Scrape and submit metrics from cadvisor
        :param: instance: check instance object
        :param: cadvisor_url: valid cadvisor url, as returned by detect_cadvisor()
        :param: pod_list: fresh podlist object from the kubelet
        :param: pod_list_utils: already initialised PodListUtils object

def process_cadvisor(self, instance, cadvisor_url, pod_list, pod_list_utils):
        """
        Scrape and submit metrics from cadvisor
        :param: instance: check instance object
        :param: cadvisor_url: valid cadvisor url, as returned by detect_cadvisor()
        :param: pod_list: fresh podlist object from the kubelet
        :param: pod_list_utils: already initialised PodListUtils object
        """
        self.max_depth = instance.get('max_depth', DEFAULT_MAX_DEPTH)
        enabled_gauges = instance.get('enabled_gauges', DEFAULT_ENABLED_GAUGES)
        self.enabled_gauges = ["{0}.{1}".format(NAMESPACE, x) for x in enabled_gauges]
        enabled_rates = instance.get('enabled_rates', DEFAULT_ENABLED_RATES)
        self.enabled_rates = ["{0}.{1}".format(NAMESPACE, x) for x in enabled_rates]
        pod_level_metrics = instance.get('pod_level_metrics', DEFAULT_POD_LEVEL_METRICS)
        self.pod_level_metrics = ["{0}.{1}".format(NAMESPACE, x) for x in pod_level_metrics]

        self._update_metrics(instance, cadvisor_url, pod_list, pod_list_utils)