Implement Chain Head Stream & Naming Consistency (#4160)

* include stream chain head mock
* uncomment test
* stream chain head implemented
* remove imports
* chain head stream test
* include stream test with mockgen
* test now passes
* checkin items
* stream tests all passing
* rem learn
* fix up fork checker
* add stream ctx
* gaz, fix test
* fix broken test
* Merge branch 'master' into chain-head-stream
* include context in chain head stream happy path test
* Merge branch 'master' into chain-head-stream
* Merge branch 'master' into chain-head-stream
* Merge refs/heads/master into chain-head-stream
* Merge refs/heads/master into chain-head-stream

WORKSPACE

@@ -1202,7 +1202,7 @@ go_repository(
 
 go_repository(
     name = "com_github_prysmaticlabs_ethereumapis",
-    commit = "8a69b37df2264eb58b0b0cef5ba25ae9af2d8732",
+    commit = "23585b69a8b4113742948e3e266ceece844518a6",
     importpath = "github.com/prysmaticlabs/ethereumapis",
     patch_args = ["-p1"],
     patches = [

beacon-chain/rpc/beacon/BUILD.bazel

@@ -50,13 +50,16 @@ go_test(
     deps = [
         "//beacon-chain/blockchain/testing:go_default_library",
         "//beacon-chain/core/helpers:go_default_library",
+        "//beacon-chain/core/statefeed:go_default_library",
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/db/testing:go_default_library",
         "//beacon-chain/operations/testing:go_default_library",
+        "//beacon-chain/rpc/testing:go_default_library",
         "//proto/beacon/p2p/v1:go_default_library",
         "//shared/params:go_default_library",
         "@com_github_gogo_protobuf//proto:go_default_library",
         "@com_github_gogo_protobuf//types:go_default_library",
+        "@com_github_golang_mock//gomock:go_default_library",
         "@com_github_prysmaticlabs_ethereumapis//eth/v1alpha1:go_default_library",
         "@com_github_prysmaticlabs_go_bitfield//:go_default_library",
         "@com_github_prysmaticlabs_go_ssz//:go_default_library",

beacon-chain/rpc/beacon/blocks.go

@@ -8,6 +8,7 @@ import (
 	ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
 	"github.com/prysmaticlabs/go-ssz"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/statefeed"
 	"github.com/prysmaticlabs/prysm/beacon-chain/db/filters"
 	"github.com/prysmaticlabs/prysm/shared/bytesutil"
 	"github.com/prysmaticlabs/prysm/shared/pagination"
@@ -175,6 +176,36 @@ func (bs *Server) ListBlocks(
 // This includes the head block slot and root as well as information about
 // the most recent finalized and justified slots.
 func (bs *Server) GetChainHead(ctx context.Context, _ *ptypes.Empty) (*ethpb.ChainHead, error) {
+	return bs.chainHeadRetrieval(ctx)
+}
+
+// StreamChainHead to clients every single time the head block and state of the chain change.
+func (bs *Server) StreamChainHead(_ *ptypes.Empty, stream ethpb.BeaconChain_StreamChainHeadServer) error {
+	stateChannel := make(chan *statefeed.Event, 1)
+	stateSub := bs.StateNotifier.StateFeed().Subscribe(stateChannel)
+	defer stateSub.Unsubscribe()
+	for {
+		select {
+		case event := <-stateChannel:
+			if event.Type == statefeed.BlockProcessed {
+				res, err := bs.chainHeadRetrieval(bs.Ctx)
+				if err != nil {
+					return status.Errorf(codes.Internal, "Could not retrieve chain head: %v", err)
+				}
+				return stream.Send(res)
+			}
+		case <-stateSub.Err():
+			return status.Error(codes.Aborted, "Subscriber closed, exiting goroutine")
+		case <-bs.Ctx.Done():
+			return status.Error(codes.Canceled, "Context canceled")
+		case <-stream.Context().Done():
+			return status.Error(codes.Canceled, "Context canceled")
+		}
+	}
+}
+
+// Retrieve chain head information from the DB and the current beacon state.
+func (bs *Server) chainHeadRetrieval(ctx context.Context) (*ethpb.ChainHead, error) {
 	headState, err := bs.HeadFetcher.HeadState(ctx)
 	if err != nil {
 		return nil, status.Errorf(codes.Internal, "Could not get head state: %v", err)
@@ -191,34 +222,34 @@ func (bs *Server) GetChainHead(ctx context.Context, _ *ptypes.Empty) (*ethpb.Cha
 	if err != nil || b == nil {
 		return nil, status.Error(codes.Internal, "Could not get finalized block")
 	}
-	finalizedBlockSlot := b.Slot
+	finalizedSlot := b.Slot
 
