Add Business Requirements to Multi-Tenancy Plan Document

[mkurapov]

Context

We should outline the use cases & business requirements for the multi-tenancy project as part of the project planning spec. This would include things like:

• What is the problem the feature is trying to solve?
  • Are there alternatives to the proposed problem?
• What is desired experience for the integrators, administrators & end-users of Rafiki?
• Are there any potential regulatory obligations for this feature?

[golobitch]

• What is the problem the feature is trying to solve?
  Well, the problem is that 3rd parties (and I noticed this at GateHub), will not want to implement / setup / maintain / learn about Rafiki or ILP. So they will not setup Rafiki or maybe they have some regulatory requirements to no expose Rafiki endpoints, but this needs to be behind some authentication like basic auth or maybe even connected to through mTLS,... This is why at GateHub we would like to see that GateHub implements tenant for "integrators" that want to leverage ILP protocol, but not have resources or are constrained with some policies. So GateHub would implement this tenant stuff, and connection to bank network would then be handled by GateHub aka ASE.

• What is desired experience for the integrators, administrators & end-users of Rafiki
  Desired experience: It needs to work like magic :) Without too much additional work,... No change in the existing APIs (everything be backward compatible,...)

• Are there any potential regulatory obligations for this feature?
  Probably, in terms that tenant A cannot see data from other tenant and vice versa. I don't know how is with the database access, because with current design the person with access to database will see data for all tenants