Python 3 Fixes: Replace missing builtins

There are a few different missing builtins in python3 that we're using.
This shows up when running tox pep8 under python3 which is needed for
the streamer work.

Change-Id: I1b2ef0b7bdcd1a85895576682455745fe06e880b

tests/base.py

@@ -27,6 +27,7 @@ import random
 import re
 import select
 import shutil
+from six.moves import reload_module
 import socket
 import string
 import subprocess
@@ -916,8 +917,8 @@ class ZuulTestCase(BaseTestCase):
         os.environ['STATSD_PORT'] = str(self.statsd.port)
         self.statsd.start()
         # the statsd client object is configured in the statsd module import
-        reload(statsd)
-        reload(zuul.scheduler)
+        reload_module(statsd)
+        reload_module(zuul.scheduler)
 
         self.gearman_server = FakeGearmanServer()
 

tox.ini

@@ -18,6 +18,8 @@ commands =
   python setup.py testr --slowest --testr-args='{posargs}'
 
 [testenv:pep8]
+# streamer is python3 only, so we need to run flake8 in python3
+basepython = python3
 commands = flake8 {posargs}
 
 [testenv:cover]

zuul/launcher/gearman.py

@@ -17,6 +17,7 @@ import inspect
 import json
 import logging
 import os
+import six
 import time
 import threading
 from uuid import uuid4
@@ -231,7 +232,7 @@ class Gearman(object):
                 s_config = {}
                 s_config.update((k, v.format(item=item, job=job,
                                              change=item.change))
-                                if isinstance(v, basestring)
+                                if isinstance(v, six.string_types)
                                 else (k, v)
                                 for k, v in s.items())
 

zuul/model.py

@@ -110,7 +110,11 @@ class Pipeline(object):
         return job_tree
 
     def getProjects(self):
-        return sorted(self.job_trees.keys(), lambda a, b: cmp(a.name, b.name))
+        # cmp is not in python3, applied idiom from
+        # http://python-future.org/compatible_idioms.html#cmp
+        return sorted(
+            self.job_trees.keys(),
+            key=lambda p: p.name)
 
     def addQueue(self, queue):
         self.queues.append(queue)

zuul/scheduler.py

@@ -411,7 +411,9 @@ class Scheduler(threading.Thread):
                     base = os.path.dirname(os.path.realpath(config_path))
                     fn = os.path.join(base, fn)
                 fn = os.path.expanduser(fn)
-                execfile(fn, config_env)
+                with open(fn) as _f:
+                    code = compile(_f.read(), fn, 'exec')
+                    six.exec_(code, config_env)
 
         for conf_pipeline in data.get('pipelines', []):
             pipeline = Pipeline(conf_pipeline['name'])