Merge "Update charm to use Python 3"

.gitignore

@@ -9,3 +9,4 @@ tags
 trusty/
 xenial/
 .stestr
+__pycache__

actions/actions.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python3
 #
 # Copyright 2016 Canonical Ltd
 #

actions/git_reinstall.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python3
 #
 # Copyright 2016 Canonical Ltd
 #

actions/openstack_upgrade.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python3
 #
 # Copyright 2016 Canonical Ltd
 #

hooks/install

@@ -1,20 +0,0 @@
-#!/bin/bash
-# Wrapper to deal with newer Ubuntu versions that don't have py2 installed
-# by default.
-
-declare -a DEPS=('apt' 'netaddr' 'netifaces' 'pip' 'yaml')
-
-check_and_install() {
-    pkg="${1}-${2}"
-    if ! dpkg -s ${pkg} 2>&1 > /dev/null; then
-        apt-get -y install ${pkg}
-    fi
-}
-
-PYTHON="python"
-
-for dep in ${DEPS[@]}; do
-    check_and_install ${PYTHON} ${dep}
-done
-
-exec ./hooks/install.real

hooks/install

@@ -0,0 +1 @@
+neutron_api_hooks.py

hooks/install.real

@@ -1 +0,0 @@
-neutron_api_hooks.py

hooks/neutron_api_context.py

@@ -349,7 +349,7 @@ class NeutronCCContext(context.NeutronContext):
         cmp_release = CompareOpenStackReleases(release)
         if config('neutron-plugin') in ['vsp']:
             _config = config()
-            for k, v in _config.iteritems():
+            for k, v in _config.items():
                 if k.startswith('vsd'):
                     ctxt[k.replace('-', '_')] = v
             for rid in relation_ids('vsd-rest-api'):

hooks/neutron_api_hooks.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python3
 #
 # Copyright 2016 Canonical Ltd
 #
@@ -186,8 +186,7 @@ def configure_https():
         identity_joined(rid=rid)
 
 
-@hooks.hook('install.real')
+@hooks.hook('install')
-@hooks.hook()
 @harden()
 def install():
     status_set('maintenance', 'Executing pre-install')

hooks/neutron_api_utils.py

@@ -20,6 +20,7 @@ import shutil
 import subprocess
 import uuid
 import glob
+import yaml
 from base64 import b64encode
 from charmhelpers.contrib.openstack import context, templating
 from charmhelpers.contrib.openstack.neutron import (
@@ -512,14 +513,14 @@ def register_configs(release=None):
     release = release or os_release('neutron-common')
     configs = templating.OSConfigRenderer(templates_dir=TEMPLATES,
                                           openstack_release=release)
-    for cfg, rscs in resource_map().iteritems():
+    for cfg, rscs in resource_map().items():
         configs.register(cfg, rscs['contexts'])
     return configs
 
 
 def restart_map():
     return OrderedDict([(cfg, v['services'])
-                        for cfg, v in resource_map().iteritems()
+                        for cfg, v in resource_map().items()
                         if v['services']])
 
 
@@ -688,22 +689,43 @@ def setup_ipv6():
         apt_install('haproxy/trusty-backports', fatal=True)
 
 
+class FakeNeutronClient(object):
+    '''Fake wrapper for Neutron Client'''
+
+    def __init__(self, username, password, tenant_name,
+                 auth_url, region_name):
+        self.env = {
+            'OS_USERNAME': username,
+            'OS_PASSWORD': password,
+            'OS_TENANT_NAME': tenant_name,
+            'OS_AUTH_URL': auth_url,
+            'OS_REGION': region_name,
+        }
+
+    def list_routers(self):
+        cmd = ['neutron', 'router-list', '-f', 'yaml']
+        try:
+            routers = subprocess.check_output(
+                cmd, env=self.env).decode('UTF-8')
+            return {'routers': yaml.load(routers)}
+        except subprocess.CalledProcessError:
+            return {'routers': []}
+
+
 def get_neutron_client():
     ''' Return a neutron client if possible '''
     env = neutron_api_context.IdentityServiceContext()()
     if not env:
         log('Unable to check resources at this time')
-        return
+        return None
 
