[FRQ] Optionally pass in dependencies

[chriswessels]

Problem statement
It is useful to be able to know which dependencies are attached to a given POI attestation. This would help us root cause divergence issues.

Expectation proposal
Imagine an Indexer could pass any number of supported dependencies as configuration. If this were a flag, it could take the form:

--dep <type>:<id>=<uri>

poi-radio --dep postgresql:primary=postgresql://host:5432 --dep chain:mainnet=http://geth:8545

For each provided flag, handler logic could be defined for the type that allows POI Radio to extract the version. For example, for the chain type, the POI radio could call web3_clientVersion at the provided uri to get the client version. A SQL statement could similarly be executed to get PostgreSQL version.

The resulting dependency information could be attached to POI messages.

Alternative considerations
None, but please comment with ideas.

[hopeyen]

Do you think it would make sense for all Graphcast message? or specific to POI radio? Could this be only optionally passed in or something required upon radio start-up?

[chriswessels]

Do you think it would make sense for all Graphcast message?

I don't think so. Dependencies are specifically relevant to POI attestations because they are data determinism inputs. So specific to POI Radio + POI messages.

Could this be only optionally passed in or something required upon radio start-up?

I had imagined that this would be entirely optional. If required, it'd significantly increase UX friction, and there are also many different configurations of Indexer and therefore dependencies (e.g. 1 chain vs 20 chains). So my proposal would be that the POI Radio supports a variety of dependency "types", like EIP155 chains, and the Indexer can pass in as many as they want. The POI Radio can then query the chain for both the client version information, and chain ID, and match these with the deployment's network.

[hopeyen]

Moved to graphops/subgraph-radio#9