'shell' is a magic module that executes the command module with shell=True

lib/ansible/runner.py

@@ -308,6 +308,12 @@ class Runner(object):
         because those require extra work.
         '''
 
+        # hack to make the 'shell' module keyword really be executed
+        # by the command module
+        if self.module_name == 'shell':
+            self.module_name = 'command'
+            self.module_args.append("#USE_SHELL")
+
         module = self._transfer_module(conn, tmp, self.module_name)
         result = self._execute_module(conn, tmp, module, self.module_args)
 

lib/ansible/utils.py

@@ -120,7 +120,7 @@ def host_report_msg(hostname, module_name, result, oneline):
     ''' summarize the JSON results for a particular host '''
     buf = ''
     failed = is_failed(result)
-    if module_name == 'command':
+    if module_name in [ 'command', 'shell' ]:
         if not failed:
             buf = command_success_msg(hostname, result, oneline)
         else: