validation_output.py: Provided output for ansible debug module.

- prints both variables and messages provided to the module
- template for printing debug module results created
- output contains module name, host and the result

Change-Id: I5854256542951d09bd48fa0e9415b90fd67abce8

validations/callback_plugins/validation_output.py

@@ -34,6 +34,12 @@ Host: {}
 Warnings:
 """
 
+DEBUG_TEMPLATE = """\
+Task: Debug
+Host: {}
+{}
+"""
+
 
 def indent(text):
     '''Indent the given text by four spaces.'''
@@ -114,6 +120,28 @@ class CallbackModule(CallbackBase):
             for warning in warnings:
                 print("*", warning)
 
+        # Print the result of debug module
+        if (('invocation' in results) and
+           ('module_name' in results['invocation'])):
+
+            if ((results['invocation']['module_name'] == 'debug') and
+               ('module_args' in results['invocation'])):
+
+                output = ""
+
+                # Variable and its value
+                if 'var' in results['invocation']['module_args']:
+                    variable = results['invocation']['module_args']['var']
+                    value = results[variable]
+                    output = "{}: {}".format(variable, str(value))
+
+                # Debug message
+                elif 'msg' in results['invocation']['module_args']:
+                    output = "Message: {}".format(
+                             results['invocation']['module_args']['msg'])
+
+                print(DEBUG_TEMPLATE.format(host_name, output))
+
     def v2_runner_on_failed(self, result, **kwargs):
         host_name = result._host
         task_name = result._task.get_name()