-    auth_url = '%(auth_protocol)s://%(auth_host)s:%(auth_port)s/v2.0' % env
+    auth_url = '{auth_protocol}://{auth_host}:{auth_port}/v2.0'.format(**env)
-    # Late import to avoid install hook failures when pkg hasnt been installed
+
-    from neutronclient.v2_0 import client
+    return FakeNeutronClient(username=env['admin_user'],
-    neutron_client = client.Client(username=env['admin_user'],
                              password=env['admin_password'],
                              tenant_name=env['admin_tenant_name'],
                              auth_url=auth_url,
                              region_name=env['region'])
-    return neutron_client
 
 
 def router_feature_present(feature):
@@ -760,10 +782,10 @@ def git_pre_install():
     add_user_to_group('neutron', 'neutron')
 
     for d in dirs:
-        mkdir(d, owner='neutron', group='neutron', perms=0755, force=False)
+        mkdir(d, owner='neutron', group='neutron', perms=0o755, force=False)
 
     for l in logs:
-        write_file(l, '', owner='neutron', group='neutron', perms=0600)
+        write_file(l, '', owner='neutron', group='neutron', perms=0o600)
 
 
 def git_post_install(projects_yaml):

test-requirements.txt

@@ -5,12 +5,12 @@ coverage>=3.6
 mock>=1.2
 flake8>=2.2.4,<=2.4.1
 os-testr>=0.4.1
-charm-tools>=2.0.0
+charm-tools>=2.0.0;python_version=='2.7'
 requests==2.6.0
 # BEGIN: Amulet OpenStack Charm Helper Requirements
 # Liberty client lower constraints
-amulet>=1.14.3,<2.0
+amulet>=1.14.3,<2.0;python_version=='2.7'
-bundletester>=0.6.1,<1.0
+bundletester>=0.6.1,<1.0;python_version=='2.7'
 python-ceilometerclient>=1.5.0
 python-cinderclient>=1.4.0
 python-glanceclient>=1.1.0

tox.ini

@@ -2,7 +2,7 @@
 # This file is managed centrally by release-tools and should not be modified
 # within individual charm repos.
 [tox]
-envlist = pep8,py27
+envlist = pep8,py27,py35
 skipsdist = True
 
 [testenv]
@@ -20,6 +20,7 @@ passenv = HOME TERM AMULET_* CS_API_*
 basepython = python2.7
 deps = -r{toxinidir}/requirements.txt
        -r{toxinidir}/test-requirements.txt
+commands = /bin/true
 
 [testenv:py35]
 basepython = python3.5

unit_tests/__init__.py

@@ -16,3 +16,4 @@ import sys
 
 sys.path.append('actions/')
 sys.path.append('hooks/')
+sys.path.append('unit_tests')

unit_tests/test_neutron_api_context.py

@@ -63,10 +63,8 @@ class GeneralTests(CharmTestCase):
 
     def test_get_tenant_network_types_unsupported(self):
         self.test_config.set('overlay-network-type', 'tokenring')
-        with self.assertRaises(ValueError) as _exceptctxt:
+        with self.assertRaises(ValueError):
             context._get_tenant_network_types()
-        self.assertEqual(_exceptctxt.exception.message,
-                         'Unsupported overlay-network-type tokenring')
 
     def test_get_tenant_network_types_default(self):
         self.test_config.set('overlay-network-type', 'gre vxlan')
@@ -92,20 +90,14 @@ class GeneralTests(CharmTestCase):
     def test_get_tenant_network_types_unsupported_default(self):
         self.test_config.set('overlay-network-type', '')
         self.test_config.set('default-tenant-network-type', 'whizzy')
-        with self.assertRaises(ValueError) as _exceptctxt:
+        with self.assertRaises(ValueError):
             context._get_tenant_network_types()
-        self.assertEqual(_exceptctxt.exception.message,
-                         'Unsupported or unconfigured '
-                         'default-tenant-network-type whizzy')
 
     def test_get_tenant_network_types_unconfigured_default(self):
         self.test_config.set('overlay-network-type', 'gre')
         self.test_config.set('default-tenant-network-type', 'vxlan')
-        with self.assertRaises(ValueError) as _exceptctxt:
+        with self.assertRaises(ValueError):
             context._get_tenant_network_types()
-        self.assertEqual(_exceptctxt.exception.message,
-                         'Unsupported or unconfigured '
-                         'default-tenant-network-type vxlan')
 
     def test_get_l3ha(self):
         self.test_config.set('enable-l3ha', True)
@@ -317,7 +309,7 @@ class HAProxyContextTest(CharmTestCase):
     def test_context_No_peers(self, _log, _rids, _mkdir):
         _rids.return_value = []
         hap_ctxt = context.HAProxyContext()
-        with patch('__builtin__.__import__'):
+        with patch('builtins.__import__'):
             self.assertTrue('units' not in hap_ctxt())
 
