Add check to limit maximum value of max_rows

Currently 'glance-manage db purge' fails if given a
very large number for max_rows.

Moved and renamed validate_mysql_int() from
glance.common.utils to glance.db.sqlalchemy.api as
_validate_db_int() since it is related to database
only so that it can be used to validate max_rows
for maximum limit.

Closes-Bug: #1543937
Change-Id: Id16694807c180632c1785e9b1ebe8d1c79d885ab

glance/cmd/manage.py

@@ -176,7 +176,10 @@ class DbCommands(object):
         if max_rows < 1:
             sys.exit(_("Minimal rows limit is 1."))
         ctx = context.get_admin_context(show_deleted=True)
-        db_api.purge_deleted_rows(ctx, age_in_days, max_rows)
+        try:
+            db_api.purge_deleted_rows(ctx, age_in_days, max_rows)
+        except exception.Invalid as exc:
+            sys.exit(exc.msg)
 
 
 class DbLegacyCommands(object):

glance/common/utils.py

@@ -548,31 +548,6 @@ def no_4byte_params(f):
     return wrapper
 
 
-def validate_mysql_int(*args, **kwargs):
-    """
-    Make sure that all arguments are less than 2 ** 31 - 1.
-
-    This limitation is introduced because mysql stores INT in 4 bytes.
-    If the validation fails for some argument, exception.Invalid is raised with
-    appropriate information.
-    """
-    max_int = (2 ** 31) - 1
-    for param in args:
-        if param > max_int:
-            msg = _("Value %(value)d out of range, "
-                    "must not exceed %(max)d") % {"value": param,
-                                                  "max": max_int}
-            raise exception.Invalid(msg)
-
-    for param_str in kwargs:
-        param = kwargs.get(param_str)
-        if param and param > max_int:
-            msg = _("'%(param)s' value out of range, "
-                    "must not exceed %(max)d") % {"param": param_str,
-                                                  "max": max_int}
-            raise exception.Invalid(msg)
-
-
 def stash_conf_values():
     """
     Make a copy of some of the current global CONF's settings.

glance/db/sqlalchemy/api.py

@@ -105,6 +105,23 @@ def get_session(autocommit=True, expire_on_commit=False):
                               expire_on_commit=expire_on_commit)
 
 
+def _validate_db_int(**kwargs):
+    """Make sure that all arguments are less than or equal to 2 ** 31 - 1.
+
+    This limitation is introduced because databases stores INT in 4 bytes.
+    If the validation fails for some argument, exception.Invalid is raised with
+    appropriate information.
+    """
+    max_int = (2 ** 31) - 1
+
+    for param_key, param_value in kwargs.items():
+        if param_value and param_value > max_int:
+            msg = _("'%(param)s' value out of range, "
+                    "must not exceed %(max)d.") % {"param": param_key,
+                                                   "max": max_int}
+            raise exception.Invalid(msg)
+
+
 def clear_db_env():
     """
     Unset global configuration variables for database.
@@ -731,8 +748,8 @@ def _validate_image(values, mandatory_status=True):
             raise exception.Invalid(msg)
 
     # validate integer values to eliminate DBError on save
-    utils.validate_mysql_int(min_disk=values.get('min_disk'),
-                             min_ram=values.get('min_ram'))
+    _validate_db_int(min_disk=values.get('min_disk'),
+                     min_ram=values.get('min_ram'))
 
     return values
 
@@ -1273,6 +1290,9 @@ def purge_deleted_rows(context, age_in_days, max_rows, session=None):
     Deletes rows of table images, table tasks and all dependent tables
     according to given age for relevant models.
     """
+    # check max_rows for its maximum limit
+    _validate_db_int(max_rows=max_rows)
+
     session = session or get_session()
     metadata = MetaData(get_engine())
     deleted_age = timeutils.utcnow() - datetime.timedelta(days=age_in_days)

glance/tests/unit/test_glance_manage.py

@@ -56,3 +56,19 @@ class DBCommandsTestCase(test_utils.BaseTestCase):
         expected = ("Invalid int value for max_rows: "
                     "%(max_rows)s") % {'max_rows': max_rows}
         self.assertEqual(expected, ex.code)
+
+    @mock.patch.object(db_api, 'purge_deleted_rows')
+    @mock.patch.object(context, 'get_admin_context')
+    def test_purge_max_rows(self, mock_context, mock_db_purge):
+        mock_context.return_value = self.context
+        value = (2 ** 31) - 1
+        self.commands.purge(age_in_days=1, max_rows=value)
+        mock_db_purge.assert_called_once_with(self.context, 1, value)
+
+    def test_purge_command_exceeded_maximum_rows(self):
+        # value(2 ** 31) is greater than max_rows(2147483647) by 1.
+        value = 2 ** 31
+        ex = self.assertRaises(SystemExit, self.commands.purge, age_in_days=1,
+                               max_rows=value)
+        expected = "'max_rows' value out of range, must not exceed 2147483647."
+        self.assertEqual(expected, ex.code)