Remove six and python 2.7 full support

Six is in use to help us to keep support for python 2.7.
Since the ussuri cycle we decide to remove the python 2.7
support so we can go ahead and also remove six usage from
the python code.

Review process and help
-----------------------
Removing six introduce a lot of changes and an huge amount of modified files
To simplify reviews we decided to split changes into several patches to avoid
painful reviews and avoid mistakes.

To review this patch you can use the six documentation [1] to obtain help and
understand choices.

Additional informations
-----------------------
Changes related to 'six.b(data)' [2]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

six.b [2] encode the given datas in latin-1 in python3 so I did the same
things in this patch.

Latin-1 is equal to iso-8859-1 [3].

This encoding is the default encoding [4] of certain descriptive HTTP
headers.

I suggest to keep latin-1 for the moment and to move to another encoding
in a follow-up patch if needed to move to most powerful encoding (utf8).

HTML4 support utf8 charset and utf8 is the default charset for HTML5 [5].

Note that this commit message is autogenerated and not necesserly contains
changes related to 'six.b'

[1] https://six.readthedocs.io/
[2] https://six.readthedocs.io/#six.b
[3] https://docs.python.org/3/library/codecs.html#standard-encodings
[4] https://www.w3schools.com/charsets/ref_html_8859.asp
[5] https://www.w3schools.com/html/html_charset.asp

Patch 2 of a serie of 28 patches

Change-Id: I2795dee87f0e27b64820686acfc614ac2ba19a4f

10 files changed, 32 insertions, 39 deletions

diff --git a/heat/api/openstack/v1/stacks.py b/heat/api/openstack/v1/stacks.py
index d144ea197..8830c22b3 100644
--- a/heat/api/openstack/v1/stacks.py
+++ b/heat/api/openstack/v1/stacks.py
@@ -15,8 +15,7 @@
 
 import contextlib
 from oslo_log import log as logging
-import six
-from six.moves.urllib import parse
+from urllib import parse
 from webob import exc
 
 from heat.api.openstack.v1 import util
@@ -79,7 +78,7 @@ class InstantiationData(object):
         try:
             yield
         except ValueError as parse_ex:
-            mdict = {'type': data_type, 'error': six.text_type(parse_ex)}
+            mdict = {'type': data_type, 'error': str(parse_ex)}
             msg = _("%(type)s not in valid format: %(error)s") % mdict
             raise exc.HTTPBadRequest(msg)
 
@@ -101,7 +100,7 @@ class InstantiationData(object):
             try:
                 adopt_data = template_format.simple_parse(adopt_data)
                 template_format.validate_template_limit(
-                    six.text_type(adopt_data['template']))
+                    str(adopt_data['template']))
                 return adopt_data['template']
             except (ValueError, KeyError) as ex:
                 err_reason = _('Invalid adopt data: %s') % ex
@@ -109,7 +108,7 @@ class InstantiationData(object):
         elif self.PARAM_TEMPLATE in self.data:
             template_data = self.data[self.PARAM_TEMPLATE]
             if isinstance(template_data, dict):
-                template_format.validate_template_limit(six.text_type(
+                template_format.validate_template_limit(str(
                     template_data))
                 return template_data
 
@@ -188,7 +187,7 @@ class StackController(object):
         try:
             return param_utils.extract_bool(name, value)
         except ValueError as e:
-            raise exc.HTTPBadRequest(six.text_type(e))
+            raise exc.HTTPBadRequest(str(e))
 
     def _extract_int_param(self, name, value,
                            allow_zero=True, allow_negative=False):
@@ -196,13 +195,13 @@ class StackController(object):
             return param_utils.extract_int(name, value,
                                            allow_zero, allow_negative)
         except ValueError as e:
-            raise exc.HTTPBadRequest(six.text_type(e))
+            raise exc.HTTPBadRequest(str(e))
 
     def _extract_tags_param(self, tags):
         try:
             return param_utils.extract_tags(tags)
         except ValueError as e:
-            raise exc.HTTPBadRequest(six.text_type(e))
+            raise exc.HTTPBadRequest(str(e))
 
     def _index(self, req, use_admin_cnxt=False):
         filter_whitelist = {
@@ -392,7 +391,7 @@ class StackController(object):
         if not is_update and key in args:
             msg = _("%s flag only supported in stack update (or update "
                     "preview) request.") % key
-            raise exc.HTTPBadRequest(six.text_type(msg))
+            raise exc.HTTPBadRequest(str(msg))
         return args
 