     @patch.object(charmhelpers.contrib.openstack.context, 'mkdir')
@@ -333,8 +325,8 @@ class HAProxyContextTest(CharmTestCase):
     @patch.object(charmhelpers.contrib.openstack.context, 'relation_ids')
     @patch.object(charmhelpers.contrib.openstack.context, 'log')
     @patch.object(charmhelpers.contrib.openstack.context, 'kv')
-    @patch('__builtin__.__import__')
+    @patch('builtins.__import__')
-    @patch('__builtin__.open')
+    @patch('builtins.open')
     def test_context_peers(self, _open, _import, _kv, _log, _rids, _runits,
                            _rget, _uget, _lunit, _config,
                            _get_address_in_network, _get_netmask_for_address,
@@ -414,7 +406,7 @@ class NeutronCCContextTest(CharmTestCase):
 
     @patch.object(context.NeutronCCContext, 'network_manager')
     @patch.object(context.NeutronCCContext, 'plugin')
-    @patch('__builtin__.__import__')
+    @patch('builtins.__import__')
     def test_neutroncc_context_no_setting(self, _import, plugin, nm):
         plugin.return_value = None
         ctxt_data = {
@@ -502,7 +494,7 @@ class NeutronCCContextTest(CharmTestCase):
 
     @patch.object(context.NeutronCCContext, 'network_manager')
     @patch.object(context.NeutronCCContext, 'plugin')
-    @patch('__builtin__.__import__')
+    @patch('builtins.__import__')
     def test_neutroncc_context_vxlan(self, _import, plugin, nm):
         plugin.return_value = None
         self.test_config.set('flat-network-providers', 'physnet2 physnet3')
@@ -550,7 +542,7 @@ class NeutronCCContextTest(CharmTestCase):
 
     @patch.object(context.NeutronCCContext, 'network_manager')
     @patch.object(context.NeutronCCContext, 'plugin')
-    @patch('__builtin__.__import__')
+    @patch('builtins.__import__')
     def test_neutroncc_context_l3ha(self, _import, plugin, nm):
         plugin.return_value = None
         self.test_config.set('enable-l3ha', True)
@@ -602,7 +594,7 @@ class NeutronCCContextTest(CharmTestCase):
 
     @patch.object(context.NeutronCCContext, 'network_manager')
     @patch.object(context.NeutronCCContext, 'plugin')
-    @patch('__builtin__.__import__')
+    @patch('builtins.__import__')
     def test_neutroncc_context_l3ha_l3_agents(self, _import, plugin, nm):
         plugin.return_value = None
         self.os_release.return_value = 'juno'
@@ -616,7 +608,7 @@ class NeutronCCContextTest(CharmTestCase):
 
     @patch.object(context.NeutronCCContext, 'network_manager')
     @patch.object(context.NeutronCCContext, 'plugin')
-    @patch('__builtin__.__import__')
+    @patch('builtins.__import__')
     def test_neutroncc_context_sriov(self, _import, plugin, nm):
         plugin.return_value = None
         self.test_config.set('enable-sriov', True)
@@ -660,7 +652,7 @@ class NeutronCCContextTest(CharmTestCase):
 
     @patch.object(context.NeutronCCContext, 'network_manager')
     @patch.object(context.NeutronCCContext, 'plugin')
-    @patch('__builtin__.__import__')
+    @patch('builtins.__import__')
     def test_neutroncc_context_unsupported_overlay(self, _import, plugin, nm):
         plugin.return_value = None
         self.test_config.set('overlay-network-type', 'bobswitch')
@@ -669,7 +661,7 @@ class NeutronCCContextTest(CharmTestCase):
 
