Port more guestagent unit tests to Python 3

* mysql: open temporary file in text mode, not in binary mode
* operating_system: open files in text mode, not in binary mode, and
  flush explicitly the file rather than using unbuffered file. On
  Python 3, it's no more possible to open a text file in unbuffered
  mode (it would be very inefficient).
* CouchbaseRootAccess.write_password_to_file(): encode password to
  UTF-8 if it's an unicode string.
* Replace ConfigParser import with six.moves.configparser
* Replace exc.message with exception_to_unicode(exc)
* tox: run the following guestagent unit tests on Python 3.4

  - test_backups.py
  - test_configuration.py
  - test_couchbase_manager.py
  - test_couchdb_manager.py
  - test_db2_manager.py
  - test_dbmodels.py
  - test_galera_manager.py
  - test_manager.py
  - test_mariadb_manager.py
  - test_mongodb_cluster_manager.py
  - test_mysql_manager.py
  - test_redis_manager.py
  - test_vertica_manager.py

Partially implements: blueprint trove-python3
Change-Id: I7bf477b328dfe15c5339cda1b80e44358019bfff

tox.ini

@@ -69,13 +69,26 @@ commands =
         trove/tests/unittests/dns/test_designate_driver.py \
         trove/tests/unittests/guestagent/test_agent_heartbeats_models.py \
         trove/tests/unittests/guestagent/test_api.py \
+        trove/tests/unittests/guestagent/test_backups.py \
+        trove/tests/unittests/guestagent/test_configuration.py \
+        trove/tests/unittests/guestagent/test_couchbase_manager.py \
+        trove/tests/unittests/guestagent/test_couchdb_manager.py \
+        trove/tests/unittests/guestagent/test_db2_manager.py \
+        trove/tests/unittests/guestagent/test_dbmodels.py \
         trove/tests/unittests/guestagent/test_galera_cluster_api.py \
+        trove/tests/unittests/guestagent/test_galera_manager.py \
         trove/tests/unittests/guestagent/test_guestagent_utils.py \
+        trove/tests/unittests/guestagent/test_manager.py \
+        trove/tests/unittests/guestagent/test_mariadb_manager.py \
         trove/tests/unittests/guestagent/test_models.py \
+        trove/tests/unittests/guestagent/test_mongodb_cluster_manager.py \
+        trove/tests/unittests/guestagent/test_mysql_manager.py \
         trove/tests/unittests/guestagent/test_pkg.py \
         trove/tests/unittests/guestagent/test_query.py \
+        trove/tests/unittests/guestagent/test_redis_manager.py \
         trove/tests/unittests/guestagent/test_service.py \
         trove/tests/unittests/guestagent/test_vertica_api.py \
+        trove/tests/unittests/guestagent/test_vertica_manager.py \
         trove/tests/unittests/instance/test_instance_controller.py \
         trove/tests/unittests/instance/test_instance_models.py \
         trove/tests/unittests/instance/test_instance_status.py \

trove/guestagent/common/operating_system.py

@@ -59,7 +59,7 @@ def read_file(path, codec=IdentityCodec(), as_root=False, decode=True):
         if as_root:
             return _read_file_as_root(path, codec, decode=decode)
 
-        with open(path, 'rb') as fp:
+        with open(path, 'r') as fp:
             if decode:
                 return codec.deserialize(fp.read())
             return codec.serialize(fp.read())
@@ -144,11 +144,12 @@ def write_file(path, data, codec=IdentityCodec(), as_root=False, encode=True):
         if as_root:
             _write_file_as_root(path, data, codec, encode=encode)
         else:
-            with open(path, 'wb', 0) as fp:
+            with open(path, 'w') as fp:
                 if encode:
                     fp.write(codec.serialize(data))
                 else:
                     fp.write(codec.deserialize(data))
+                fp.flush()
     else:
         raise exception.UnprocessableEntity(_("Invalid path: %s") % path)
 
