Remove final six usage

We also update docs since guidance has necessarily changed here.

Change-Id: I7c24a1aa3545f3499a7a2ce30b73e2656666c764
Signed-off-by: Stephen Finucane <sfinucan@redhat.com>

doc/source/contributor/gerrit.rst

@@ -26,38 +26,9 @@ The Great Change
 
 With the demise of Python 2.7 in January 2020, beginning with the Ussuri
 development cycle, Glance only needs to support Python 3 runtimes (in
-particular, 3.6 and 3.7).  Thus we can begin to incorporate Python 3
+particular, 3.6 and 3.7).  There was a four cycle transition period, but
-language features and remove Python 2 compatibility code.  At the same
+starting in the Yoga development cycle, all Python 2 compatibility code
-time, however, we are still supporting stable branches that must support
+has been removed and only Python 3 is supposed.
-Python 2.  Our biggest interaction with the stable branches is backporting
-bugfixes, where in the ideal case, we're just doing a simple cherry-pick of
-a commit from master to the stable branches.  You can see that there's some
-tension here.
-
-With that in mind, here are some guidelines for reviewers and developers
-that the Glance community has agreed on during this phase where we want to
-write pure Python 3 but still must support Python 2 code.
-
-.. _transition-guidelines:
-
-Python 2 to Python 3 transition guidelines
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-
-* We need to be checking the code coverage of test cases very carefully so
-  that new code has excellent coverage.  The idea is that we want these
-  tests to fail when a backport is proposed to a stable branch and the
-  tests are run under Python 2 (if the code is using any Python-3-only
-  language features).
-* New features can use Python-3-only language constructs, but bugfixes
-  likely to be backported should be more conservative and write for
-  Python 2 compatibility.
-* The code for drivers may continue to use the six compatibility library at
-  their discretion.
-* We will not remove six from mainline Cinder code that impacts the drivers
-  (for example, classes they inherit from).
-* We can remove six from code that doesn't impact drivers, keeping in mind
-  that backports may be more problematic, and hence making sure that we have
-  really good test coverage.
 
 Unit Tests
 ----------

glance/api/middleware/cache.py

@@ -24,7 +24,6 @@ the local cached copy of the image file is returned.
 
 import http.client as http
 import re
-import six
 
 from oslo_log import log as logging
 import webob
@@ -220,8 +219,7 @@ class CacheFilter(wsgi.Middleware):
         # https://github.com/Pylons/webob/issues/86
         response.headers['Content-Type'] = 'application/octet-stream'
         if image.checksum:
-            response.headers['Content-MD5'] = (image.checksum.encode('utf-8')
+            response.headers['Content-MD5'] = image.checksum
-                                               if six.PY2 else image.checksum)
         response.headers['Content-Length'] = str(image.size)
         return response
 

glance/api/v2/tasks.py

@@ -25,7 +25,6 @@ from oslo_log import log as logging
 import oslo_serialization.jsonutils as json
 from oslo_utils import encodeutils
 from oslo_utils import uuidutils
-import six
 import webob.exc
 
 from glance.api import common
@@ -270,8 +269,6 @@ class ResponseSerializer(wsgi.JSONResponseSerializer):
 
     def _inject_location_header(self, response, task):
         location = self._get_task_location(task)
-        if six.PY2:
-            location = location.encode('utf-8')
         response.headers['Location'] = location
 
     def _get_task_location(self, task):

glance/cmd/replicator.py

@@ -26,7 +26,6 @@ from oslo_log import log as logging
 from oslo_serialization import jsonutils
 from oslo_utils import encodeutils
 from oslo_utils import uuidutils
-import six
 from webob import exc
 
 from glance.common import config
@@ -395,11 +394,7 @@ def replication_dump(options, args):
                       'data_filename': data_filename})
 
             # Dump glance information
-            if six.PY3:
+            with open(data_path, 'w', encoding='utf-8') as f:
-                f = open(data_path, 'w', encoding='utf-8')
-            else:
-                f = open(data_path, 'w')
-            with f:
                 f.write(jsonutils.dumps(image))
 
             if image['status'] == 'active' and not options.metaonly:

glance/common/client.py

@@ -44,7 +44,6 @@ except ImportError:
 from oslo_log import log as logging
 from oslo_utils import encodeutils
 from oslo_utils import netutils
-import six
 
 from glance.common import auth
 from glance.common import exception
@@ -411,11 +410,7 @@ class BaseClient(object):
         :returns: Dictionary with encoded headers'
                   names and values
         """
-        if six.PY3:
+        return {str(h): str(v) for h, v in headers.items()}
-            to_str = str
-        else:
-            to_str = encodeutils.safe_encode
-        return {to_str(h): to_str(v) for h, v in headers.items()}
 
