Add network check methods to Device and Workload classes

- Device subclasses should provide their own implementation.
    Default behaviour is to raise a `NotImplementedError`
  - Workload subclasses can set `requires_network` to `True` and
    network connectivity check will be performed during `setup()`

wlauto/common/android/workload.py

@@ -86,6 +86,7 @@ class UiAutomatorWorkload(Workload):
             self.uiauto_package = os.path.splitext(os.path.basename(self.uiauto_file))[0]
 
     def setup(self, context):
+        super(UiAutomatorWorkload, self).setup(context)
         method_string = '{}.{}#{}'.format(self.uiauto_package, self.uiauto_class, self.uiauto_method)
         params_dict = self.uiauto_params
         params_dict['workdir'] = self.device.working_directory
@@ -179,6 +180,7 @@ class ApkWorkload(Workload):
         self.logcat_log = None
 
     def setup(self, context):
+        super(ApkWorkload, self).setup(context)
         # Get APK for the correct version and device ABI
         self.apk_file = context.resolver.get(ApkFile(self, self.device.abi),
                                              version=getattr(self, 'version', None),
@@ -363,6 +365,7 @@ class ReventWorkload(Workload):
         self.run_timeout = self.run_timeout or default_run_timeout
 
     def setup(self, context):
+        super(ReventWorkload, self).setup(context)
         self.device.killall('revent')
         command = '{} replay {}'.format(self.on_device_revent_binary, self.on_device_setup_revent)
         self.device.execute(command, timeout=self.setup_timeout)

wlauto/common/linux/device.py

@@ -39,6 +39,8 @@ FstabEntry = namedtuple('FstabEntry', ['device', 'mount_point', 'fs_type', 'opti
 PsEntry = namedtuple('PsEntry', 'user pid ppid vsize rss wchan pc state name')
 LsmodEntry = namedtuple('LsmodEntry', ['name', 'size', 'use_count', 'used_by'])
 
+GOOGLE_DNS_SERVER_ADDRESS = '8.8.8.8'
+
 
 class BaseLinuxDevice(Device):  # pylint: disable=abstract-method
 
@@ -318,25 +320,28 @@ class BaseLinuxDevice(Device):  # pylint: disable=abstract-method
 
             please see: https://pythonhosted.org/wlauto/writing_extensions.html""")
 
-    def is_network_connected(self, ip_address='8.8.8.8'):
+    def is_network_connected(self):
         """
-        Checks for internet connectivity on the device
-        by pinging IP address provided.
+        Checks for internet connectivity on the device by pinging IP address provided.
 
-        :param ip_address: the IP address to ping
-                           (default - google-public-dns-a.google.com)
+        :param ip_address: IP address to ping. Default is Google's public DNS server (8.8.8.8)
+
+        :returns: ``True`` if internet is available, ``False`` otherwise.
 
         """
-        self.logger.debug('Checking for internet connectivity.')
-        output = self.execute('ping -q -w 1 -c 1 {}'.format(ip_address),
+        self.logger.debug('Checking for internet connectivity...')
+        return self._ping_server(GOOGLE_DNS_SERVER_ADDRESS)
+
+    def _ping_server(self, ip_address, timeout=1, packet_count=1):
+        output = self.execute('ping -q -c {} -w {} {}'.format(packet_count, timeout, ip_address),
                               check_exit_code=False)
 
-        if 'network is unreachable' not in output.lower():
-            self.logger.debug('Found IP address {}'.format(ip_address))
-            return True
-        else:
+        if 'network is unreachable' in output.lower():
             self.logger.debug('Cannot find IP address {}'.format(ip_address))
             return False
+        else:
+            self.logger.debug('Found IP address {}'.format(ip_address))
+            return True
 
     def get_binary_path(self, name, search_system_binaries=True):
         """

wlauto/core/device.py

@@ -426,6 +426,13 @@ class Device(Extension):
         """
         pass
 
+    def is_network_connected(self):
+        """
+        Checks if the device is connected to the internet
+
+        """
+        raise NotImplementedError()
+
     def __str__(self):
         return 'Device<{}>'.format(self.name)
 

wlauto/core/workload.py

@@ -37,6 +37,7 @@ class Workload(Extension):
     supported_devices = []
     supported_platforms = []
     summary_metrics = []
+    requires_network = False
 
     def __init__(self, device, **kwargs):
         """
@@ -69,7 +70,7 @@ class Workload(Extension):
         """
         pass
 
-    def setup(self, context):
+    def setup(self, context):  # pylint: disable=unused-argument
         """
         Perform the setup necessary to run the workload, such as copying the necessary files
         to the device, configuring the environments, etc.
@@ -78,7 +79,8 @@ class Workload(Extension):
         the workload.
 
         """
-        pass
+        if self.requires_network:
+            self.check_network_connected()
 
     def run(self, context):
         """Execute the workload. This is the method that performs the actual "work" of the"""
@@ -99,5 +101,10 @@ class Workload(Extension):
     def finalize(self, context):
         pass
 
+    def check_network_connected(self):
+        if not self.device.is_network_connected():
+            message = 'Workload "{}" requires internet. Device "{}" does not appear to be connected to the internet.'
+            raise WorkloadError(message.format(self.name, self.device.name))
+
     def __str__(self):
         return '<Workload {}>'.format(self.name)