     @util.registered_policy_enforce
@@ -700,7 +699,7 @@ class StackController(object):
                     req.params.get(rpc_api.TEMPLATE_TYPE))
             except ValueError as ex:
                 msg = _("Template type is not supported: %s") % ex
-                raise exc.HTTPBadRequest(six.text_type(msg))
+                raise exc.HTTPBadRequest(str(msg))
 
         return self.rpc_client.generate_template(req.context,
                                                  type_name,
@@ -753,10 +752,7 @@ class StackSerializer(serializers.JSONResponseSerializer):
 
     def _populate_response_header(self, response, location, status):
         response.status = status
-        if six.PY2:
-            response.headers['Location'] = location.encode('utf-8')
-        else:
-            response.headers['Location'] = location
+        response.headers['Location'] = location
         response.headers['Content-Type'] = 'application/json'
         return response
 
@@ -764,7 +760,7 @@ class StackSerializer(serializers.JSONResponseSerializer):
         self._populate_response_header(response,
                                        result['stack']['links'][0]['href'],
                                        201)
-        response.body = six.b(self.to_json(result))
+        response.body = self.to_json(result).encode('latin-1')
         return response
 
 
diff --git a/heat/api/openstack/v1/util.py b/heat/api/openstack/v1/util.py
index 3bf6dab13..a9f8b5cf7 100644
--- a/heat/api/openstack/v1/util.py
+++ b/heat/api/openstack/v1/util.py
@@ -11,7 +11,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-import six
+import functools
+
 from webob import exc
 
 from heat.common.i18n import _
@@ -41,7 +42,7 @@ def registered_policy_enforce(handler):
 
 
 def _policy_enforce(handler, is_registered_policy=False):
-    @six.wraps(handler)
+    @functools.wraps(handler)
     def handle_stack_method(controller, req, tenant_id, **kwargs):
         if req.context.tenant_id != tenant_id and not req.context.is_admin:
             raise exc.HTTPForbidden()
@@ -77,7 +78,7 @@ def registered_identified_stack(handler):
 
 def _identified_stack(handler, is_registered_policy=False):
 
-    @six.wraps(handler)
+    @functools.wraps(handler)
     def handle_stack_method(controller, req, stack_name, stack_id, **kwargs):
         stack_identity = identifier.HeatIdentifier(req.context.tenant_id,
                                                    stack_name,
@@ -126,7 +127,7 @@ def get_allowed_params(params, whitelist):
     """
     allowed_params = {}
 
-    for key, get_type in six.iteritems(whitelist):
+    for key, get_type in whitelist.items():
         assert get_type in PARAM_TYPES
 
         value = None
diff --git a/heat/api/openstack/v1/views/views_common.py b/heat/api/openstack/v1/views/views_common.py
index 030980066..c5514e4ba 100644
--- a/heat/api/openstack/v1/views/views_common.py
+++ b/heat/api/openstack/v1/views/views_common.py
@@ -11,7 +11,7 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from six.moves.urllib import parse as urlparse
+from urllib import parse as urlparse
 
 
 def get_collection_links(request, items):
diff --git a/heat/api/versions.py b/heat/api/versions.py
index 41cbf2699..c49b0ec76 100644
--- a/heat/api/versions.py
+++ b/heat/api/versions.py
@@ -13,9 +13,9 @@
 
 """Controller that returns information on the heat API versions."""
 
+import http.client
+
 from oslo_serialization import jsonutils
-import six
-from six.moves import http_client
 import webob.dec
 
 
@@ -43,11 +43,11 @@ class Controller(object):
         body = jsonutils.dumps(dict(versions=version_objs))
 
         response = webob.Response(request=req,
-                                  status=http_client.MULTIPLE_CHOICES,
+                                  status=http.client.MULTIPLE_CHOICES,
                                   content_type='application/json')
         # NOTE(pas-ha) in WebOb, Response.body accepts only bytes,
         # and Response.text accepts only unicode.
-        response.text = six.text_type(body)
+        response.text = str(body)
 
         return response
 
diff --git a/heat/cmd/all.py b/heat/cmd/all.py
index 51e0bb039..526bc7fa2 100644
--- a/heat/cmd/all.py
+++ b/heat/cmd/all.py
@@ -27,7 +27,6 @@ from oslo_config import cfg
 import oslo_i18n as i18n
 from oslo_log import log as logging
 from oslo_service import systemd
-import six
 
 from heat.cmd import api
 from heat.cmd import api_cfn
@@ -86,5 +85,5 @@ def main():
         systemd.notify_once()
         [service.wait() for service in services]
     except RuntimeError as e:
-        msg = six.text_type(e)
+        msg = str(e)
         sys.exit("ERROR: %s" % msg)
diff --git a/heat/cmd/api.py b/heat/cmd/api.py
index 9d968c047..b8ea0111c 100644
--- a/heat/cmd/api.py
+++ b/heat/cmd/api.py
@@ -28,7 +28,6 @@ import oslo_i18n as i18n
 from oslo_log import log as logging
 from oslo_reports import guru_meditation_report as gmr
 from oslo_service import systemd
-import six
 