 	justifiedCheckpoint := headState.CurrentJustifiedCheckpoint
 	b, err = bs.BeaconDB.Block(ctx, bytesutil.ToBytes32(justifiedCheckpoint.Root))
 	if err != nil || b == nil {
 		return nil, status.Error(codes.Internal, "Could not get justified block")
 	}
-	justifiedBlockSlot := b.Slot
+	justifiedSlot := b.Slot
 
 	prevJustifiedCheckpoint := headState.PreviousJustifiedCheckpoint
 	b, err = bs.BeaconDB.Block(ctx, bytesutil.ToBytes32(prevJustifiedCheckpoint.Root))
 	if err != nil || b == nil {
 		return nil, status.Error(codes.Internal, "Could not get prev justified block")
 	}
-	prevJustifiedBlockSlot := b.Slot
+	prevJustifiedSlot := b.Slot
 
 	return &ethpb.ChainHead{
-		HeadBlockSlot:              headBlock.Slot,
-		HeadBlockEpoch:             helpers.SlotToEpoch(headBlock.Slot),
+		HeadSlot:                   headBlock.Slot,
+		HeadEpoch:                  helpers.SlotToEpoch(headBlock.Slot),
 		HeadBlockRoot:              headBlockRoot[:],
-		FinalizedBlockRoot:         finalizedCheckpoint.Root,
-		FinalizedBlockSlot:         finalizedBlockSlot,
+		FinalizedSlot:              finalizedSlot,
 		FinalizedEpoch:             finalizedCheckpoint.Epoch,
-		JustifiedBlockRoot:         justifiedCheckpoint.Root,
-		JustifiedBlockSlot:         justifiedBlockSlot,
+		FinalizedBlockRoot:         finalizedCheckpoint.Root,
+		JustifiedSlot:              justifiedSlot,
 		JustifiedEpoch:             justifiedCheckpoint.Epoch,
-		PreviousJustifiedBlockRoot: prevJustifiedCheckpoint.Root,
-		PreviousJustifiedSlot:      prevJustifiedBlockSlot,
+		JustifiedBlockRoot:         justifiedCheckpoint.Root,
+		PreviousJustifiedSlot:      prevJustifiedSlot,
 		PreviousJustifiedEpoch:     prevJustifiedCheckpoint.Epoch,
+		PreviousJustifiedBlockRoot: prevJustifiedCheckpoint.Root,
 	}, nil
 }

beacon-chain/rpc/beacon/blocks_test.go

@@ -9,10 +9,15 @@ import (
 	"testing"
 
