Add utility of boolean value parser

We parse the boolean value from string in dict with identical
logic in different areas, it's reasonable to add an util function
to cover this.

Change-Id: Id54029e2e4a0dd2f2093e6ef2583a9cada84c540

manila/api/v2/shares.py

@@ -13,7 +13,6 @@
 #    License for the specific language governing permissions and limitations
 #    under the License.
 
-from oslo_utils import strutils
 import six
 import webob
 from webob import exc
@@ -30,6 +29,7 @@ from manila import db
 from manila import exception
 from manila.i18n import _
 from manila import share
+from manila import utils
 
 
 class ShareController(shares.ShareMixin,
@@ -99,44 +99,16 @@ class ShareController(shares.ShareMixin,
         except KeyError:
             raise exc.HTTPBadRequest(explanation=_("Must specify 'host'."))
 
-        force_host_assisted_migration = params.get(
-            'force_host_assisted_migration', False)
-        try:
-            force_host_assisted_migration = strutils.bool_from_string(
-                force_host_assisted_migration, strict=True)
-        except ValueError:
-            msg = _("Invalid value %s for 'force_host_assisted_migration'. "
-                    "Expecting a boolean.") % force_host_assisted_migration
-            raise exc.HTTPBadRequest(explanation=msg)
+        force_host_assisted_migration = utils.get_bool_from_api_params(
+            'force_host_assisted_migration', params)
 
         new_share_network = None
         new_share_type = None
 
-        preserve_metadata = params.get('preserve_metadata', True)
-        try:
-            preserve_metadata = strutils.bool_from_string(
-                preserve_metadata, strict=True)
-        except ValueError:
-            msg = _("Invalid value %s for 'preserve_metadata'. "
-                    "Expecting a boolean.") % preserve_metadata
-            raise exc.HTTPBadRequest(explanation=msg)
-
-        writable = params.get('writable', True)
-        try:
-            writable = strutils.bool_from_string(writable, strict=True)
-        except ValueError:
-            msg = _("Invalid value %s for 'writable'. "
-                    "Expecting a boolean.") % writable
-            raise exc.HTTPBadRequest(explanation=msg)
-
-        nondisruptive = params.get('nondisruptive', False)
-        try:
-            nondisruptive = strutils.bool_from_string(
-                nondisruptive, strict=True)
-        except ValueError:
-            msg = _("Invalid value %s for 'nondisruptive'. "
-                    "Expecting a boolean.") % nondisruptive
-            raise exc.HTTPBadRequest(explanation=msg)
+        preserve_metadata = utils.get_bool_from_api_params('preserve_metadata',
+                                                           params, True)
+        writable = utils.get_bool_from_api_params('writable', params, True)
+        nondisruptive = utils.get_bool_from_api_params('nondisruptive', params)
 
         new_share_network_id = params.get('new_share_network_id', None)
         if new_share_network_id:

manila/tests/test_utils.py

@@ -25,6 +25,7 @@ import mock
 from oslo_config import cfg
 from oslo_utils import timeutils
 import paramiko
+from webob import exc
 
 import manila
 from manila.common import constants
@@ -378,6 +379,56 @@ class CidrToNetmaskTestCase(test.TestCase):
         self.assertRaises(exception.InvalidInput, utils.cidr_to_netmask, cidr)
 
 
+@ddt.ddt
+class ParseBoolValueTestCase(test.TestCase):
+
+    @ddt.data(
+        ('t', True),
+        ('on', True),
+        ('1', True),
+        ('false', False),
+        ('n', False),
+        ('no', False),
+        ('0', False),)
+    @ddt.unpack
+    def test_bool_with_valid_string(self, string, value):
+        fake_dict = {'fake_key': string}
+        result = utils.get_bool_from_api_params('fake_key', fake_dict)
+        self.assertEqual(value, result)
+
+    @ddt.data('None', 'invalid', 'falses')
+    def test_bool_with_invalid_string(self, string):
+        fake_dict = {'fake_key': string}
+        self.assertRaises(exc.HTTPBadRequest,
+                          utils.get_bool_from_api_params,
+                          'fake_key', fake_dict)
+
+    @ddt.data('undefined', None)
+    def test_bool_with_key_not_found_raise_error(self, def_val):
+        fake_dict = {'fake_key1': 'value1'}
+        self.assertRaises(exc.HTTPBadRequest,
+                          utils.get_bool_from_api_params,
+                          'fake_key2',
+                          fake_dict,
+                          def_val)
+
+    @ddt.data((False, False, False),
+              (True, True, False),
+              ('true', True, False),
+              ('false', False, False),
+              ('undefined', 'undefined', False),
+              (False, False, True),
+              ('true', True, True))
+    @ddt.unpack
+    def test_bool_with_key_not_found(self, def_val, expected, strict):
+        fake_dict = {'fake_key1': 'value1'}
+        invalid_default = utils.get_bool_from_api_params('fake_key2',
+                                                         fake_dict,
+                                                         def_val,
+                                                         strict)
+        self.assertEqual(expected, invalid_default)
+
+
 @ddt.ddt
 class IsValidIPVersion(test.TestCase):
     """Test suite for function 'is_valid_ip_address'."""

manila/utils.py

@@ -38,10 +38,12 @@ from oslo_config import cfg
 from oslo_log import log
 from oslo_utils import importutils
 from oslo_utils import netutils
+from oslo_utils import strutils
 from oslo_utils import timeutils
 import paramiko
 import retrying
 import six
+from webob import exc
 
 from manila.common import constants
 from manila.db import api as db_api
@@ -461,6 +463,26 @@ def retry(exception, interval=1, retries=10, backoff_rate=2,
     return _decorator
 
 
+def get_bool_from_api_params(key, params, default=False, strict=True):
+    """Parse bool value from request params.
+
+    HTTPBadRequest will be directly raised either of the cases below:
+    1. invalid bool string was found by key(with strict on).
+    2. key not found while default value is invalid(with strict on).
+    """
+    param = params.get(key, default)
+    try:
+        param = strutils.bool_from_string(param,
+                                          strict=strict,
+                                          default=default)
+    except ValueError:
+        msg = _('Invalid value %(param)s for %(param_string)s. '
+                'Expecting a boolean.') % {'param': param,
+                                           'param_string': key}
+        raise exc.HTTPBadRequest(explanation=msg)
+    return param
+
+
 def require_driver_initialized(func):
     @functools.wraps(func)
     def wrapper(self, *args, **kwargs):