dev: query chain_id from Kakarot instead of computing it in the RPC to reduce probability of divergence

[Eikix]

Describe the enhancement request

in the RPC, we currently use the following formula to compute the kakarot chain id:

• get connected starknet chain's chain id
• do chain id modulo MAX_SAFE_CHAIN_ID
• store this value in the context of RPC

while this is currently valid, a new PR from kakarot sets the chain id of future kakarot deployments as <LEDGER_MAX_CHAIN_ID

Describe Preferred Solution

to limit chances of divergence between rpc code and kakarot code, RPC should query kakarot for its chain id with the eth_chain_id view entrypoint from kakarot at startup

[elielnfinic]

I will be happy to work on this

[augustin-v]

Hello, I would love to work on this. I've just contributed to implementing a l1 gas prices sampling oracle in Katana so I think I can tackle this issue.
I'll make sure to communicate if I encounter any problem

[Eikix]

Hi @augustin-v @elielnfinic
We're pausing commits to the RPC layer for now as we're restructuring the project!
Kindly expect opportunity to contribute to be paused for a few months.
Thanks:)

[elielnfinic]

Good, any areas we can look at on kkrt?