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/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)