Move diff code more into runner code.

lib/ansible/callbacks.py

@@ -219,6 +219,7 @@ class DefaultRunnerCallbacks(object):
         call_callback_module('runner_on_async_failed', host, res, jid)
 
     def on_file_diff(self, host, before_string, after_string):
+        if before_string and after_string:
             call_callback_module('runner_on_file_diff', before_string, after_string)
 
 ########################################################################
@@ -286,6 +287,7 @@ class CliRunnerCallbacks(DefaultRunnerCallbacks):
             utils.write_tree_file(self.options.tree, host, utils.jsonify(result2,format=True))
     
     def on_file_diff(self, host, before_string, after_string):
+        if before_string and after_string:
             if self.options.diff:
                 print utils.get_diff(before_string, after_string)
             super(CliRunnerCallbacks, self).on_file_diff(host, before_string, after_string)
@@ -422,6 +424,7 @@ class PlaybookRunnerCallbacks(DefaultRunnerCallbacks):
         super(PlaybookRunnerCallbacks, self).on_async_failed(host,res,jid)
 
     def on_file_diff(self, host, before_string, after_string):
+        if before_string and after_string:
             print utils.get_diff(before_string, after_string)
             super(PlaybookRunnerCallbacks, self).on_file_diff(host, before_string, after_string)
 

lib/ansible/runner/__init__.py

@@ -449,6 +449,8 @@ class Runner(object):
                 ignore_errors = self.module_vars.get('ignore_errors', False)
                 self.callbacks.on_failed(host, data, ignore_errors)
             else:
+                if self.diff:
+                    self.callbacks.on_file_diff(conn.host, result.before_diff_value, result.after_diff_value)
                 self.callbacks.on_ok(host, data)
         return result
 

lib/ansible/runner/action_plugins/template.py

@@ -83,14 +83,18 @@ class ActionModule(object):
 
              # if showing diffs, we need to get the remote value
              dest_contents = None
+
              if self.runner.diff:
                  # using persist_files to keep the temp directory around to avoid needing to grab another
                  dest_result = self.runner._execute_module(conn, tmp, 'slurp', "path=%s" % dest, inject=inject, persist_files=True)
+                 if 'content' in dest_result.result:
                      dest_contents = dest_result.result['content']
                      if dest_result.result['encoding'] == 'base64':
                          dest_contents = base64.b64decode(dest_contents)
                      else:
                          raise Exception("unknown encoding, failed: %s" % dest_result.result)
+                 else:
+                     dest_result = ''
  
              xfered = self.runner._transfer_str(conn, tmp, 'source', resultant)
 
@@ -102,13 +106,11 @@ class ActionModule(object):
              module_args = "%s src=%s dest=%s" % (module_args, xfered, dest)
 
              if self.runner.check:
-                 if self.runner.diff:
-                     self.runner.callbacks.on_file_diff(conn.host, dest_contents, resultant)
-                 return ReturnData(conn=conn, comm_ok=True, result=dict(changed=True))
+                 return ReturnData(conn=conn, comm_ok=True, result=dict(changed=True), before_diff_value=dest_contents, after_diff_value=resultant)
              else:
                  res =  self.runner._execute_module(conn, tmp, 'copy', module_args, inject=inject)
-                 if self.runner.diff:
-                     self.runner.callbacks.on_file_diff(conn.host, dest_contents, resultant)
+                 res.before_diff_value = dest_contents
+                 res.after_diff_value = resultant
                  return res
         else:
              return ReturnData(conn=conn, comm_ok=True, result=dict(changed=False))

lib/ansible/runner/return_data.py

@@ -20,9 +20,10 @@ from ansible import utils
 class ReturnData(object):
     ''' internal return class for runner execute methods, not part of public API signature '''
 
-    __slots__ = [ 'result', 'comm_ok', 'host' ]
+    __slots__ = [ 'result', 'comm_ok', 'host', 'before_diff_value', 'after_diff_value' ]
 
-    def __init__(self, conn=None, host=None, result=None, comm_ok=True):
+    def __init__(self, conn=None, host=None, result=None, 
+        comm_ok=True, before_diff_value=None, after_diff_value=None):
 
         # which host is this ReturnData about?
         if conn is not None:
@@ -38,6 +39,11 @@ class ReturnData(object):
         self.result = result
         self.comm_ok = comm_ok
 
+        # if these values are set and used with --diff we can show
+        # changes made to particular files
+        self.before_diff_value = before_diff_value
+        self.after_diff_value = after_diff_value
+
         if type(self.result) in [ str, unicode ]:
             self.result = utils.parse_json(self.result)