 	"github.com/gogo/protobuf/proto"
+	ptypes "github.com/gogo/protobuf/types"
+	"github.com/golang/mock/gomock"
 	ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
 	"github.com/prysmaticlabs/go-ssz"
 	mock "github.com/prysmaticlabs/prysm/beacon-chain/blockchain/testing"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
+	"github.com/prysmaticlabs/prysm/beacon-chain/core/statefeed"
 	dbTest "github.com/prysmaticlabs/prysm/beacon-chain/db/testing"
+	mockRPC "github.com/prysmaticlabs/prysm/beacon-chain/rpc/testing"
 	pbp2p "github.com/prysmaticlabs/prysm/proto/beacon/p2p/v1"
 	"github.com/prysmaticlabs/prysm/shared/params"
 )
@@ -370,13 +375,13 @@ func TestServer_GetChainHead(t *testing.T) {
 		t.Errorf("Wanted PreviousJustifiedSlot: %d, got: %d",
 			3, head.PreviousJustifiedSlot)
 	}
-	if head.JustifiedBlockSlot != 2 {
+	if head.JustifiedSlot != 2 {
 		t.Errorf("Wanted JustifiedSlot: %d, got: %d",
-			2, head.JustifiedBlockSlot)
+			2, head.JustifiedSlot)
 	}
-	if head.FinalizedBlockSlot != 1 {
+	if head.FinalizedSlot != 1 {
 		t.Errorf("Wanted FinalizedSlot: %d, got: %d",
-			1, head.FinalizedBlockSlot)
+			1, head.FinalizedSlot)
 	}
 	if !bytes.Equal(pjRoot[:], head.PreviousJustifiedBlockRoot) {
 		t.Errorf("Wanted PreviousJustifiedBlockRoot: %v, got: %v",
@@ -391,3 +396,98 @@ func TestServer_GetChainHead(t *testing.T) {
 			fRoot[:], head.FinalizedBlockRoot)
 	}
 }
+
+func TestServer_StreamChainHead_ContextCanceled(t *testing.T) {
+	db := dbTest.SetupDB(t)
+	defer dbTest.TeardownDB(t, db)
+	ctx := context.Background()
+
+	ctx, cancel := context.WithCancel(ctx)
+	chainService := &mock.ChainService{}
+	server := &Server{
+		Ctx:           ctx,
+		StateNotifier: chainService.StateNotifier(),
+		BeaconDB:      db,
+	}
+
+	exitRoutine := make(chan bool)
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+	mockStream := mockRPC.NewMockBeaconChain_StreamChainHeadServer(ctrl)
+	mockStream.EXPECT().Context().Return(ctx)
+	go func(tt *testing.T) {
+		if err := server.StreamChainHead(&ptypes.Empty{}, mockStream); !strings.Contains(err.Error(), "Context canceled") {
+			tt.Errorf("Could not call RPC method: %v", err)
+		}
+		<-exitRoutine
+	}(t)
+	cancel()
+	exitRoutine <- true
+}
+
+func TestServer_StreamChainHead_OnHeadUpdated(t *testing.T) {
+	db := dbTest.SetupDB(t)
+	defer dbTest.TeardownDB(t, db)
+
+	finalizedBlock := &ethpb.BeaconBlock{Slot: 1, ParentRoot: []byte{'A'}}
