How to record origin of client requests?

[jpraynaud]

Why

We would like to have the capability to optionally record the origin of a call being made by a client to the aggregator. This will help us monitor the usage being made by the different type of users (Bridges, wallets, ...).

What

How can we add an origin to calls made to the aggregator and compute metrics breakdown by origin?
We want to make sure that the mechanism can not be used to flood the aggregator.

How

• How can we implement the origin token:
  • a whitelist of authorized origin tokens
  • How to configure? Yes, hard coded plus with an optional configuration of the aggregator
  • can we stack multiple tokens (yes with a specific token)
• How can we record the existing metrics with a breakdown by origin token?
• How can we compute aggregated metrics with/without the tokens?
  • in Grafana dashboard
  • in event store (vs difficulty of computation of the aggregated views)
    • breakdown in a unique event?
    • or an event by token?