Prysm gRPC Indexed Attestation Parsing

go.mod

module github.com/rauljordan/attestation-parse

go 1.17

require (
	github.com/golang/protobuf v1.5.2
	github.com/prysmaticlabs/prysm/v2 v2.0.1
	google.golang.org/grpc v1.37.0
)

require (
	github.com/btcsuite/btcd v0.22.0-beta // indirect
	github.com/cespare/xxhash v1.1.0 // indirect
	github.com/cpuguy83/go-md2man/v2 v2.0.0-20190314233015-f79a8a8ca69d // indirect
	github.com/dgraph-io/ristretto v0.0.4-0.20210318174700-74754f61e018 // indirect
	github.com/dustin/go-humanize v1.0.0 // indirect
	github.com/ethereum/go-ethereum v1.9.25 // indirect
	github.com/ferranbt/fastssz v0.0.0-20210905181407-59cf6761a7d5 // indirect
	github.com/golang/groupcache v0.0.0-20200121045136-8c9f03a8e57e // indirect
	github.com/grpc-ecosystem/grpc-gateway/v2 v2.0.1 // indirect
	github.com/herumi/bls-eth-go-binary v0.0.0-20210917013441-d37c07cfda4e // indirect
	github.com/klauspost/cpuid/v2 v2.0.8 // indirect
	github.com/konsorten/go-windows-terminal-sequences v1.0.3 // indirect
	github.com/minio/sha256-simd v1.0.0 // indirect
	github.com/mitchellh/mapstructure v1.4.1 // indirect
	github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826 // indirect
	github.com/pkg/errors v0.9.1 // indirect
	github.com/prysmaticlabs/eth2-types v0.0.0-20210303084904-c9735a06829d // indirect
	github.com/prysmaticlabs/go-bitfield v0.0.0-20210809151128-385d8c5e3fb7 // indirect
	github.com/russross/blackfriday/v2 v2.0.1 // indirect
	github.com/shurcooL/sanitized_anchor_name v1.0.0 // indirect
	github.com/sirupsen/logrus v1.6.0 // indirect
	github.com/supranational/blst v0.3.5 // indirect
	github.com/thomaso-mirodin/intmath v0.0.0-20160323211736-5dc6d854e46e // indirect
	github.com/urfave/cli/v2 v2.3.0 // indirect
	go.opencensus.io v0.23.0 // indirect
	golang.org/x/crypto v0.0.0-20210711020723-a769d52b0f97 // indirect
	golang.org/x/net v0.0.0-20210716203947-853a461950ff // indirect
	golang.org/x/sys v0.0.0-20210630005230-0f9fa26af87c // indirect
	golang.org/x/text v0.3.6 // indirect
	google.golang.org/genproto v0.0.0-20210426193834-eac7f76ac494 // indirect
	google.golang.org/protobuf v1.27.1 // indirect
	gopkg.in/yaml.v2 v2.4.0 // indirect
)

main.go

package main

import (
	"context"
	"fmt"
	"sort"

	"github.com/golang/protobuf/ptypes/empty"
	ethpb "github.com/prysmaticlabs/prysm/v2/proto/prysm/v1alpha1"
	"github.com/prysmaticlabs/prysm/v2/proto/prysm/v1alpha1/attestation"
	"google.golang.org/grpc"
)

func main() {
	client, err := grpc.Dial("localhost:4000", grpc.WithInsecure())
	if err != nil {
		panic(err)
	}
	beaconClient := ethpb.NewBeaconChainClient(client)
	ctx := context.Background()
	head, err := beaconClient.GetChainHead(ctx, &empty.Empty{})
	if err != nil {
		panic(err)
	}
	fmt.Printf("Head slot %d, epoch %d\n", head.HeadSlot, head.HeadEpoch)
	fmt.Println("Fetching beacon committees (this can take a min)...")
	committeesResp, err := beaconClient.ListBeaconCommittees(ctx, &ethpb.ListCommitteesRequest{
		QueryFilter: &ethpb.ListCommitteesRequest_Epoch{
			Epoch: head.HeadEpoch,
		},
	})
	slots := make([]uint64, 0)
	for k := range committeesResp.Committees {
		slots = append(slots, k)
	}
	sort.SliceStable(slots, func(i, j int) bool {
		return slots[i] < slots[j]
	})
	fmt.Printf("Committee lowest slot %d and highest %d\n", slots[0], slots[len(slots)-1])
	fmt.Printf("Fetching beacon blocks for head epoch %d...\n", head.HeadEpoch)
	blocksResp, err := beaconClient.ListBeaconBlocks(ctx, &ethpb.ListBlocksRequest{
		QueryFilter: &ethpb.ListBlocksRequest_Epoch{
			Epoch: head.HeadEpoch,
		},
	})
	// TODO: Get the last few epochs worth of committees, as some attestations could be from committees in past epochs.
	fmt.Printf("Found %d blocks in epoch %d\n", len(blocksResp.BlockContainers), head.HeadEpoch)
	attestationsInEpoch := make([]*ethpb.Attestation, 0)
	for _, blk := range blocksResp.BlockContainers {
		cntr, ok := blk.Block.(*ethpb.BeaconBlockContainer_AltairBlock)
		if !ok {
			panic("not an altair block")
		}
		signedBlock := cntr.AltairBlock
		block := signedBlock.Block
		attestationsInEpoch = append(attestationsInEpoch, block.Body.Attestations...)
	}
	fmt.Printf("Found %d attestations in epoch %d\n", len(attestationsInEpoch), head.HeadEpoch)
	indexedAttestations := make([]*ethpb.IndexedAttestation, len(attestationsInEpoch))
	for _, att := range attestationsInEpoch {
		committeesForSlot, ok := committeesResp.Committees[uint64(att.Data.Slot)]
		if !ok {
			// We should get at least 2 epochs worth of committees so this should not happen.
			continue
		}
		committeeForAttestation := committeesForSlot.Committees[att.Data.CommitteeIndex]
		indexedAtt, err := attestation.ConvertToIndexed(ctx, att, committeeForAttestation.ValidatorIndices)
		if err != nil {
			panic(err)
		}
		indexedAttestations = append(indexedAttestations, indexedAtt)
	}
	fmt.Printf("Converted %d attestations to indexed form\n", len(indexedAttestations))
	_ = indexedAttestations // Do something with the validator indices within.
}