w3s reload of validator pubkeys

[franjoespejo]

🚀 Feature Request

Description

Prysm implements the w3signer standard https://docs.prylabs.network/docs/wallet/web3signer, but it is unknown when the validator client requests the pubkeys to the w3s. For some w3s implementations, as diva (https://docs.divastaking.net/) the pubkeys array in the response is changing,

Describe the solution you'd like

We would need the validator client to periodically check the pubkeys the w3s is signing for in order to keep it up to date.

Nimbus or Lodestar vc are fetching the pubkeys from the w3s periodically for a given interval, that would be the ideal solution

[james-prysm]

Nimbus or Lodestar vc are fetching the pubkeys from the w3s periodically for a given interval, that would be the ideal solution

is this ask for when a URL is provided? perhaps I didn't fully understand what you meant by checking pubkeys the w3s is signing for meant.

is this an alternative to using the keymanager APis to add and remove keys as needed?

[franjoespejo]

Yes, that's for when a url is provided and would be an alternative to using keymanager APIs.

For more context,
The w3s url with the pubkeys of the validators that is ready to sign for:
https://ethereum.github.io/remote-signing-api/#/Public%20Key/PUBLIC_KEY_LIST

The issue is that most of the validator clients assume the w3s always signs for the same validators, and only retrieve that PUBLIC_KEY_LIST once.

[james-prysm]

I'm not sure if most people use it in that way to use the full list directly, I could be wrong, but I have heard of users using only a subset with multiple validators using the same w3s but different keys in the w3s. I'm not sure if this is a feature we should include yet.

perhaps there should be an API that triggers a refresh of the keys or something, not sure is adding the polling intervals is the best solution yet I could reach out to nimbus or lodestar maybe.

in any case will think more on this