     @handle_redirects
     def _do_request(self, method, url, body, headers):
@@ -512,9 +507,7 @@ class BaseClient(object):
                 return res.getheader('Retry-After')
 
             def read_body(res):
-                body = res.read()
+                body = res.read().decode('utf-8')
-                if six.PY3:
-                    body = body.decode('utf-8')
                 return body
 
             status_code = self.get_status_code(res)

glance/common/crypt.py

@@ -26,7 +26,6 @@ from cryptography.hazmat.primitives.ciphers import algorithms
 from cryptography.hazmat.primitives.ciphers import Cipher
 from cryptography.hazmat.primitives.ciphers import modes
 from oslo_utils import encodeutils
-import six
 
 
 def urlsafe_encrypt(key, plaintext, blocksize=16):
@@ -48,7 +47,7 @@ def urlsafe_encrypt(key, plaintext, blocksize=16):
         # NOTE(rosmaita): I know this looks stupid, but we can't just
         # use os.urandom() to get the bytes because we use char(0) as
         # a delimiter
-        pad = b''.join(six.int2byte(random.SystemRandom().randint(1, 0xFF))
+        pad = b''.join(bytes((random.SystemRandom().randint(1, 0xFF),))
                        for i in range(pad_length - 1))
         # We use chr(0) as a delimiter between text and padding
         return text + b'\0' + pad
@@ -63,7 +62,6 @@ def urlsafe_encrypt(key, plaintext, blocksize=16):
     encryptor = cypher.encryptor()
     padded = encryptor.update(pad(plaintext)) + encryptor.finalize()
     encoded = base64.urlsafe_b64encode(init_vector + padded)
-    if six.PY3:
     encoded = encoded.decode('ascii')
     return encoded
 
@@ -88,6 +86,5 @@ def urlsafe_decrypt(key, ciphertext):
     decryptor = cypher.decryptor()
     padded = decryptor.update(ciphertext[16:]) + decryptor.finalize()
     text = padded[:padded.rfind(b'\0')]
-    if six.PY3:
     text = text.decode('utf-8')
     return text

glance/common/utils.py

@@ -39,7 +39,6 @@ from oslo_log import log as logging
 from oslo_utils import excutils
 from oslo_utils import netutils
 from oslo_utils import strutils
-import six
 from webob import exc
 
 from glance.common import exception
@@ -443,8 +442,6 @@ def get_test_suite_socket():
     if GLANCE_TEST_SOCKET_FD_STR in os.environ:
         fd = int(os.environ[GLANCE_TEST_SOCKET_FD_STR])
         sock = socket.fromfd(fd, socket.AF_INET, socket.SOCK_STREAM)
-        if six.PY2:
-            sock = socket.SocketType(_sock=sock)
         sock.listen(CONF.backlog)
         del os.environ[GLANCE_TEST_SOCKET_FD_STR]
         os.close(fd)

glance/common/wsgi.py

@@ -45,7 +45,6 @@ from oslo_utils import encodeutils
 from oslo_utils import strutils
 from osprofiler import opts as profiler_opts
 import routes.middleware
-import six
 import webob.dec
 import webob.exc
 from webob import multidict
@@ -1104,26 +1103,6 @@ class Request(webob.Request):
         # not be inherited.
         webob.Request.body_file.fset(self, value)
 
