exception: make message mandatory in DbMigrationError and deprecates it

An exception message with None as an error message is not really useful. Since
DbMigrationError is also wrongly written with a lower case b whereas everything
else has a major B, let's create a new correct class and use it.

debtcollector is used to deprecate the old one, and inheritance makes sure the
current code works.

Change-Id: Id9a477aff38afd5b664b75a549ad561f4c24b6f0

1 files changed, 14 insertions, 0 deletions

diff --git a/oslo_db/exception.py b/oslo_db/exception.py
index c5e0fa9..ba7dde0 100644
--- a/oslo_db/exception.py
+++ b/oslo_db/exception.py
@@ -171,6 +171,20 @@ class DbMigrationError(DBError):
         super(DbMigrationError, self).__init__(message)
 
 
+class DBMigrationError(DbMigrationError):
+
+    """Wrapped migration specific exception.
+
+    Raised when migrations couldn't be completed successfully.
+    """
+    def __init__(self, message):
+        super(DBMigrationError, self).__init__(message)
+
+
+debtcollector.removals.removed_class(DbMigrationError,
+                                     replacement=DBMigrationError)
+
+
 class DBConnectionError(DBError):
 
     """Wrapped connection specific exception.