Read Only Middleware

For non service provider deployments of swift, it is conceivable that an organization may want to place limits on the amount of data stored. Budgeting or capacity limitations could lead to a use case where it would be desirable for the entire deployment to be marked as read only, and any requests to write objects or create containers would be denied.

The need for this is made more clear by the fact that when a swift deployment fills up, "bad things happen."

The most logical way to implement this would be with a simple WSGI middleware that could be deployed in this scenario.