Reduce size of api/client import graph (#14871)

* relocate DownloadFinalizedData from api to sync

* unexpected go mod changes

---------

Co-authored-by: Kasey Kirkham <kasey@users.noreply.github.com>

api/client/beacon/BUILD.bazel

@@ -3,7 +3,6 @@ load("@prysm//tools/go:def.bzl", "go_library", "go_test")
 go_library(
     name = "go_default_library",
     srcs = [
-        "checkpoint.go",
         "client.go",
         "doc.go",
         "health.go",
@@ -16,28 +15,19 @@ go_library(
         "//api/client/beacon/iface:go_default_library",
         "//api/server:go_default_library",
         "//api/server/structs:go_default_library",
-        "//beacon-chain/core/helpers:go_default_library",
-        "//beacon-chain/state:go_default_library",
-        "//consensus-types/interfaces:go_default_library",
         "//consensus-types/primitives:go_default_library",
         "//encoding/bytesutil:go_default_library",
-        "//encoding/ssz/detect:go_default_library",
-        "//io/file:go_default_library",
         "//network/forks:go_default_library",
         "//proto/prysm/v1alpha1:go_default_library",
-        "//runtime/version:go_default_library",
-        "//time/slots:go_default_library",
         "@com_github_ethereum_go_ethereum//common/hexutil:go_default_library",
         "@com_github_pkg_errors//:go_default_library",
         "@com_github_sirupsen_logrus//:go_default_library",
-        "@org_golang_x_mod//semver:go_default_library",
     ],
 )
 
 go_test(
     name = "go_default_test",
     srcs = [
-        "checkpoint_test.go",
         "client_test.go",
         "health_test.go",
     ],
@@ -45,19 +35,7 @@ go_test(
     deps = [
         "//api/client:go_default_library",
         "//api/client/beacon/testing:go_default_library",
-        "//beacon-chain/state:go_default_library",
-        "//config/params:go_default_library",
-        "//consensus-types/blocks:go_default_library",
-        "//consensus-types/blocks/testing:go_default_library",
-        "//consensus-types/primitives:go_default_library",
-        "//encoding/ssz/detect:go_default_library",
-        "//network/forks:go_default_library",
-        "//proto/prysm/v1alpha1:go_default_library",
-        "//runtime/version:go_default_library",
         "//testing/require:go_default_library",
-        "//testing/util:go_default_library",
-        "//time/slots:go_default_library",
-        "@com_github_pkg_errors//:go_default_library",
         "@org_uber_go_mock//gomock:go_default_library",
     ],
 )