     @patch.object(context.NeutronCCContext, 'network_manager')
     @patch.object(context.NeutronCCContext, 'plugin')
-    @patch('__builtin__.__import__')
+    @patch('builtins.__import__')
     def test_neutroncc_context_api_rel(self, _import, plugin, nm):
         nova_url = 'http://127.0.0.10'
         plugin.return_value = None
@@ -697,7 +689,7 @@ class NeutronCCContextTest(CharmTestCase):
 
     @patch.object(context.NeutronCCContext, 'network_manager')
     @patch.object(context.NeutronCCContext, 'plugin')
-    @patch('__builtin__.__import__')
+    @patch('builtins.__import__')
     def test_neutroncc_context_nsx(self, _import, plugin, nm):
         plugin.return_value = 'nsx'
         self.os_release.return_value = 'havana'
@@ -712,12 +704,12 @@ class NeutronCCContextTest(CharmTestCase):
             'nsx_tz_uuid': 'tzuuid',
             'nsx_username': 'bob',
         }
-        for key in expect.iterkeys():
+        for key in expect.keys():
             self.assertEqual(napi_ctxt[key], expect[key])
 
     @patch.object(context.NeutronCCContext, 'network_manager')
     @patch.object(context.NeutronCCContext, 'plugin')
-    @patch('__builtin__.__import__')
+    @patch('builtins.__import__')
     def test_neutroncc_context_nuage(self, _import, plugin, nm):
         plugin.return_value = 'vsp'
         self.os_release.return_value = 'havana'
@@ -732,12 +724,12 @@ class NeutronCCContextTest(CharmTestCase):
             'vsd_base_uri': '/nuage/api/v1_0',
             'vsd_netpart_name': 'foo-enterprise',
         }
-        for key in expect.iterkeys():
+        for key in expect.keys():
             self.assertEqual(napi_ctxt[key], expect[key])
 
     @patch.object(context.NeutronCCContext, 'network_manager')
     @patch.object(context.NeutronCCContext, 'plugin')
-    @patch('__builtin__.__import__')
+    @patch('builtins.__import__')
     def test_neutroncc_context_qos(self, _import, plugin, nm):
         plugin.return_value = None
         self.os_release.return_value = 'mitaka'
@@ -749,12 +741,12 @@ class NeutronCCContextTest(CharmTestCase):
             'extension_drivers': 'qos',
             'service_plugins': service_plugins,
         }
-        for key in expect.iterkeys():
+        for key in expect.keys():
             self.assertEqual(napi_ctxt[key], expect[key])
 
     @patch.object(context.NeutronCCContext, 'network_manager')
     @patch.object(context.NeutronCCContext, 'plugin')
-    @patch('__builtin__.__import__')
+    @patch('builtins.__import__')
     def test_neutroncc_context_service_plugins(self, _import, plugin, nm):
         plugin.return_value = None
         self.test_config.set('enable-qos', False)

unit_tests/test_neutron_api_hooks.py

@@ -151,7 +151,7 @@ class NeutronAPIHooksTests(CharmTestCase):
         _port_calls = [call(port) for port in _ports]
         self.determine_packages.return_value = _pkgs
         self.determine_ports.return_value = _ports
-        self._call_hook('install.real')
+        self._call_hook('install')
         self.configure_installation_source.assert_called_with(
             'distro'
         )
@@ -174,7 +174,7 @@ class NeutronAPIHooksTests(CharmTestCase):
         _port_calls = [call(port) for port in _ports]
         self.determine_packages.return_value = _pkgs
         self.determine_ports.return_value = _ports
-        self._call_hook('install.real')
+        self._call_hook('install')
         self.configure_installation_source.assert_called_with(
             'distro'
         )
@@ -210,7 +210,7 @@ class NeutronAPIHooksTests(CharmTestCase):
         self.test_config.set('openstack-origin', repo)
         self.test_config.set('openstack-origin-git', projects_yaml)
         codename.return_value = 'juno'
-        self._call_hook('install.real')
+        self._call_hook('install')
         self.assertTrue(self.execd_preinstall.called)
         self.configure_installation_source.assert_called_with(repo)
         self.apt_update.assert_called_with(fatal=True)
@@ -251,22 +251,16 @@ class NeutronAPIHooksTests(CharmTestCase):
         self.neutron_ready.return_value = True
         self.dvr_router_present.return_value = True
         self.get_dvr.return_value = False
-        with self.assertRaises(Exception) as context:
+        with self.assertRaises(Exception):
             self._call_hook('config-changed')
-        self.assertEqual(context.exception.message,
-                         'Cannot disable dvr while dvr enabled routers exist.'
-                         ' Please remove any distributed routers')
 
