCookieDomainException
        elif status in ErrorCode.UNABLE_TO_SET_COOKIE:
            exception_class = UnableToSetCookieException
        elif status in ErrorCode.TIMEOUT:
            exception_class = TimeoutException
        elif status in ErrorCode.SCRIPT_TIMEOUT:
            exception_class = TimeoutException
        elif status in ErrorCode.UNKNOWN_ERROR:
            exception_class = WebDriverException
        elif status in ErrorCode.UNEXPECTED_ALERT_OPEN:
            exception_class = UnexpectedAlertPresentException
        elif status in ErrorCode.NO_ALERT_OPEN:
            exception_class = NoAlertPresentException
        elif status in ErrorCode.IME_NOT_AVAILABLE:
            exception_class = ImeNotAvailableException
        elif status in ErrorCode.IME_ENGINE_ACTIVATION_FAILED:
            exception_class = ImeActivationFailedException
        elif status in ErrorCode.MOVE_TARGET_OUT_OF_BOUNDS:
            exception_class = MoveTargetOutOfBoundsException
        elif status in ErrorCode.JAVASCRIPT_ERROR:
            exception_class = JavascriptException
        elif status in ErrorCode.SESSION_NOT_CREATED:
            exception_class = SessionNotCreatedException
        elif status in ErrorCode.INVALID_ARGUMENT:
            exception_class = InvalidArgumentException
        elif status in ErrorCode.NO_SUCH_COOKIE:
            exception_class = NoSuchCookieException
        elif status in ErrorCode.UNABLE_TO_CAPTURE_SCREEN:
            exception_class = ScreenshotException
        elif status in ErrorCode.ELEMENT_CLICK_INTERCEPTED:
            exception_class = ElementClickInterceptedException
        elif status in ErrorCode.INSECURE_CERTIFICATE:
            exception_class = InsecureCertificateException
        elif status in ErrorCode.INVALID_COORDINATES:
            exception_class = InvalidCoordinatesException
        elif status in ErrorCode.INVALID_SESSION_ID:
            exception_class = InvalidSessionIdException
        elif status in ErrorCode.UNKNOWN_METHOD:
            exception_class = UnknownMethodException
        else:
            exception_class = WebDriverException
        if value == '' or value is None:
            value = response['value']
        if isinstance(value, basestring):
            if exception_class == ErrorInResponseException:
                raise exception_class(response, value)
            raise exception_class(value)
        if message == "" and 'message' in value:
            message = value['message']

        screen = None
        if 'screen' in value:
            screen = value['screen']

        stacktrace = None
        if 'stackTrace' in value and value['stackTrace']:
            stacktrace = []
            try:
                for frame in value['stackTrace']:
                    line = self._value_or_default(frame, 'lineNumber', '')
                    file = self._value_or_default(frame, 'fileName', '<anonymous>')
                    if line:
                        file = "%s:%s" % (file, line)
                    meth = self._value_or_default(frame, 'methodName', '<anonymous>')
                    if 'className' in frame:
                        meth = "%s.%s" % (frame['className'], meth)
                    msg = "    at %s (%s)"
                    msg = msg % (meth, file)
                    stacktrace.append(msg)
            except TypeError:
                pass
        if exception_class == ErrorInResponseException:
            raise exception_class(response, message)
        elif exception_class == UnexpectedAlertPresentException and 'alert' in value:
            raise exception_class(message, screen, stacktrace, value['alert'].get('text'))
>       raise exception_class(message, screen, stacktrace)
E       WebDriverException: Message: connection refused

/usr/local/lib/python2.7/dist-packages/selenium/webdriver/remote/errorhandler.py:237: WebDriverException

Estas pruebas se ejecutan como parte de un plan jenkins dentro de un contenedor acoplable, para garantizar el mismo entorno todo el tiempo. Aquí hay una lista de los paquetes usados y sus versiones:

python 2.7.12pytest 3.6.1selenium 3.8.0geckodriver 0.19.1firefox 62.0flaky 3.4.0

El error aparece aproximadamente en aproximadamente el 1% de todas las pruebas. Hay alrededor de 15 pruebas diferentes, y el error parece aparecer al azar (es decir, no siempre la misma prueba).

¿Es esto un error en firefox / selenium / geckodriver? ¿Y hay alguna manera de arreglar esto?

El siguiente fragmento de código no es un código que estoy usando! Es solo una idea de cómo solucionar mi problema descrito anteriormente. ¿Es esta una buena forma de resolver mi problema original o no?

while counter<5:
    try:
        webdriver = webdriver.Firefox(firefox_profile=profile, log_path=logfile) 
        break
    except WebDriverException:
        counter +=1

¿Hay una mejor manera de hacer esto