Update pylint to work with python 3

The pylint job was switched over to run under python 3, but
the job is not voting and it was apparently missed that the
conversion was causing it to fail.

This updates the version of pylint to one that is actually
supported by python 3 and makes tweaks to our script to
for the minor changes between versions.

Single character change to get rid of the more strict py3
regex string escape character format.

Change-Id: I93124b62c5ee177815457b32f55f5453fc3d387e
Signed-off-by: Sean McGinnis <sean.mcginnis@gmail.com>

.gitignore

@@ -16,3 +16,7 @@ build
 dist
 cinderclient/versioninfo
 python_cinderclient.egg-info
+
+# pylint files
+tools/lintstack.head.py
+tools/pylint_exceptions

cinderclient/client.py

@@ -69,7 +69,7 @@ REQ_ID_HEADER = 'X-OpenStack-Request-ID'
 # tell keystoneclient that we can ignore the /v1|v2/{project_id} component of
 # the service catalog when doing discovery lookups
 for svc in ('volume', 'volumev2', 'volumev3'):
-    discover.add_catalog_discover_hack(svc, re.compile('/v[12]/\w+/?$'), '/')
+    discover.add_catalog_discover_hack(svc, re.compile(r'/v[12]/\w+/?$'), '/')
 
 
 def get_server_version(url):

tools/lintstack.py

@@ -16,8 +16,6 @@
 
 """pylint error checking."""
 
-from __future__ import print_function
-
 import json
 import re
 import sys
@@ -70,6 +68,8 @@ class LintOutput(object):
     @classmethod
     def from_line(cls, line):
         m = re.search(r"(\S+):(\d+): \[(\S+)(, \S+)?] (.*)", line)
+        if m is None:
+            return None
         matched = m.groups()
         filename, lineno, code, message = (matched[0], int(matched[1]),
                                            matched[2], matched[-1])
@@ -83,13 +83,15 @@ class LintOutput(object):
 
     @classmethod
     def from_msg_to_dict(cls, msg):
-        """From the output of pylint msg, to a dict, where each key
+        """Convert pylint output to a dict.
+
+        From the output of pylint msg, to a dict, where each key
         is a unique error identifier, value is a list of LintOutput
         """
         result = {}
         for line in msg.splitlines():
             obj = cls.from_line(line)
-            if obj.is_ignored():
+            if obj is None or obj.is_ignored():
                 continue
             key = obj.key()
             if key not in result:
@@ -147,8 +149,10 @@ class ErrorKeys(object):
 
 def run_pylint():
     buff = StringIO()
-    reporter = text.ParseableTextReporter(output=buff)
-    args = ["--include-ids=y", "-E", "cinderclient"]
+    reporter = text.TextReporter(output=buff)
+    args = [
+        "--msg-template='{path}:{line}: [{msg_id}({symbol}), {obj}] {msg}'",
+        "-E", "cinderclient"]
     lint.Run(args, reporter=reporter, exit=False)
     val = buff.getvalue()
     buff.close()

tox.ini

@@ -33,7 +33,7 @@ basepython = python3
 deps =
   -c{env:UPPER_CONSTRAINTS_FILE:https://git.openstack.org/cgit/openstack/requirements/plain/upper-constraints.txt}
   -r{toxinidir}/requirements.txt
-       pylint==0.26.0
+       pylint==1.9.1
 commands = bash tools/lintstack.sh
 whitelist_externals = bash