Switch to os.system instead of subprocess which is not thread-safe

ironic_discoverd/discoverd.py

@@ -1,7 +1,7 @@
 import ConfigParser
 import logging
+import os
 import re
-from subprocess import call, check_call
 import threading
 
 from ironicclient import client, exceptions
@@ -139,20 +139,15 @@ class Firewall(object):
 
     @staticmethod
     def _iptables(*args, **kwargs):
-        cmd = ('iptables',) + args
+        cmd = ' '.join(('iptables',) + args)
         LOG.debug('Running iptables %s', args)
-        if kwargs.pop('ignore', False):
-            if call(cmd, **kwargs):
-                LOG.warn('iptables failed: %s', args)
-                return False
+        # Would use subprocess if it was thread-safe
+        if os.system(cmd):
+            if not kwargs.pop('ignore', False):
+                raise RuntimeError('Failed to execute iptables %s' %
+                                   list(args))
             else:
-                return True
-        else:
-            try:
-                return check_call(cmd, **kwargs)
-            except Exception:
-                LOG.error('iptables failed: %s', args)
-                raise
+                LOG.warn('iptables failed: %s', args)
 
     @classmethod
     def init(cls):