refs #12568
- DI pattern through constructor allows for very clear separation of concerns and makes it easy to extract the class into a separate module
refs #12568
- When the server is in maintenance mode (e.g. during migration) it needs to serve a 503 page. Previously this role was delegated to the "frontend" which tightly coupled server bootup and frontend.
- With a dedicated HTTP application serving up 503 server is no longer coupled to the frontend during maintenance