 from heat.common import config
 from heat.common import messaging
@@ -72,5 +71,5 @@ def main():
         systemd.notify_once()
         server.wait()
     except RuntimeError as e:
-        msg = six.text_type(e)
+        msg = str(e)
         sys.exit("ERROR: %s" % msg)
diff --git a/heat/cmd/api_cfn.py b/heat/cmd/api_cfn.py
index b632c0f14..bc7cd5b02 100644
--- a/heat/cmd/api_cfn.py
+++ b/heat/cmd/api_cfn.py
@@ -30,7 +30,6 @@ import oslo_i18n as i18n
 from oslo_log import log as logging
 from oslo_reports import guru_meditation_report as gmr
 from oslo_service import systemd
-import six
 
 from heat.common import config
 from heat.common import messaging
@@ -76,5 +75,5 @@ def main():
         systemd.notify_once()
         server.wait()
     except RuntimeError as e:
-        msg = six.text_type(e)
+        msg = str(e)
         sys.exit("ERROR: %s" % msg)
diff --git a/heat/cmd/manage.py b/heat/cmd/manage.py
index 6856f12d3..9f3a9b04b 100644
--- a/heat/cmd/manage.py
+++ b/heat/cmd/manage.py
@@ -19,7 +19,6 @@ import sys
 
 from oslo_config import cfg
 from oslo_log import log
-from six import moves
 
 from heat.common import context
 from heat.common import exception
@@ -106,7 +105,7 @@ def do_reset_stack_status():
             "intended to recover from specific crashes."))
     print(_("It is advised to shutdown all Heat engines beforehand."))
     print(_("Continue ? [y/N]"))
-    data = moves.input()
+    data = input()
     if not data.lower().startswith('y'):
         return
     ctxt = context.get_admin_context()
diff --git a/heat/common/context.py b/heat/common/context.py
index 0911982c3..7a1827cda 100644
--- a/heat/common/context.py
+++ b/heat/common/context.py
@@ -11,6 +11,8 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
+import functools
+
 from keystoneauth1 import access
 from keystoneauth1.identity import access as access_plugin
 from keystoneauth1.identity import generic
@@ -23,7 +25,6 @@ from oslo_log import log as logging
 import oslo_messaging
 from oslo_middleware import request_id as oslo_request_id
 from oslo_utils import importutils
-import six
 
 from heat.common import config
 from heat.common import endpoint_utils
@@ -407,7 +408,7 @@ def ContextMiddleware_filter_factory(global_conf, **local_conf):
 
 
 def request_context(func):
-    @six.wraps(func)
+    @functools.wraps(func)
     def wrapped(self, ctx, *args, **kwargs):
         try:
             return func(self, ctx, *args, **kwargs)
diff --git a/heat/common/environment_util.py b/heat/common/environment_util.py
index f060ca019..abf081bd0 100644
--- a/heat/common/environment_util.py
+++ b/heat/common/environment_util.py
@@ -13,7 +13,6 @@
 import collections
 
 from oslo_serialization import jsonutils
-import six
 
 from heat.common import environment_format as env_fmt
 from heat.common import exception
@@ -62,10 +61,10 @@ def merge_map(old, new, deep_merge=False):
                 old_v = old.get(k)
                 old[k] = merge_map(old_v, v, deep_merge) if old_v else v
             elif (isinstance(v, collections.Sequence) and
-                    not isinstance(v, six.string_types)):
+                    not isinstance(v, str)):
                 old_v = old.get(k)
                 old[k] = merge_list(old_v, v) if old_v else v
-            elif isinstance(v, six.string_types):
+            elif isinstance(v, str):
                 old[k] = ''.join([old.get(k, ''), v])
             else:
                 old[k] = v
@@ -76,14 +75,14 @@ def merge_map(old, new, deep_merge=False):
 def parse_param(p_val, p_schema):
     try:
         if p_schema.type == p_schema.MAP:
-            if not isinstance(p_val, six.string_types):
+            if not isinstance(p_val, str):
                 p_val = jsonutils.dumps(p_val)
             if p_val:
                 return jsonutils.loads(p_val)
         elif not isinstance(p_val, collections.Sequence):
             raise ValueError()
     except (ValueError, TypeError) as err:
-        msg = _("Invalid parameter in environment %s.") % six.text_type(err)
+        msg = _("Invalid parameter in environment %s.") % str(err)
         raise ValueError(msg)
     return p_val