Provide diagnostic messages about netrc failures.

gerrit_util.py

 # Copyright (c) 2013 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """
 Utilities for requesting information for a gerrit server via https.
 
 https://gerrit-review.googlesource.com/Documentation/rest-api.html
 """
 
 import base64
 import httplib
 import json
 import logging
 import netrc
 import os
 import re
+import stat
+import sys
 import time
 import urllib
 from cStringIO import StringIO
 
+_netrc_file = '_netrc' if sys.platform.startswith('win') else '.netrc'
+_netrc_file = os.path.join(os.environ['HOME'], _netrc_file)
 try:
-  NETRC = netrc.netrc()
-except (IOError, netrc.NetrcParseError):
+  NETRC = netrc.netrc(_netrc_file)
+except IOError:
+  print >> sys.stderr, 'WARNING: Could not read netrc file %s' % _netrc_file
   NETRC = netrc.netrc(os.devnull)
+except netrc.NetrcParseError as e:
+  _netrc_stat = os.stat(e.filename)
+  if _netrc_stat.st_mode & (stat.S_IRWXG | stat.S_IRWXO):
+    print >> sys.stderr, (
+        'WARNING: netrc file %s cannot be used because its file permissions '
+        'are insecure.  netrc file permissions should be 600.' % _netrc_file)
+  else:
+    print >> sys.stderr, ('ERROR: Cannot use netrc file %s due to a parsing '
+                          'error.' % _netrc_file)
+    raise
+  del _netrc_stat
+  NETRC = netrc.netrc(os.devnull)
+del _netrc_file
+
 LOGGER = logging.getLogger()
 TRY_LIMIT = 5
 
 # Controls the transport protocol used to communicate with gerrit.
 # This is parameterized primarily to enable GerritTestCase.
 GERRIT_PROTOCOL = 'https'
 
 
 class GerritError(Exception):
   """Exception class for errors commuicating with the gerrit-on-borg service."""
@@ skipping 410 matching lines @@
         username = review.get('email', jmsg.get('name', ''))
         raise GerritError(200, 'Unable to set %s label for user "%s"'
                        ' on change %s.' % (label, username, change))
   jmsg = GetChangeCurrentRevision(host, change)
   if not jmsg:
     raise GerritError(
         200, 'Could not get review information for change "%s"' % change)
   elif jmsg[0]['current_revision'] != revision:
     raise GerritError(200, 'While resetting labels on change "%s", '
                    'a new patchset was uploaded.' % change)