[RFE] Return error message with better product differentiation errors

[mallardduck]

Issue

When a user enters a SUSE RegCode for a different Product the error code simply says: "Invalid Reg Code". This is a vague error which via feedback from QA was requested to be improved.

To understand the vague error the user will have to execute a number of steps to go from the Registration with the error back to understanding where the issue started. This takes quite a bit of context unwinding and the process may not be the users first instincts. It would involve:

1. Finding the Registration with an error,
2. Looking up the Registration object's RegCode Secret,
3. Login to SCC,
4. Go to their Products page,
5. Find the code they entered on that list,
6. Review what Products that code includes
7. Find the correct Rancher covering RegCode

Solution

If possible we could try to "lookup" the product type of a code and use that do provide additional error context.
If we had that info, then we could make the error specifically say "The reg code provided is for X and doesn't cover Rancher". The SCC team explained the APIs for this already exist.

[prachidamle]

Possibly needed a security review. Also should be a 2.13.2 or further ticket.

[mallardduck]

Potential Solutions

These solutions only apply to Online mode - for offline mode this issue is moot, or must be solved in a different way so should have a new issue.

Fetch RegCode Product info on Error

As titled, when an error is encountered we do API requests to fetch what Products the RegCode actually covers. We then would need to store this info in the Registration Status somewhere for the Rancher UI (or other Products) to fetch and use as desired.

Fetch RegCode Product Info as part of Registration flow

This tactic would involve fetching the Product Info from the SCC API as early as possible. Then we would store that as metadata on the Reg Code secret. This could be a more ideal option than fetching Product info reactively on Errors only. The Product Metadata about the RegCode would be stored along side the actual RegCode in the secret.

The Rancher UI would have to know how to fetch this info when errors happen to display a more user-friendly error than the one the SCC Operator would see.

Backlog as a future Imperative API Feature

The SCC Operator doesn't have Imperative API support, however other issues have already caused us to consider creating an implementation of an Imperative API for the SCC Operator. If we did this, then potentially that provides a route to give the Rancher UI a more synchronous feeling API to hit for looking up the RegCode Product info. This makes the information and request more ephemeral and the UI would only do it just in time as it needs the info.