Currently when using Rust Rocket framework it is necessary to get your database connection via the controller. Basically the connection is given to your handler from a pre-configured pool. Now we have to pass this connection down into any struct which needs a database connection.
If I would like to separate the concerns of reading from the data store, or potentially multiple data stores if caching is involved as well, then I will have to pass one, or potentially multiple, different connection structs from my handler into the lower layer.
While I am aware that I can encapsulate all of the connections into a single request guard, I am dissatisfied by lack of abstraction. I feel quite strongly that my handler should know nothing about the database in order to keep the concerns as separate as possible.
How would I proceed in Rust to obtain a connection from some shared pool of connections in an object, without usage of request guards and argument drilling?
Note: Terminology may be incorrect due to rather limited experience with Rocket