api/client/beacon/checkpoint.go

@@ -1,276 +0,0 @@
-package beacon
-
-import (
-	"context"
-	"fmt"
-	"path"
-
-	"github.com/ethereum/go-ethereum/common/hexutil"
-	"github.com/pkg/errors"
-	base "github.com/prysmaticlabs/prysm/v5/api/client"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/core/helpers"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/interfaces"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/bytesutil"
-	"github.com/prysmaticlabs/prysm/v5/encoding/ssz/detect"
-	"github.com/prysmaticlabs/prysm/v5/io/file"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
-	"github.com/sirupsen/logrus"
-	"golang.org/x/mod/semver"
-)
-
-var errCheckpointBlockMismatch = errors.New("mismatch between checkpoint sync state and block")
-
-// OriginData represents the BeaconState and ReadOnlySignedBeaconBlock necessary to start an empty Beacon Node
-// using Checkpoint Sync.
-type OriginData struct {
-	sb []byte
-	bb []byte
-	st state.BeaconState
-	b  interfaces.ReadOnlySignedBeaconBlock
-	vu *detect.VersionedUnmarshaler
-	br [32]byte
-	sr [32]byte
-}
-
-// SaveBlock saves the downloaded block to a unique file in the given path.
-// For readability and collision avoidance, the file name includes: type, config name, slot and root
-func (o *OriginData) SaveBlock(dir string) (string, error) {
-	blockPath := path.Join(dir, fname("block", o.vu, o.b.Block().Slot(), o.br))
-	return blockPath, file.WriteFile(blockPath, o.BlockBytes())
-}
-
-// SaveState saves the downloaded state to a unique file in the given path.
-// For readability and collision avoidance, the file name includes: type, config name, slot and root
-func (o *OriginData) SaveState(dir string) (string, error) {
-	statePath := path.Join(dir, fname("state", o.vu, o.st.Slot(), o.sr))
-	return statePath, file.WriteFile(statePath, o.StateBytes())
-}
-
-// StateBytes returns the ssz-encoded bytes of the downloaded BeaconState value.
-func (o *OriginData) StateBytes() []byte {
-	return o.sb
-}
-
-// BlockBytes returns the ssz-encoded bytes of the downloaded ReadOnlySignedBeaconBlock value.
-func (o *OriginData) BlockBytes() []byte {
-	return o.bb
-}
-
-func fname(prefix string, vu *detect.VersionedUnmarshaler, slot primitives.Slot, root [32]byte) string {
-	return fmt.Sprintf("%s_%s_%s_%d-%#x.ssz", prefix, vu.Config.ConfigName, version.String(vu.Fork), slot, root)
-}
-
-// DownloadFinalizedData downloads the most recently finalized state, and the block most recently applied to that state.
-// This pair can be used to initialize a new beacon node via checkpoint sync.
-func DownloadFinalizedData(ctx context.Context, client *Client) (*OriginData, error) {
-	sb, err := client.GetState(ctx, IdFinalized)
-	if err != nil {
-		return nil, err
-	}
-	vu, err := detect.FromState(sb)
-	if err != nil {
-		return nil, errors.Wrap(err, "error detecting chain config for finalized state")
-	}
-
-	log.WithFields(logrus.Fields{
-		"name": vu.Config.ConfigName,
-		"fork": version.String(vu.Fork),
-	}).Info("Detected supported config in remote finalized state")
-
-	s, err := vu.UnmarshalBeaconState(sb)
-	if err != nil {
-		return nil, errors.Wrap(err, "error unmarshaling finalized state to correct version")
-	}
-
-	slot := s.LatestBlockHeader().Slot
-	bb, err := client.GetBlock(ctx, IdFromSlot(slot))
-	if err != nil {
-		return nil, errors.Wrapf(err, "error requesting block by slot = %d", slot)
-	}
-	b, err := vu.UnmarshalBeaconBlock(bb)
-	if err != nil {
-		return nil, errors.Wrap(err, "unable to unmarshal block to a supported type using the detected fork schedule")
-	}
-	br, err := b.Block().HashTreeRoot()
-	if err != nil {