     def test_config_changed_nol3ha_harouters(self):
         self.neutron_ready.return_value = True
         self.dvr_router_present.return_value = False
         self.l3ha_router_present.return_value = True
         self.get_l3ha.return_value = False
-        with self.assertRaises(Exception) as context:
+        with self.assertRaises(Exception):
             self._call_hook('config-changed')
-        self.assertEqual(context.exception.message,
-                         'Cannot disable Router HA while ha enabled routers'
-                         ' exist. Please remove any ha routers')
 
     @patch.object(utils, 'get_os_codename_install_source')
     @patch.object(hooks, 'configure_https')
@@ -372,12 +366,8 @@ class NeutronAPIHooksTests(CharmTestCase):
 
     def test_db_joined_with_postgresql(self):
         self.is_relation_made.return_value = True
-
+        with self.assertRaises(Exception):
-        with self.assertRaises(Exception) as context:
             hooks.db_joined()
-        self.assertEqual(context.exception.message,
-                         'Attempting to associate a mysql database when there '
-                         'is already associated a postgresql one')
 
     def test_postgresql_db_joined(self):
         self.unit_get.return_value = 'myhostname'
@@ -389,12 +379,8 @@ class NeutronAPIHooksTests(CharmTestCase):
 
     def test_postgresql_joined_with_db(self):
         self.is_relation_made.return_value = True
-
+        with self.assertRaises(Exception):
-        with self.assertRaises(Exception) as context:
             hooks.pgsql_neutron_db_joined()
-        self.assertEqual(context.exception.message,
-                         'Attempting to associate a postgresql database when'
-                         ' there is already associated a mysql one')
 
     @patch.object(hooks, 'neutron_plugin_api_subordinate_relation_joined')
     @patch.object(hooks, 'conditional_neutron_migration')

unit_tests/test_neutron_api_utils.py

@@ -127,7 +127,7 @@ class TestNeutronAPIUtils(CharmTestCase):
         pkg_list = nutils.determine_packages()
         expect = deepcopy(nutils.BASE_PACKAGES)
         expect.extend(['neutron-server', 'neutron-plugin-ml2'])
-        self.assertItemsEqual(pkg_list, expect)
+        self.assertEqual(sorted(pkg_list), sorted(expect))
 
     @patch.object(nutils, 'git_install_requested')
     def test_determine_vsp_packages(self, git_requested):
@@ -141,7 +141,7 @@ class TestNeutronAPIUtils(CharmTestCase):
         expect = deepcopy(nutils.BASE_PACKAGES)
         expect.extend(['neutron-server', 'neutron-plugin-nuage',
                        'python-nuagenetlib', 'nuage-neutron'])
-        self.assertItemsEqual(pkg_list, expect)
+        self.assertEqual(sorted(pkg_list), sorted(expect))
 
     @patch.object(nutils, 'git_install_requested')
     def test_determine_packages_kilo(self, git_requested):
@@ -153,7 +153,7 @@ class TestNeutronAPIUtils(CharmTestCase):
         expect.extend(['neutron-server', 'neutron-plugin-ml2',
                       'python-networking-hyperv'])
         expect.extend(nutils.KILO_PACKAGES)
-        self.assertItemsEqual(pkg_list, expect)
+        self.assertEqual(sorted(pkg_list), sorted(expect))
 
     @patch.object(nutils, 'git_install_requested')
     def test_determine_packages_noplugin(self, git_requested):
@@ -164,12 +164,12 @@ class TestNeutronAPIUtils(CharmTestCase):
         pkg_list = nutils.determine_packages()
         expect = deepcopy(nutils.BASE_PACKAGES)
         expect.extend(['neutron-server'])
-        self.assertItemsEqual(pkg_list, expect)
+        self.assertEqual(sorted(pkg_list), sorted(expect))
 
     def test_determine_ports(self):
         self.os_release.return_value = 'havana'
         port_list = nutils.determine_ports()
-        self.assertItemsEqual(port_list, [9696])
+        self.assertEqual(port_list, [9696])
 
