## Issue Addressed
Relates to https://github.com/sigp/lighthouse/issues/3416
## Proposed Changes
- Add an `OfflineOnFailure` enum to the `first_success` method for querying beacon nodes so that a val registration request failure from the BN -> builder does not result in the BN being marked offline. This seems important because these failures could be coming directly from a connected relay and actually have no bearing on BN health. Other messages that are sent to a relay have a local fallback so shouldn't result in errors
- Downgrade the following log to a `WARN`
```
ERRO Unable to publish validator registrations to the builder network, error: All endpoints failed https://BN_B => RequestFailed(ServerMessage(ErrorMessage { code: 500, message: "UNHANDLED_ERROR: BuilderMissing", stacktraces: [] })), https://XXXX/ => Unavailable(Offline), [omitted]
```
## Additional Info
I think this change at least improves the UX of having a VC connected to some builder and some non-builder beacon nodes. I think we need to balance potentially alerting users that there is a BN <> VC misconfiguration and also allowing this type of fallback to work.
If we want to fully support this type of configuration we may want to consider adding a flag `--builder-beacon-nodes` and track whether a VC should be making builder queries on a per-beacon node basis. But I think the changes in this PR are independent of that type of extension.
PS: Sorry for the big diff here, it's mostly formatting changes after I added a new arg to a bunch of methods calls.
Co-authored-by: realbigsean <sean@sigmaprime.io>
## Issue Addressed
#2953
## Proposed Changes
Adds empty local validator check.
## Additional Info
Two other options:
- add check inside `local_index` collection. Instead of after collection.
- Move `local_index` collection to the beginning of the `poll_sync_committee_duties` function and combine sync committee with altair fork check.
[EIP-3030]: https://eips.ethereum.org/EIPS/eip-3030
[Web3Signer]: https://consensys.github.io/web3signer/web3signer-eth2.html
## Issue Addressed
Resolves#2498
## Proposed Changes
Allows the VC to call out to a [Web3Signer] remote signer to obtain signatures.
## Additional Info
### Making Signing Functions `async`
To allow remote signing, I needed to make all the signing functions `async`. This caused a bit of noise where I had to convert iterators into `for` loops.
In `duties_service.rs` there was a particularly tricky case where we couldn't hold a write-lock across an `await`, so I had to first take a read-lock, then grab a write-lock.
### Move Signing from Core Executor
Whilst implementing this feature, I noticed that we signing was happening on the core tokio executor. I suspect this was causing the executor to temporarily lock and occasionally trigger some HTTP timeouts (and potentially SQL pool timeouts, but I can't verify this). Since moving all signing into blocking tokio tasks, I noticed a distinct drop in the "atttestations_http_get" metric on a Prater node:
I think this graph indicates that freeing the core executor allows the VC to operate more smoothly.
### Refactor TaskExecutor
I noticed that the `TaskExecutor::spawn_blocking_handle` function would fail to spawn tasks if it were unable to obtain handles to some metrics (this can happen if the same metric is defined twice). It seemed that a more sensible approach would be to keep spawning tasks, but without metrics. To that end, I refactored the function so that it would still function without metrics. There are no other changes made.
## TODO
- [x] Restructure to support multiple signing methods.
- [x] Add calls to remote signer from VC.
- [x] Documentation
- [x] Test all endpoints
- [x] Test HTTPS certificate
- [x] Allow adding remote signer validators via the API
- [x] Add Altair support via [21.8.1-rc1](https://github.com/ConsenSys/web3signer/releases/tag/21.8.1-rc1)
- [x] Create issue to start using latest version of web3signer. (See #2570)
## Notes
- ~~Web3Signer doesn't yet support the Altair fork for Prater. See https://github.com/ConsenSys/web3signer/issues/423.~~
- ~~There is not yet a release of Web3Signer which supports Altair blocks. See https://github.com/ConsenSys/web3signer/issues/391.~~
## Proposed Changes
* Implement the validator client and HTTP API changes necessary to support Altair
Co-authored-by: realbigsean <seananderson33@gmail.com>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