-		return nil, errors.Wrap(err, "error computing hash_tree_root of retrieved block")
-	}
-	bodyRoot, err := b.Block().Body().HashTreeRoot()
-	if err != nil {
-		return nil, errors.Wrap(err, "error computing hash_tree_root of retrieved block body")
-	}
-
-	sbr := bytesutil.ToBytes32(s.LatestBlockHeader().BodyRoot)
-	if sbr != bodyRoot {
-		return nil, errors.Wrapf(errCheckpointBlockMismatch, "state body root = %#x, block body root = %#x", sbr, bodyRoot)
-	}
-	sr, err := s.HashTreeRoot(ctx)
-	if err != nil {
-		return nil, errors.Wrapf(err, "failed to compute htr for finalized state at slot=%d", s.Slot())
-	}
-
-	log.
-		WithField("blockSlot", b.Block().Slot()).
-		WithField("stateSlot", s.Slot()).
-		WithField("stateRoot", hexutil.Encode(sr[:])).
-		WithField("blockRoot", hexutil.Encode(br[:])).
-		Info("Downloaded checkpoint sync state and block.")
-	return &OriginData{
-		st: s,
-		b:  b,
-		sb: sb,
-		bb: bb,
-		vu: vu,
-		br: br,
-		sr: sr,
-	}, nil
-}
-
-// WeakSubjectivityData represents the state root, block root and epoch of the BeaconState + ReadOnlySignedBeaconBlock
-// that falls at the beginning of the current weak subjectivity period. These values can be used to construct
-// a weak subjectivity checkpoint beacon node flag to be used for validation.
-type WeakSubjectivityData struct {
-	BlockRoot [32]byte
-	StateRoot [32]byte
-	Epoch     primitives.Epoch
-}
-
-// CheckpointString returns the standard string representation of a Checkpoint.
-// The format is a hex-encoded block root, followed by the epoch of the block, separated by a colon. For example:
-// "0x1c35540cac127315fabb6bf29181f2ae0de1a3fc909d2e76ba771e61312cc49a:74888"
-func (wsd *WeakSubjectivityData) CheckpointString() string {
-	return fmt.Sprintf("%#x:%d", wsd.BlockRoot, wsd.Epoch)
-}
-
-// ComputeWeakSubjectivityCheckpoint attempts to use the prysm weak_subjectivity api
-// to obtain the current weak_subjectivity checkpoint.
-// For non-prysm nodes, the same computation will be performed with extra steps,
-// using the head state downloaded from the beacon node api.
-func ComputeWeakSubjectivityCheckpoint(ctx context.Context, client *Client) (*WeakSubjectivityData, error) {
-	ws, err := client.GetWeakSubjectivity(ctx)
-	if err != nil {
-		// a 404/405 is expected if querying an endpoint that doesn't support the weak subjectivity checkpoint api
-		if !errors.Is(err, base.ErrNotOK) {
-			return nil, errors.Wrap(err, "unexpected API response for prysm-only weak subjectivity checkpoint API")
-		}
-		// fall back to vanilla Beacon Node API method
-		return computeBackwardsCompatible(ctx, client)
-	}
-	log.Printf("server weak subjectivity checkpoint response - epoch=%d, block_root=%#x, state_root=%#x", ws.Epoch, ws.BlockRoot, ws.StateRoot)
-	return ws, nil
-}
-
-const (
-	prysmMinimumVersion     = "v2.0.7"
-	prysmImplementationName = "Prysm"
-)
-
-// errUnsupportedPrysmCheckpointVersion indicates remote beacon node can't be used for checkpoint retrieval.
-var errUnsupportedPrysmCheckpointVersion = errors.New("node does not meet minimum version requirements for checkpoint retrieval")
-
-// for older endpoints or clients that do not support the weak_subjectivity api method
-// we gather the necessary data for a checkpoint sync by:
-// - inspecting the remote server's head state and computing the weak subjectivity epoch locally
-// - requesting the state at the first slot of the epoch
-// - using hash_tree_root(state.latest_block_header) to compute the block the state integrates
-// - requesting that block by its root
-func computeBackwardsCompatible(ctx context.Context, client *Client) (*WeakSubjectivityData, error) {
-	log.Print("falling back to generic checkpoint derivation, weak_subjectivity API not supported by server")
