Fix broken pep8 exclude processing.

First of all, our pep8 exclude was excluding openstack, to trap
for not doing pep8 checks on openstack/common, which comes from elsewhere.
But, pep8 strips filenames down to basename when doing exclude checks on
them, which makes no sense. To fix this, grab the two functions from pep8,
fix them, and monkeypatch them from within hacking.py.

Patch has been submitted upstream as:

  https://github.com/jcrocholl/pep8/pull/111

Also, changed the exclude to catch just openstack/common.

Change-Id: If0b18ae828e74203f84a8b6f8b4ba0100b3bbc59

tools/hacking.py

@@ -21,6 +21,7 @@
 built on top of pep8.py
 """
 
+import fnmatch
 import inspect
 import logging
 import os
@@ -49,6 +50,52 @@ DOCSTRING_TRIPLE = ['"""', "'''"]
 VERBOSE_MISSING_IMPORT = False
 
 
+# Monkey patch broken excluded filter in pep8
+def filename_match(filename, patterns, default=True):
+    """
+    Check if patterns contains a pattern that matches filename.
+    If patterns is unspecified, this always returns True.
+    """
+    if not patterns:
+        return default
+    return any(fnmatch.fnmatch(filename, pattern) for pattern in patterns)
+
+
+def excluded(filename):
+    """
+    Check if options.exclude contains a pattern that matches filename.
+    """
+    basename = os.path.basename(filename)
+    return any((filename_match(filename, pep8.options.exclude,
+                               default=False),
+                filename_match(basename, pep8.options.exclude,
+                               default=False)))
+
+
+def input_dir(dirname, runner=None):
+    """
+    Check all Python source files in this directory and all subdirectories.
+    """
+    dirname = dirname.rstrip('/')
+    if excluded(dirname):
+        return
+    if runner is None:
+        runner = pep8.input_file
+    for root, dirs, files in os.walk(dirname):
+        if pep8.options.verbose:
+            print('directory ' + root)
+        pep8.options.counters['directories'] += 1
+        dirs.sort()
+        for subdir in dirs[:]:
+            if excluded(os.path.join(root, subdir)):
+                dirs.remove(subdir)
+        files.sort()
+        for filename in files:
+            if pep8.filename_match(filename) and not excluded(filename):
+                pep8.options.counters['files'] += 1
+                runner(os.path.join(root, filename))
+
+
 def is_import_exception(mod):
     return (mod in IMPORT_EXCEPTIONS or
             any(mod.startswith(m + '.') for m in IMPORT_EXCEPTIONS))
@@ -417,6 +464,8 @@ if __name__ == "__main__":
     add_nova()
     pep8.current_file = current_file
     pep8.readlines = readlines
+    pep8.excluded = excluded
+    pep8.input_dir = input_dir
     try:
         pep8._main()
     finally:

tox.ini

@@ -17,7 +17,10 @@ commands = nosetests {posargs}
 downloadcache = ~/cache/pip
 
 [testenv:pep8]
-commands = python tools/hacking.py --ignore=N4 --repeat --show-source --exclude=.venv,.tox,dist,doc,openstack,*egg .
+deps=pep8==1.0.1
+commands =
+  python tools/hacking.py --ignore=N4 --repeat --show-source \
+    --exclude=.venv,.tox,dist,doc,*openstack/common*,*lib/python*,*egg .
 
 [testenv:cover]
 setenv = NOSE_WITH_COVERAGE=1