Implement ProduceAttestationData in the validator API (#9271)

* functionality

* test

* build file

Co-authored-by: Raul Jordan <raul@prysmaticlabs.com>

beacon-chain/rpc/apimiddleware/endpoint_factory.go

@@ -50,6 +50,7 @@ func (f *BeaconEndpointFactory) Paths() []string {
 		"/eth/v1/validator/duties/attester/{epoch}",
 		"/eth/v1/validator/duties/proposer/{epoch}",
 		"/eth/v1/validator/blocks/{slot}",
+		"/eth/v1/validator/attestation_data",
 		"/eth/v1/validator/aggregate_attestation",
 	}
 }
@@ -258,6 +259,13 @@ func (f *BeaconEndpointFactory) Create(path string) (*gateway.Endpoint, error) {
 			GetResponse:        &produceBlockResponseJson{},
 			RequestURLLiterals: []string{"slot"},
 			RequestQueryParams: []gateway.QueryParam{{Name: "randao_reveal", Hex: true}, {Name: "graffiti", Hex: true}},
+			Err:                &gateway.DefaultErrorJson{},
+		}
+	case "/eth/v1/validator/attestation_data":
+		endpoint = gateway.Endpoint{
+			GetResponse:        &produceAttestationDataResponseJson{},
+			RequestQueryParams: []gateway.QueryParam{{Name: "slot"}, {Name: "committee_index"}},
+			Err:                &gateway.DefaultErrorJson{},
 		}
 	case "/eth/v1/validator/aggregate_attestation":
 		endpoint = gateway.Endpoint{

beacon-chain/rpc/apimiddleware/structs.go

@@ -196,6 +196,11 @@ type produceBlockResponseJson struct {
 	Data *beaconBlockJson `json:"data"`
 }
 
+// produceAttestationDataResponseJson is used in /validator/attestation_data API endpoint.
+type produceAttestationDataResponseJson struct {
+	Data *attestationDataJson `json:"data"`
+}
+
 // aggregateAttestationResponseJson is used in /validator/aggregate_attestation API endpoint.
 type aggregateAttestationResponseJson struct {
 	Data *attestationJson `json:"data"`

beacon-chain/rpc/eth/v1/validator/BUILD.bazel

@@ -35,6 +35,7 @@ go_test(
     embed = [":go_default_library"],
     deps = [
         "//beacon-chain/blockchain/testing:go_default_library",
+        "//beacon-chain/cache:go_default_library",
         "//beacon-chain/core/blocks:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
         "//beacon-chain/core/state:go_default_library",
@@ -42,6 +43,7 @@ go_test(
         "//beacon-chain/operations/attestations:go_default_library",
         "//beacon-chain/operations/slashings:go_default_library",
         "//beacon-chain/operations/voluntaryexits:go_default_library",
+        "//beacon-chain/p2p/testing:go_default_library",
         "//beacon-chain/powchain/testing:go_default_library",
         "//beacon-chain/rpc/prysm/v1alpha1/validator:go_default_library",
         "//beacon-chain/state/stategen:go_default_library",
@@ -57,5 +59,6 @@ go_test(
         "//shared/testutil/require:go_default_library",
         "@com_github_prysmaticlabs_eth2_types//:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
+        "@org_golang_google_protobuf//proto:go_default_library",
     ],
 )

beacon-chain/rpc/eth/v1/validator/validator.go

@@ -184,7 +184,21 @@ func (vs *Server) ProduceBlock(ctx context.Context, req *v1.ProduceBlockRequest)
 // ProduceAttestationData requests that the beacon node produces attestation data for
 // the requested committee index and slot based on the nodes current head.
 func (vs *Server) ProduceAttestationData(ctx context.Context, req *v1.ProduceAttestationDataRequest) (*v1.ProduceAttestationDataResponse, error) {
-	return nil, errors.New("Unimplemented")
+	ctx, span := trace.StartSpan(ctx, "validatorv1.ProduceAttestationData")
+	defer span.End()
+
+	v1alpha1req := &v1alpha1.AttestationDataRequest{
+		Slot:           req.Slot,
+		CommitteeIndex: req.CommitteeIndex,
+	}
+	v1alpha1resp, err := vs.V1Alpha1Server.GetAttestationData(ctx, v1alpha1req)
+	if err != nil {
+		// We simply return err because it's already of a gRPC error type.
+		return nil, err
+	}
+	attData := migration.V1Alpha1AttDataToV1(v1alpha1resp)
+
+	return &v1.ProduceAttestationDataResponse{Data: attData}, nil
 }
 
 // GetAggregateAttestation aggregates all attestations matching the given attestation data root and slot, returning the aggregated result.