-	nv, err := client.GetNodeVersion(ctx)
-	if err != nil {
-		return nil, errors.Wrap(err, "unable to proceed with fallback method without confirming node version")
-	}
-	if nv.implementation == prysmImplementationName && semver.Compare(nv.semver, prysmMinimumVersion) < 0 {
-		return nil, errors.Wrapf(errUnsupportedPrysmCheckpointVersion, "%s < minimum (%s)", nv.semver, prysmMinimumVersion)
-	}
-	epoch, err := getWeakSubjectivityEpochFromHead(ctx, client)
-	if err != nil {
-		return nil, errors.Wrap(err, "error computing weak subjectivity epoch via head state inspection")
-	}
-
-	// use first slot of the epoch for the state slot
-	slot, err := slots.EpochStart(epoch)
-	if err != nil {
-		return nil, errors.Wrapf(err, "error computing first slot of epoch=%d", epoch)
-	}
-
-	log.Printf("requesting checkpoint state at slot %d", slot)
-	// get the state at the first slot of the epoch
-	sb, err := client.GetState(ctx, IdFromSlot(slot))
-	if err != nil {
-		return nil, errors.Wrapf(err, "failed to request state by slot from api, slot=%d", slot)
-	}
-
-	// ConfigFork is used to unmarshal the BeaconState so we can read the block root in latest_block_header
-	vu, err := detect.FromState(sb)
-	if err != nil {
-		return nil, errors.Wrap(err, "error detecting chain config for beacon state")
-	}
-	log.Printf("detected supported config in checkpoint state, name=%s, fork=%s", vu.Config.ConfigName, version.String(vu.Fork))
-
-	s, err := vu.UnmarshalBeaconState(sb)
-	if err != nil {
-		return nil, errors.Wrap(err, "error using detected config fork to unmarshal state bytes")
-	}
-
-	// compute state and block roots
-	sr, err := s.HashTreeRoot(ctx)
-	if err != nil {
-		return nil, errors.Wrap(err, "error computing hash_tree_root of state")
-	}
-
-	h := s.LatestBlockHeader()
-	h.StateRoot = sr[:]
-	br, err := h.HashTreeRoot()
-	if err != nil {
-		return nil, errors.Wrap(err, "error while computing block root using state data")
-	}
-
-	bb, err := client.GetBlock(ctx, IdFromRoot(br))
-	if err != nil {
-		return nil, errors.Wrapf(err, "error requesting block by root = %d", br)
-	}
-	b, err := vu.UnmarshalBeaconBlock(bb)
-	if err != nil {
-		return nil, errors.Wrap(err, "unable to unmarshal block to a supported type using the detected fork schedule")
-	}
-	br, err = b.Block().HashTreeRoot()
-	if err != nil {
-		return nil, errors.Wrap(err, "error computing hash_tree_root for block obtained via root")
-	}
-
-	return &WeakSubjectivityData{
-		Epoch:     epoch,
-		BlockRoot: br,
-		StateRoot: sr,
-	}, nil
-}
-
-// this method downloads the head state, which can be used to find the correct chain config
-// and use prysm's helper methods to compute the latest weak subjectivity epoch.
-func getWeakSubjectivityEpochFromHead(ctx context.Context, client *Client) (primitives.Epoch, error) {
-	headBytes, err := client.GetState(ctx, IdHead)
-	if err != nil {
-		return 0, err
-	}
-	vu, err := detect.FromState(headBytes)
-	if err != nil {
-		return 0, errors.Wrap(err, "error detecting chain config for beacon state")
-	}
-	log.Printf("detected supported config in remote head state, name=%s, fork=%s", vu.Config.ConfigName, version.String(vu.Fork))
-	headState, err := vu.UnmarshalBeaconState(headBytes)
-	if err != nil {
-		return 0, errors.Wrap(err, "error unmarshaling state to correct version")
-	}
-
-	epoch, err := helpers.LatestWeakSubjectivityEpoch(ctx, headState, vu.Config)
-	if err != nil {
-		return 0, errors.Wrap(err, "error computing the weak subjectivity epoch from head state")
-	}
-
-	log.Printf("(computed client-side) weak subjectivity epoch = %d", epoch)
-	return epoch, nil
-}

