Split get_data_column_sidecars parameters

[jtraglia]

In the data-availability-sampling channel in the Eth R&D server, Potuz brought this up:

I have a little problem with peer DAS that it's not specification related but rather implementation. In many parts of Prysm code we assume that the commitments come in the beacon block. Within ePBS this is not true. Working on top of Electra requires us to change the DA code to take the commitments instead of the blocks on most helpers. Peer DAS is a complication cause clients keep a separate branch for it. So ePBS is explicitly in conflict with peer DAS at the time of merging. Could it be possible to clean the spec to make minimal assumptions that the commitments are in blocks and have the helpers take them directly rather than accessing them from blocks?

@potuz would something like this work for you? Only get_data_column_sidecars needs to change, right?

Thanks for getting back to me Justin, yeah those changes are the kind of things that I'd like to see. I Don't follow the peer das spec to know where else it appears and surely clients will have their own separate signatures on implementations. I would just ask to err on the safe side and take the commitments as you did there (and if it appears somewhere else). This will at least make my life easier when I need to rebase 7732 on top of peer DAS. Otherwise you'll have me pushing to ship both together 😝

I believe get_data_column_sidecars is the only pain-point. This PR splits the signed_block parameter into three: signed_block_header, blob_kzg_commitments , and kzg_commitments_inclusion_proof .

[ralexstokes]

this feels like something we don't necessarily need to reify in the specs (as clients are free to implement it this way today w/ Deneb, later in Electra, and beyond) but if it is going to substantially streamline development elsewhere I'd accept it

(although im also not sure how much it will streamline if all we have to do is change this one function signature)

[ppopth]

Can you point specifically where in the ePBS so that the description will be more complete?

Working on top of Electra requires us to change the DA code to take the commitments instead of the blocks on most helpers

Could you give some examples of such DA code?

[jtraglia]

Could you give some examples of such DA code?

cc @potuz

[jtraglia]

This has gone stale. Going to close it. Happy to reopen if there's a need.