-    @property
-    def params(self):
-        """Override params property of webob.request.BaseRequest.
-
-        Added an 'encoded_params' attribute in case of PY2 to avoid
-        encoding values in next subsequent calls to the params property.
-        """
-        if six.PY2:
-            encoded_params = getattr(self, 'encoded_params', None)
-            if encoded_params is None:
-                params = super(Request, self).params
-                params_dict = multidict.MultiDict()
-                for key, value in params.items():
-                    params_dict.add(key, encodeutils.safe_encode(value))
-
-                setattr(self, 'encoded_params',
-                        multidict.NestedMultiDict(params_dict))
-            return self.encoded_params
-        return super(Request, self).params
-
     def best_match_content_type(self):
         """Determine the requested response content-type."""
         supported = ('application/json',)
@@ -1352,9 +1331,8 @@ class Resource(object):
             action_result = self.dispatch(self.controller, action,
                                           request, **action_args)
         except webob.exc.WSGIHTTPException as e:
-            exc_info = sys.exc_info()
             e = translate_exception(request, e)
-            six.reraise(type(e), e, exc_info[2])
+            raise e.with_traceback(sys.exc_info()[2])
         except UnicodeDecodeError:
             msg = _("Error decoding your request. Either the URL or the "
                     "request body contained characters that could not be "
@@ -1373,10 +1351,6 @@ class Resource(object):
         try:
             response = webob.Response(request=request)
             self.dispatch(self.serializer, action, response, action_result)
-            # encode all headers in response to utf-8 to prevent unicode errors
-            for name, value in list(response.headers.items()):
-                if six.PY2 and isinstance(value, str):
-                    response.headers[name] = encodeutils.safe_encode(value)
             return response
         except webob.exc.WSGIHTTPException as e:
             return translate_exception(request, e)

glance/image_cache/drivers/xattr.py

@@ -61,7 +61,6 @@ from oslo_log import log as logging
 from oslo_utils import encodeutils
 from oslo_utils import excutils
 from oslo_utils import fileutils
-import six
 import xattr
 
 from glance.common import exception
@@ -477,9 +476,7 @@ def set_xattr(path, key, value):
     """
     namespaced_key = _make_namespaced_xattr_key(key)
     if not isinstance(value, bytes):
-        value = str(value)
+        value = str(value).encode('utf-8')
-        if six.PY3:
-            value = value.encode('utf-8')
     xattr.setxattr(path, namespaced_key, value)
 
 

glance/tests/unit/common/test_wsgi.py

@@ -28,7 +28,6 @@ import fixtures
 from oslo_concurrency import processutils
 from oslo_serialization import jsonutils
 import routes
-import six
 import webob
 
 from glance.api.v2 import router as router_v2
@@ -111,12 +110,6 @@ class RequestTest(test_utils.BaseTestCase):
         self.assertEqual("application/json", result)
 
     def test_params(self):
-        if six.PY2:
-            expected = webob.multidict.NestedMultiDict({
-                'limit': '20', 'name':
-                    '\xd0\x9f\xd1\x80\xd0\xb8\xd0\xb2\xd0\xb5\xd1\x82',
-                'sort_key': 'name', 'sort_dir': 'asc'})
-        else:
         expected = webob.multidict.NestedMultiDict({
             'limit': '20', 'name': 'Привет', 'sort_key': 'name',
             'sort_dir': 'asc'})
@@ -414,8 +407,7 @@ class ResourceTest(test_utils.BaseTestCase):
         response = resource.__call__(request)
 
         # ensure it has been encoded correctly
-        value = (response.headers['unicode_test'].decode('utf-8')
+        value = response.headers['unicode_test']
-                 if six.PY2 else response.headers['unicode_test'])
         self.assertEqual(for_openstack_comrades, value)
 
 

glance/tests/unit/test_misc.py

@@ -15,8 +15,6 @@
 
 import os
 
-import six
-
 from glance.common import crypt
 from glance.common import utils
 from glance.tests import utils as test_utils
@@ -33,9 +31,7 @@ class UtilsTestCase(test_utils.BaseTestCase):
         plaintext_list = ['']
         blocksize = 64
         for i in range(3 * blocksize):
-            text = os.urandom(i)
+            text = os.urandom(i).decode('latin1')
-            if six.PY3:
-                text = text.decode('latin1')
             plaintext_list.append(text)
 
         for key in key_list:

requirements.txt

@@ -33,8 +33,6 @@ Paste>=2.0.2 # MIT
 jsonschema>=3.2.0 # MIT
 python-keystoneclient>=3.8.0 # Apache-2.0
 pyOpenSSL>=17.1.0 # Apache-2.0
-# Required by openstack.common libraries
-six>=1.11.0 # MIT
 
 oslo.db>=5.0.0 # Apache-2.0
 oslo.i18n>=5.0.0 # Apache-2.0