@@ -170,11 +171,12 @@ def _write_file_as_root(path, data, codec, encode=True):
     """
     # The files gets removed automatically once the managing object goes
     # out of scope.
-    with tempfile.NamedTemporaryFile('wb', 0, delete=False) as fp:
+    with tempfile.NamedTemporaryFile('w', delete=False) as fp:
         if encode:
             fp.write(codec.serialize(data))
         else:
             fp.write(codec.deserialize(data))
+        fp.flush()
         fp.close()  # Release the resource before proceeding.
         copy(fp.name, path, force=True, as_root=True)
 

trove/guestagent/datastore/experimental/couchbase/service.py

@@ -22,6 +22,7 @@ import tempfile
 from oslo_log import log as logging
 from oslo_utils import netutils
 import pexpect
+import six
 
 from trove.common import cfg
 from trove.common import exception
@@ -246,6 +247,8 @@ class CouchbaseRootAccess(object):
         try:
             tempfd, tempname = tempfile.mkstemp()
             os.fchmod(tempfd, stat.S_IRUSR | stat.S_IWUSR)
+            if isinstance(root_password, six.text_type):
+                root_password = root_password.encode('utf-8')
             os.write(tempfd, root_password)
             os.fchmod(tempfd, stat.S_IRUSR)
             os.close(tempfd)

trove/guestagent/datastore/experimental/vertica/service.py

@@ -11,13 +11,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import ConfigParser
 import os
 import subprocess
 import tempfile
 
 from oslo_log import log as logging
 from oslo_utils import netutils
+from six.moves import configparser
 
 from trove.common import cfg
 from trove.common import exception
@@ -361,7 +361,7 @@ class VerticaApp(object):
 
     def _generate_database_password(self):
         """Generate and write the password to vertica.cnf file."""
-        config = ConfigParser.ConfigParser()
+        config = configparser.ConfigParser()
         config.add_section('credentials')
         config.set('credentials', 'dbadmin_password',
                    utils.generate_random_password())
@@ -388,7 +388,7 @@ class VerticaApp(object):
     def read_config(self):
         """Reads and returns the Vertica config."""
         try:
-            config = ConfigParser.ConfigParser()
+            config = configparser.ConfigParser()
             config.read(system.VERTICA_CONF)
             return config
         except Exception:

trove/guestagent/datastore/manager.py

@@ -19,6 +19,7 @@ import abc
 from oslo_config import cfg as oslo_cfg
 from oslo_log import log as logging
 from oslo_service import periodic_task
+from oslo_utils import encodeutils
 
 from trove.common import cfg
 from trove.common import exception
@@ -285,7 +286,7 @@ class Manager(periodic_task.PeriodicTasks):
         except Exception as ex:
             self.prepare_error = True
             LOG.exception(_("An error occurred preparing datastore: %s") %
-                          ex.message)
+                          encodeutils.exception_to_unicode(ex))
             raise
         finally:
             LOG.info(_("Ending datastore prepare for '%s'.") % self.manager)

trove/guestagent/strategies/restore/mysql_impl.py

@@ -132,7 +132,7 @@ class MySQLRestoreMixin(object):
         for initial datastore configuration.
         """
 
-        with tempfile.NamedTemporaryFile() as init_file:
+        with tempfile.NamedTemporaryFile(mode='w') as init_file:
             operating_system.chmod(init_file.name, FileMode.ADD_READ_ALL,
                                    as_root=True)
             self._writelines_one_per_line(init_file,

trove/tests/unittests/guestagent/test_manager.py

@@ -22,6 +22,7 @@ from mock import DEFAULT
 from mock import MagicMock
 from mock import Mock
 from mock import patch
+from oslo_utils import encodeutils
 from proboscis.asserts import assert_equal
 from proboscis.asserts import assert_true
 
@@ -462,8 +463,9 @@ class ManagerTest(trove_testtools.TestCase):
                 apply_overrides_on_prepare=MagicMock(
                     side_effect=expected_failure
                 )):
+            expected_msg = encodeutils.exception_to_unicode(expected_failure)
             self.assertRaisesRegexp(
-                Exception, expected_failure.message,
+                Exception, expected_msg,
                 self.manager.prepare,
                 self.context, packages, databases, memory_mb, users,
                 device_path, mount_point, backup_info, config_contents,