+	db.SaveBlock(context.Background(), finalizedBlock)
+	fRoot, _ := ssz.SigningRoot(finalizedBlock)
+	justifiedBlock := &ethpb.BeaconBlock{Slot: 2, ParentRoot: []byte{'B'}}
+	db.SaveBlock(context.Background(), justifiedBlock)
+	jRoot, _ := ssz.SigningRoot(justifiedBlock)
+	prevJustifiedBlock := &ethpb.BeaconBlock{Slot: 3, ParentRoot: []byte{'C'}}
+	db.SaveBlock(context.Background(), prevJustifiedBlock)
+	pjRoot, _ := ssz.SigningRoot(prevJustifiedBlock)
+
+	s := &pbp2p.BeaconState{
+		PreviousJustifiedCheckpoint: &ethpb.Checkpoint{Epoch: 3, Root: pjRoot[:]},
+		CurrentJustifiedCheckpoint:  &ethpb.Checkpoint{Epoch: 2, Root: jRoot[:]},
+		FinalizedCheckpoint:         &ethpb.Checkpoint{Epoch: 1, Root: fRoot[:]},
+	}
+	b := &ethpb.BeaconBlock{Slot: s.PreviousJustifiedCheckpoint.Epoch*params.BeaconConfig().SlotsPerEpoch + 1}
+	hRoot, _ := ssz.SigningRoot(b)
+
+	chainService := &mock.ChainService{}
+	server := &Server{
+		Ctx:           context.Background(),
+		HeadFetcher:   &mock.ChainService{Block: b, State: s},
+		BeaconDB:      db,
+		StateNotifier: chainService.StateNotifier(),
+	}
+	exitRoutine := make(chan bool)
+	ctrl := gomock.NewController(t)
+	defer ctrl.Finish()
+	mockStream := mockRPC.NewMockBeaconChain_StreamChainHeadServer(ctrl)
+	mockStream.EXPECT().Context().Return(context.Background())
+	mockStream.EXPECT().Send(
+		&ethpb.ChainHead{
+			HeadSlot:                   b.Slot,
+			HeadEpoch:                  helpers.SlotToEpoch(b.Slot),
+			HeadBlockRoot:              hRoot[:],
+			FinalizedSlot:              1,
+			FinalizedEpoch:             1,
+			FinalizedBlockRoot:         fRoot[:],
+			JustifiedSlot:              2,
+			JustifiedEpoch:             2,
+			JustifiedBlockRoot:         jRoot[:],
+			PreviousJustifiedSlot:      3,
+			PreviousJustifiedEpoch:     3,
+			PreviousJustifiedBlockRoot: pjRoot[:],
+		},
+	).Return(nil)
+	go func(tt *testing.T) {
+		if err := server.StreamChainHead(&ptypes.Empty{}, mockStream); err != nil {
+			tt.Errorf("Could not call RPC method: %v", err)
+		}
+		<-exitRoutine
+	}(t)
+
+	// Send in a loop to ensure it is delivered (busy wait for the service to subscribe to the state feed).
+	for sent := 0; sent == 0; {
+		sent = server.StateNotifier.StateFeed().Send(&statefeed.Event{
+			Type: statefeed.BlockProcessed,
+			Data: &statefeed.BlockProcessedData{},
+		})
+	}
+	exitRoutine <- true
+}