beacon-chain/rpc/eth/v1/validator/validator_test.go

@@ -4,10 +4,12 @@ import (
 	"context"
 	"fmt"
 	"testing"
+	"time"
 
 	types "github.com/prysmaticlabs/eth2-types"
 	"github.com/prysmaticlabs/go-bitfield"
 	mockChain "github.com/prysmaticlabs/prysm/beacon-chain/blockchain/testing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
 	b "github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/state"
@@ -15,6 +17,7 @@ import (
 	"github.com/prysmaticlabs/prysm/beacon-chain/operations/attestations"
 	"github.com/prysmaticlabs/prysm/beacon-chain/operations/slashings"
 	"github.com/prysmaticlabs/prysm/beacon-chain/operations/voluntaryexits"
+	mockp2p "github.com/prysmaticlabs/prysm/beacon-chain/p2p/testing"
 	mockPOW "github.com/prysmaticlabs/prysm/beacon-chain/powchain/testing"
 	v1alpha1validator "github.com/prysmaticlabs/prysm/beacon-chain/rpc/prysm/v1alpha1/validator"
 	"github.com/prysmaticlabs/prysm/beacon-chain/state/stategen"
@@ -28,6 +31,7 @@ import (
 	"github.com/prysmaticlabs/prysm/shared/testutil"
 	"github.com/prysmaticlabs/prysm/shared/testutil/assert"
 	"github.com/prysmaticlabs/prysm/shared/testutil/require"
+	"google.golang.org/protobuf/proto"
 )
 
 func TestGetAttesterDuties(t *testing.T) {
@@ -314,7 +318,7 @@ func TestGetProposerDuties_SyncNotReady(t *testing.T) {
 	assert.ErrorContains(t, "Syncing to latest head, not ready to respond", err)
 }
 
-func TestGetBlock(t *testing.T) {
+func TestProduceBlock(t *testing.T) {
 	db := dbutil.SetupDB(t)
 	ctx := context.Background()
 
@@ -405,6 +409,82 @@ func TestGetBlock(t *testing.T) {
 	assert.DeepEqual(t, expectedAttSlashings, resp.Data.Body.AttesterSlashings)
 }
 
+func TestProduceAttestationData(t *testing.T) {
+	block := testutil.NewBeaconBlock()
+	block.Block.Slot = 3*params.BeaconConfig().SlotsPerEpoch + 1
+	targetBlock := testutil.NewBeaconBlock()
+	targetBlock.Block.Slot = 1 * params.BeaconConfig().SlotsPerEpoch
+	justifiedBlock := testutil.NewBeaconBlock()
+	justifiedBlock.Block.Slot = 2 * params.BeaconConfig().SlotsPerEpoch
+	blockRoot, err := block.Block.HashTreeRoot()
+	require.NoError(t, err, "Could not hash beacon block")
+	justifiedRoot, err := justifiedBlock.Block.HashTreeRoot()
+	require.NoError(t, err, "Could not get signing root for justified block")
+	targetRoot, err := targetBlock.Block.HashTreeRoot()
+	require.NoError(t, err, "Could not get signing root for target block")
+	slot := 3*params.BeaconConfig().SlotsPerEpoch + 1
+	beaconState, err := testutil.NewBeaconState()
+	require.NoError(t, err)
+	require.NoError(t, beaconState.SetSlot(slot))
+	err = beaconState.SetCurrentJustifiedCheckpoint(&ethpb.Checkpoint{
+		Epoch: 2,
+		Root:  justifiedRoot[:],
+	})
+	require.NoError(t, err)
+
+	blockRoots := beaconState.BlockRoots()
+	blockRoots[1] = blockRoot[:]
+	blockRoots[1*params.BeaconConfig().SlotsPerEpoch] = targetRoot[:]
+	blockRoots[2*params.BeaconConfig().SlotsPerEpoch] = justifiedRoot[:]
+	require.NoError(t, beaconState.SetBlockRoots(blockRoots))
+	chainService := &mockChain.ChainService{
+		Genesis: time.Now(),
+	}
+	offset := int64(slot.Mul(params.BeaconConfig().SecondsPerSlot))
+	v1Alpha1Server := &v1alpha1validator.Server{
+		P2P:              &mockp2p.MockBroadcaster{},
+		SyncChecker:      &mockSync.Sync{IsSyncing: false},
+		AttestationCache: cache.NewAttestationCache(),
+		HeadFetcher: &mockChain.ChainService{
+			State: beaconState, Root: blockRoot[:],
+		},
+		FinalizationFetcher: &mockChain.ChainService{
+			CurrentJustifiedCheckPoint: beaconState.CurrentJustifiedCheckpoint(),
+		},
+		TimeFetcher: &mockChain.ChainService{
+			Genesis: time.Now().Add(time.Duration(-1*offset) * time.Second),
+		},
+		StateNotifier: chainService.StateNotifier(),
+	}
+	v1Server := &Server{
+		V1Alpha1Server: v1Alpha1Server,
+	}
+
+	req := &v1.ProduceAttestationDataRequest{
+		CommitteeIndex: 0,
+		Slot:           3*params.BeaconConfig().SlotsPerEpoch + 1,
+	}
+	res, err := v1Server.ProduceAttestationData(context.Background(), req)
+	require.NoError(t, err, "Could not get attestation info at slot")
+
+	expectedInfo := &v1.AttestationData{
+		Slot:            3*params.BeaconConfig().SlotsPerEpoch + 1,
+		BeaconBlockRoot: blockRoot[:],
+		Source: &v1.Checkpoint{
+			Epoch: 2,
+			Root:  justifiedRoot[:],
+		},
+		Target: &v1.Checkpoint{
+			Epoch: 3,
+			Root:  blockRoot[:],
+		},
+	}
+
+	if !proto.Equal(res.Data, expectedInfo) {
+		t.Errorf("Expected attestation info to match, received %v, wanted %v", res, expectedInfo)
+	}
+}
+
 func TestGetAggregateAttestation(t *testing.T) {
 	ctx := context.Background()
 	root1 := bytesutil.PadTo([]byte("root1"), 32)