     @patch.object(nutils, 'manage_plugin')
     @patch('os.path.exists')
@@ -232,26 +232,14 @@ class TestNeutronAPIUtils(CharmTestCase):
         _restart_map = nutils.restart_map()
         ML2CONF = "/etc/neutron/plugins/ml2/ml2_conf.ini"
         expect = OrderedDict([
-            (nutils.NEUTRON_CONF, {
+            (nutils.NEUTRON_CONF, ['neutron-server']),
-                'services': ['neutron-server'],
+            (nutils.NEUTRON_DEFAULT, ['neutron-server']),
-            }),
+            (nutils.API_PASTE_INI, ['neutron-server']),
-            (nutils.NEUTRON_DEFAULT, {
+            (nutils.APACHE_CONF, ['apache2']),
-                'services': ['neutron-server'],
+            (nutils.HAPROXY_CONF, ['haproxy']),
-            }),
+            (ML2CONF, ['neutron-server']),
-            (nutils.API_PASTE_INI, {
-                'services': ['neutron-server'],
-            }),
-            (ML2CONF, {
-                'services': ['neutron-server'],
-            }),
-            (nutils.APACHE_CONF, {
-                'services': ['apache2'],
-            }),
-            (nutils.HAPROXY_CONF, {
-                'services': ['haproxy'],
-            }),
         ])
-        self.assertItemsEqual(_restart_map, expect)
+        self.assertEqual(_restart_map, expect)
 
     @patch('os.path.exists')
     def test_register_configs(self, mock_path_exists):
@@ -275,7 +263,7 @@ class TestNeutronAPIUtils(CharmTestCase):
                  '/etc/neutron/plugins/ml2/ml2_conf.ini',
                  '/etc/apache2/sites-available/openstack_https_frontend',
                  '/etc/haproxy/haproxy.cfg']
-        self.assertItemsEqual(_regconfs.configs, confs)
+        self.assertEqual(sorted(_regconfs.configs), sorted(confs))
 
     @patch('os.path.isfile')
     def test_keystone_ca_cert_b64_no_cert_file(self, _isfile):
@@ -390,7 +378,7 @@ class TestNeutronAPIUtils(CharmTestCase):
         self.assertFalse(migrate_neutron_db.called)
 
     @patch.object(ncontext, 'IdentityServiceContext')
-    @patch('neutronclient.v2_0.client.Client')
+    @patch.object(nutils, 'FakeNeutronClient')
     def test_get_neutron_client(self, nclient, IdentityServiceContext):
         creds = {
             'auth_protocol': 'http',
@@ -533,16 +521,16 @@ class TestNeutronAPIUtils(CharmTestCase):
         add_user_to_group.assert_called_with('neutron', 'neutron')
         expected = [
             call('/var/lib/neutron', owner='neutron',
-                 group='neutron', perms=0755, force=False),
+                 group='neutron', perms=0o755, force=False),
             call('/var/lib/neutron/lock', owner='neutron',
-                 group='neutron', perms=0755, force=False),
+                 group='neutron', perms=0o755, force=False),
             call('/var/log/neutron', owner='neutron',
-                 group='neutron', perms=0755, force=False),
+                 group='neutron', perms=0o755, force=False),
         ]
         self.assertEqual(mkdir.call_args_list, expected)
         expected = [
             call('/var/log/neutron/server.log', '', owner='neutron',
-                 group='neutron', perms=0600),
+                 group='neutron', perms=0o600),
         ]
         self.assertEqual(write_file.call_args_list, expected)
 

unit_tests/test_utils.py

@@ -12,6 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+import io
 import os
 import logging
 import unittest
@@ -54,7 +55,7 @@ def get_default_config():
     '''
     default_config = {}
     config = load_config()
-    for k, v in config.iteritems():
+    for k, v in config.items():
         if 'default' in v:
             default_config[k] = v['default']
         else:
@@ -128,12 +129,12 @@ def patch_open():
 
     Yields the mock for "open" and "file", respectively.'''
     mock_open = MagicMock(spec=open)
-    mock_file = MagicMock(spec=file)
+    mock_file = MagicMock(spec=io.FileIO)
 
     @contextmanager
     def stub_open(*args, **kwargs):
         mock_open(*args, **kwargs)
         yield mock_file
 
-    with patch('__builtin__.open', stub_open):
+    with patch('builtins.open', stub_open):
         yield mock_open, mock_file