diff --git a/action_plugins/postconf.py b/action_plugins/postconf.py
index 5a7b9dd..ec92ff4 100755
--- a/action_plugins/postconf.py
+++ b/action_plugins/postconf.py
@@ -43,28 +43,31 @@ class ActionModule(ActionBase):
                 return '{}'.format(self._task.args.get(key, ''))
             if key in ('private', 'unprivileged', 'chroot', 'wakeup', 'process_limit'):
                 return '{}'.format(self._task.args.get(key, ''))
+            if key == 'container_name':
+                return '{}'.format(self._task.args.get(key, 'postfix'))
         # no default value for key: return as-is
         return self._task.args.get(key)
 
 
     def runcmd(self, reg_name, cmd, param=None):
+        fullcmd = 'docker exec '+ self.getarg('container_name') + cmd
         try:
             if param:
                 self.reg[param][reg_name] = self._execute_module(
                     module_name='command',
-                    module_args=dict(_raw_params=cmd)
+                    module_args=dict(_raw_params=fullcmd)
                 )
                 return
             self.reg[reg_name] = self._execute_module(
                 module_name='command',
-                module_args=dict(_raw_params=cmd)
+                module_args=dict(_raw_params=fullcmd)
             )
         except Exception as e:
             raise PfWorkflowError(
                 "{}: {}; failed command line: {}".format(
                     type(e).__name__,
                     to_text(e),
-                    cmd
+                    fullcmd
                 )
             )