beacon-chain/rpc/service.go

@@ -226,6 +226,7 @@ func (s *Service) Start() {
 		FinalizationFetcher: s.finalizationFetcher,
 		ChainStartFetcher:   s.chainStartFetcher,
 		CanonicalStateChan:  s.canonicalStateChan,
+		StateNotifier:       s.stateNotifier,
 	}
 	aggregatorServer := &aggregator.Server{
 		BeaconDB:    s.beaconDB,

beacon-chain/rpc/testing/BUILD.bazel

@@ -3,7 +3,10 @@ load("@io_bazel_rules_go//go:def.bzl", "go_library")
 go_library(
     name = "go_default_library",
     testonly = True,
-    srcs = ["validator_service_mock.go"],
+    srcs = [
+        "beacon_chain_service_mock.go",
+        "validator_service_mock.go",
+    ],
     importpath = "github.com/prysmaticlabs/prysm/beacon-chain/rpc/testing",
     visibility = ["//beacon-chain:__subpackages__"],
     deps = [

beacon-chain/rpc/testing/beacon_chain_service_mock.go

@@ -0,0 +1,132 @@
+// Code generated by MockGen. DO NOT EDIT.
+// Source: github.com/prysmaticlabs/ethereumapis/eth/v1alpha1 (interfaces: BeaconChain_StreamChainHeadServer)
+
+// Package testing is a generated GoMock package.
+package testing
+
+import (
+	context "context"
+	gomock "github.com/golang/mock/gomock"
+	v1alpha1 "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
+	metadata "google.golang.org/grpc/metadata"
+	reflect "reflect"
+)
+
+// MockBeaconChain_StreamChainHeadServer is a mock of BeaconChain_StreamChainHeadServer interface
+type MockBeaconChain_StreamChainHeadServer struct {
+	ctrl     *gomock.Controller
+	recorder *MockBeaconChain_StreamChainHeadServerMockRecorder
+}
+
+// MockBeaconChain_StreamChainHeadServerMockRecorder is the mock recorder for MockBeaconChain_StreamChainHeadServer
+type MockBeaconChain_StreamChainHeadServerMockRecorder struct {
+	mock *MockBeaconChain_StreamChainHeadServer
+}
+
+// NewMockBeaconChain_StreamChainHeadServer creates a new mock instance
+func NewMockBeaconChain_StreamChainHeadServer(ctrl *gomock.Controller) *MockBeaconChain_StreamChainHeadServer {
+	mock := &MockBeaconChain_StreamChainHeadServer{ctrl: ctrl}
+	mock.recorder = &MockBeaconChain_StreamChainHeadServerMockRecorder{mock}
+	return mock
+}
+
+// EXPECT returns an object that allows the caller to indicate expected use
+func (m *MockBeaconChain_StreamChainHeadServer) EXPECT() *MockBeaconChain_StreamChainHeadServerMockRecorder {
+	return m.recorder
+}
+
+// Context mocks base method
+func (m *MockBeaconChain_StreamChainHeadServer) Context() context.Context {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Context")
+	ret0, _ := ret[0].(context.Context)
+	return ret0
+}
+
+// Context indicates an expected call of Context
+func (mr *MockBeaconChain_StreamChainHeadServerMockRecorder) Context() *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Context", reflect.TypeOf((*MockBeaconChain_StreamChainHeadServer)(nil).Context))
+}
+
+// RecvMsg mocks base method
+func (m *MockBeaconChain_StreamChainHeadServer) RecvMsg(arg0 interface{}) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "RecvMsg", arg0)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// RecvMsg indicates an expected call of RecvMsg
+func (mr *MockBeaconChain_StreamChainHeadServerMockRecorder) RecvMsg(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "RecvMsg", reflect.TypeOf((*MockBeaconChain_StreamChainHeadServer)(nil).RecvMsg), arg0)
+}
+
+// Send mocks base method
+func (m *MockBeaconChain_StreamChainHeadServer) Send(arg0 *v1alpha1.ChainHead) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "Send", arg0)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// Send indicates an expected call of Send
+func (mr *MockBeaconChain_StreamChainHeadServerMockRecorder) Send(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "Send", reflect.TypeOf((*MockBeaconChain_StreamChainHeadServer)(nil).Send), arg0)
+}
+
+// SendHeader mocks base method
+func (m *MockBeaconChain_StreamChainHeadServer) SendHeader(arg0 metadata.MD) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "SendHeader", arg0)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// SendHeader indicates an expected call of SendHeader
+func (mr *MockBeaconChain_StreamChainHeadServerMockRecorder) SendHeader(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "SendHeader", reflect.TypeOf((*MockBeaconChain_StreamChainHeadServer)(nil).SendHeader), arg0)
+}
+
+// SendMsg mocks base method
+func (m *MockBeaconChain_StreamChainHeadServer) SendMsg(arg0 interface{}) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "SendMsg", arg0)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// SendMsg indicates an expected call of SendMsg
+func (mr *MockBeaconChain_StreamChainHeadServerMockRecorder) SendMsg(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "SendMsg", reflect.TypeOf((*MockBeaconChain_StreamChainHeadServer)(nil).SendMsg), arg0)
+}
+
+// SetHeader mocks base method
+func (m *MockBeaconChain_StreamChainHeadServer) SetHeader(arg0 metadata.MD) error {
+	m.ctrl.T.Helper()
+	ret := m.ctrl.Call(m, "SetHeader", arg0)
+	ret0, _ := ret[0].(error)
+	return ret0
+}
+
+// SetHeader indicates an expected call of SetHeader
+func (mr *MockBeaconChain_StreamChainHeadServerMockRecorder) SetHeader(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "SetHeader", reflect.TypeOf((*MockBeaconChain_StreamChainHeadServer)(nil).SetHeader), arg0)
+}
+
+// SetTrailer mocks base method
+func (m *MockBeaconChain_StreamChainHeadServer) SetTrailer(arg0 metadata.MD) {
+	m.ctrl.T.Helper()
+	m.ctrl.Call(m, "SetTrailer", arg0)
+}
+
+// SetTrailer indicates an expected call of SetTrailer
+func (mr *MockBeaconChain_StreamChainHeadServerMockRecorder) SetTrailer(arg0 interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "SetTrailer", reflect.TypeOf((*MockBeaconChain_StreamChainHeadServer)(nil).SetTrailer), arg0)
+}

