AggregationConfig restricts formula to a single microgrid

[cwasicki]

What happened?

The definition of the AggregationConfig allows only a single microgrid, which restricts formulas to only components of the same microgrid, see

frequenz-api-reporting/proto/frequenz/api/reporting/v1/reporting.proto

Line 123 in a193a53

uint64 microgrid_id = 1;

What did you expect instead?

Formulas should be supported for compontents across multiple microgrids too.

Affected version(s)

No response

Affected part(s)

Protocol buffers (part:proto)

Extra information

Solutions could be:

• Allow multiple microgrids: The service would need mapping to determine the microgrid which each component belongs to.
• Remove MID from the requests: Planned for future anyway, but same mapping needed.
• Include MID with the CID in the formula: Additional complexity in the formulas, undesirable since MIDs are going to be removed.

Note: Since CIDs are unique, MIDs are redundant information. At the moment the MID-CID mapping is still required for the service to work, but can be retrieved from the assets API in future. When available, MIDs are going to be removed from reporting API requests in future.