EPF Cohort 3 Dev Update 8 (pavignol)

This week's update will be relatively short since there are not many endpoints to implement on my end, and some of the endpoints that I have implemented are blocked on PRs that haven't been merged yet.

Added Capella support to the ProposeBeaconBlock and GetBeaconBlock REST API implementations

Originally, when I added ProposeBeaconBlock and GetBeaconBlock, I wasn't able to add support for Capella since the functionality wasn't ready yet on the beacon node side, and therefore there wasn't even a gRPC implementation on the validator side either. But since the Prysm team has been working hard on implementating withdrawals, it was time to revisit those 2 endpoints and add the missing functionality.

Adding Capella support was pretty easy since I have already written all of the boilerplate code, heavylifting and tests a few weeks ago for Bellatrix, so all I needed to do was code the conversion of the withdrawals array between the gRPC and the REST API JSON structs, which looks like this:

func jsonifyWithdrawals(withdrawals []*enginev1.Withdrawal) []*apimiddleware.WithdrawalJson {
	jsonWithdrawals := make([]*apimiddleware.WithdrawalJson, len(withdrawals))
	for index, withdrawal := range withdrawals {
		jsonWithdrawals[index] = &apimiddleware.WithdrawalJson{
			WithdrawalIndex:  strconv.FormatUint(withdrawal.Index, 10),
			ValidatorIndex:   strconv.FormatUint(uint64(withdrawal.ValidatorIndex), 10),
			ExecutionAddress: hexutil.Encode(withdrawal.Address),
			Amount:           strconv.FormatUint(withdrawal.Amount, 10),
		}
	}
	return jsonWithdrawals
}

func convertWithdrawalsToProto(jsonWithdrawals []*apimiddleware.WithdrawalJson) ([]*enginev1.Withdrawal, error) {
	withdrawals := make([]*enginev1.Withdrawal, len(jsonWithdrawals))

	for index, jsonWithdrawal := range jsonWithdrawals {
		if jsonWithdrawal == nil {
			return nil, errors.Errorf("withdrawal at index `%d` is nil", index)
		}

		withdrawalIndex, err := strconv.ParseUint(jsonWithdrawal.WithdrawalIndex, 10, 64)
		if err != nil {
			return nil, errors.Wrapf(err, "failed to parse withdrawal index `%s`", jsonWithdrawal.WithdrawalIndex)
		}

		validatorIndex, err := strconv.ParseUint(jsonWithdrawal.ValidatorIndex, 10, 64)
		if err != nil {
			return nil, errors.Wrapf(err, "failed to parse validator index `%s`", jsonWithdrawal.ValidatorIndex)
		}

		executionAddress, err := hexutil.Decode(jsonWithdrawal.ExecutionAddress)
		if err != nil {
			return nil, errors.Wrapf(err, "failed to decode execution address `%s`", jsonWithdrawal.ExecutionAddress)
		}

		amount, err := strconv.ParseUint(jsonWithdrawal.Amount, 10, 64)
		if err != nil {
			return nil, errors.Wrapf(err, "failed to parse withdrawal amount `%s`", jsonWithdrawal.Amount)
		}

		withdrawals[index] = &enginev1.Withdrawal{
			Index:          withdrawalIndex,
			ValidatorIndex: types.ValidatorIndex(validatorIndex),
			Address:        executionAddress,
			Amount:         amount,
		}
	}

	return withdrawals, nil
}

Update on the PRs

Last week I started publishing updates on the state of the endpoints, so I thought I would keep doing it until the end of the project. Not many PRs were merged this week since our mentor was still on vacation, but other members of the Prysm team pitched in so we were able to merged a few PRs (the ones in bold):

Legend:

Symbol	State
	Not ready for PR
	PR opened
	Merged into develop

Done	Owner	Endpoint
	pavignol	GetDuties
	pavignol	GetBeaconBlock
	pavignol	ProposeBeaconBlock
	pavignol	PrepareBeaconProposer
	pavignol	GetAttestationData
	dhruv	ProposeAttestation
	dhruv	SubmitAggregateSelectionProof
	dhruv	SubmitSignedAggregateSelectionProof
	pavignol	ProposeExit
	pavignol	SubscribeCommitteeSubnets
	manu	SubmitValidatorRegistrations
	manu	ValidatorIndex
	manu	ValidatorStatus
	manu	MultipleValidatorStatus
	pavignol	SubmitSignedContributionAndProof
	manu	SubmitSyncMessage
	dhruv	GetSyncSubcommitteeIndex
	dhruv	GetSyncMessageBlockRoot
	pavignol	StreamDuties
	pavignol	WaitForChainStart
	manu	WaitForActivation
	pavignol	StreamBlocksAltair
	pavignol	DomainData
	manu	GetFeeRecipientByPubKey
	manu	CheckDoppelGanger
	dhruv	GetSyncCommitteeContribution