endtoend/evaluators/finality.go

@@ -22,7 +22,7 @@ func finalizationOccurs(client eth.BeaconChainClient) error {
 	if err != nil {
 		return errors.Wrap(err, "failed to get chain head")
 	}
-	currentEpoch := chainHead.HeadBlockEpoch
+	currentEpoch := chainHead.HeadEpoch
 	finalizedEpoch := chainHead.FinalizedEpoch
 
 	expectedFinalizedEpoch := currentEpoch - 2

third_party/com_github_prysmaticlabs_ethereumapis-tags.patch

@@ -255,7 +255,7 @@ index 69a148a..1b6ac18 100644
 +    bytes signature = 4 [(gogoproto.moretags) = "ssz-size:\"96\""];
  }
 diff --git a/eth/v1alpha1/beacon_chain.proto b/eth/v1alpha1/beacon_chain.proto
-index 0f490c1..592b169 100644
+index c31fe0f..ee2e2ec 100644
 --- a/eth/v1alpha1/beacon_chain.proto
 +++ b/eth/v1alpha1/beacon_chain.proto
 @@ -15,6 +15,7 @@ syntax = "proto3";
@@ -266,16 +266,29 @@ index 0f490c1..592b169 100644
  import "google/api/annotations.proto";
  import "google/protobuf/empty.proto";
  
-@@ -261,7 +262,7 @@ message BeaconBlockContainer {
- // Information about the head of the beacon chain.
- message ChainHead {
-     // 32 byte merkle tree root of the canonical head block in the beacon node.
--    bytes head_block_root = 1;
-+    bytes head_block_root = 1 [(gogoproto.moretags) = "ssz-size:\"32\""];
+@@ -76,9 +77,9 @@ service BeaconChain {
+         };
+     }
  
-     // Slot of the head block.
-     uint64 head_block_slot = 2;
-@@ -276,7 +277,7 @@ message ChainHead {
+-    // Server-side stream of information about the head of the beacon chain 
+-    // from the view of the beacon chain node. 
+-    // 
++    // Server-side stream of information about the head of the beacon chain
++    // from the view of the beacon chain node.
++    //
+     // This includes the head block slot and root as well as information about
+     // the most recent finalized and justified slots.
+     rpc StreamChainHead(google.protobuf.Empty) returns (stream ChainHead) {
+@@ -278,7 +279,7 @@ message ChainHead {
+     uint64 head_epoch = 2;
+ 
+     // 32 byte merkle tree root of the canonical head block in the beacon node.
+-    bytes head_block_root = 3;
++    bytes head_block_root = 3 [(gogoproto.moretags) = "ssz-size:\"32\""];
+ 
+     // Most recent slot that contains the finalized block.
+     uint64 finalized_slot = 4;
+@@ -287,7 +288,7 @@ message ChainHead {
      uint64 finalized_epoch = 5;
      
      // Most recent 32 byte finalized block root.
@@ -283,8 +296,8 @@ index 0f490c1..592b169 100644
 +    bytes finalized_block_root = 6 [(gogoproto.moretags) = "ssz-size:\"32\""];
  
      // Most recent slot that contains the justified block.
-     uint64 justified_block_slot = 7;
-@@ -285,7 +286,7 @@ message ChainHead {
+     uint64 justified_slot = 7;
+@@ -296,7 +297,7 @@ message ChainHead {
      uint64 justified_epoch = 8;
      
      // Most recent 32 byte justified block root.
@@ -293,7 +306,7 @@ index 0f490c1..592b169 100644
  
      // Most recent slot that contains the previous justified block.
      uint64 previous_justified_slot = 10;
-@@ -294,7 +295,7 @@ message ChainHead {
+@@ -305,7 +306,7 @@ message ChainHead {
      uint64 previous_justified_epoch = 11;
  
      // Previous 32 byte justified block root.
@@ -302,7 +315,7 @@ index 0f490c1..592b169 100644
  }
  
  message ListCommitteesRequest {
-@@ -352,7 +353,7 @@ message ListValidatorBalancesRequest {
+@@ -363,7 +364,7 @@ message ListValidatorBalancesRequest {
  
      // Validator 48 byte BLS public keys to filter validators for the given
      // epoch.
@@ -311,7 +324,7 @@ index 0f490c1..592b169 100644
          
      // Validator indices to filter validators for the given epoch.
      repeated uint64 indices = 4;
-@@ -373,7 +374,7 @@ message ValidatorBalances {
+@@ -384,7 +385,7 @@ message ValidatorBalances {
  
      message Balance {
          // Validator's 48 byte BLS public key.
@@ -320,7 +333,7 @@ index 0f490c1..592b169 100644
  
          // Validator's index in the validator set.
          uint64 index = 2;
-@@ -449,17 +450,17 @@ message ActiveSetChanges {
+@@ -460,17 +461,17 @@ message ActiveSetChanges {
      uint64 epoch = 1;
  
      // 48 byte validator public keys that have been activated in this epoch.
@@ -342,7 +355,7 @@ index 0f490c1..592b169 100644
  }
  
  message ValidatorQueue {
-@@ -469,11 +470,11 @@ message ValidatorQueue {
+@@ -480,11 +481,11 @@ message ValidatorQueue {
  
      // Ordered list of 48 byte public keys awaiting activation. 0th index is the
      // next key to be processed.
@@ -356,7 +369,7 @@ index 0f490c1..592b169 100644
  }
  
  message ListValidatorAssignmentsRequest {
-@@ -485,7 +486,7 @@ message ListValidatorAssignmentsRequest {
+@@ -496,7 +497,7 @@ message ListValidatorAssignmentsRequest {
          bool genesis = 2;
      }
      // 48 byte validator public keys to filter assignments for the given epoch.
@@ -365,7 +378,7 @@ index 0f490c1..592b169 100644
          
      // Validator indicies to filter assignments for the given epoch.
      repeated uint64 indices = 4;
-@@ -520,7 +521,7 @@ message ValidatorAssignments {
+@@ -531,7 +532,7 @@ message ValidatorAssignments {
          uint64 proposer_slot = 4;
  
          // 48 byte BLS public key.

tools/forkchecker/forkchecker.go

@@ -89,8 +89,8 @@ func compareHeads(clients map[string]pb.BeaconChainClient) {
 		log.Fatal(err)
 	}
 
-	log.Infof("Comparing all heads for head slot :%d", head1.HeadBlockSlot)
-	if (head1.HeadBlockSlot+1)%params.BeaconConfig().SlotsPerEpoch == 0 {
+	log.Infof("Comparing all heads for head slot :%d", head1.HeadSlot)
+	if (head1.HeadSlot+1)%params.BeaconConfig().SlotsPerEpoch == 0 {
 		p, err := clients[endpt1].GetValidatorParticipation(context.Background(), &pb.GetValidatorParticipationRequest{})
 		if err != nil {
 			log.Fatal(err)
@@ -108,10 +108,10 @@ func compareHeads(clients map[string]pb.BeaconChainClient) {
 			logHead(endpt1, head1)
 			logHead(endpt2, head2)
 
-			if (head1.HeadBlockSlot+1)%params.BeaconConfig().SlotsPerEpoch == 0 {
+			if (head1.HeadSlot+1)%params.BeaconConfig().SlotsPerEpoch == 0 {
 				p, err := clients[endpt2].GetValidatorParticipation(context.Background(), &pb.GetValidatorParticipationRequest{
 					QueryFilter: &pb.GetValidatorParticipationRequest_Epoch{
-						Epoch: head2.HeadBlockSlot / params.BeaconConfig().SlotsPerEpoch,
+						Epoch: head2.HeadSlot / params.BeaconConfig().SlotsPerEpoch,
 					},
 				})
 				if err != nil {
@@ -126,7 +126,7 @@ func compareHeads(clients map[string]pb.BeaconChainClient) {
 func logHead(endpt string, head *pb.ChainHead) {
 	log.WithFields(
 		logrus.Fields{
-			"HeadSlot":       head.HeadBlockSlot,
+			"HeadSlot":       head.HeadSlot,
 			"HeadRoot":       hex.EncodeToString(head.HeadBlockRoot),
 			"JustifiedEpoch": head.JustifiedEpoch,
 			"JustifiedRoot":  hex.EncodeToString(head.JustifiedBlockRoot),