api/client/beacon/checkpoint_test.go

@@ -1,481 +0,0 @@
-package beacon
-
-import (
-	"bytes"
-	"context"
-	"encoding/json"
-	"fmt"
-	"io"
-	"net/http"
-	"testing"
-
-	"github.com/pkg/errors"
-	"github.com/prysmaticlabs/prysm/v5/api/client"
-	"github.com/prysmaticlabs/prysm/v5/beacon-chain/state"
-	"github.com/prysmaticlabs/prysm/v5/config/params"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/blocks"
-	blocktest "github.com/prysmaticlabs/prysm/v5/consensus-types/blocks/testing"
-	"github.com/prysmaticlabs/prysm/v5/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v5/encoding/ssz/detect"
-	"github.com/prysmaticlabs/prysm/v5/network/forks"
-	ethpb "github.com/prysmaticlabs/prysm/v5/proto/prysm/v1alpha1"
-	"github.com/prysmaticlabs/prysm/v5/runtime/version"
-	"github.com/prysmaticlabs/prysm/v5/testing/require"
-	"github.com/prysmaticlabs/prysm/v5/testing/util"
-	"github.com/prysmaticlabs/prysm/v5/time/slots"
-)
-
-type testRT struct {
-	rt func(*http.Request) (*http.Response, error)
-}
-
-func (rt *testRT) RoundTrip(req *http.Request) (*http.Response, error) {
-	if rt.rt != nil {
-		return rt.rt(req)
-	}
-	return nil, errors.New("RoundTripper not implemented")
-}
-
-var _ http.RoundTripper = &testRT{}
-
-func marshalToEnvelope(val interface{}) ([]byte, error) {
-	raw, err := json.Marshal(val)
-	if err != nil {
-		return nil, errors.Wrap(err, "error marshaling value to place in data envelope")
-	}
-	env := struct {
-		Data json.RawMessage `json:"data"`
-	}{
-		Data: raw,
-	}
-	return json.Marshal(env)
-}
-
-func TestMarshalToEnvelope(t *testing.T) {
-	d := struct {
-		Version string `json:"version"`
-	}{
-		Version: "Prysm/v2.0.5 (linux amd64)",
-	}
-	encoded, err := marshalToEnvelope(d)
-	require.NoError(t, err)
-	expected := `{"data":{"version":"Prysm/v2.0.5 (linux amd64)"}}`
-	require.Equal(t, expected, string(encoded))
-}
-
-func TestFallbackVersionCheck(t *testing.T) {
-	trans := &testRT{rt: func(req *http.Request) (*http.Response, error) {
-		res := &http.Response{Request: req}
-		switch req.URL.Path {
-		case getNodeVersionPath:
-			res.StatusCode = http.StatusOK
-			b := bytes.NewBuffer(nil)
-			d := struct {
-				Version string `json:"version"`
-			}{
-				Version: "Prysm/v2.0.5 (linux amd64)",
-			}
-			encoded, err := marshalToEnvelope(d)
-			require.NoError(t, err)
-			b.Write(encoded)
-			res.Body = io.NopCloser(b)
-		case getWeakSubjectivityPath:
-			res.StatusCode = http.StatusNotFound
-		}
-		return res, nil
-	}}
-
-	c, err := NewClient("http://localhost:3500", client.WithRoundTripper(trans))
-	require.NoError(t, err)
-	ctx := context.Background()
-	_, err = ComputeWeakSubjectivityCheckpoint(ctx, c)
-	require.ErrorIs(t, err, errUnsupportedPrysmCheckpointVersion)
-}
-
-func TestFname(t *testing.T) {
-	vu := &detect.VersionedUnmarshaler{
-		Config: params.MainnetConfig(),
-		Fork:   version.Phase0,
-	}
-	slot := primitives.Slot(23)
-	prefix := "block"
-	var root [32]byte
-	copy(root[:], []byte{0x23, 0x23, 0x23})
-	expected := "block_mainnet_phase0_23-0x2323230000000000000000000000000000000000000000000000000000000000.ssz"
-	actual := fname(prefix, vu, slot, root)
-	require.Equal(t, expected, actual)
-
-	vu.Config = params.MinimalSpecConfig()
-	vu.Fork = version.Altair
-	slot = 17
-	prefix = "state"
-	copy(root[29:], []byte{0x17, 0x17, 0x17})
-	expected = "state_minimal_altair_17-0x2323230000000000000000000000000000000000000000000000000000171717.ssz"
-	actual = fname(prefix, vu, slot, root)
-	require.Equal(t, expected, actual)
-}
-
-func TestDownloadWeakSubjectivityCheckpoint(t *testing.T) {
-	ctx := context.Background()
-	cfg := params.MainnetConfig().Copy()
-
-	epoch := cfg.AltairForkEpoch - 1
-	// set up checkpoint state, using the epoch that will be computed as the ws checkpoint state based on the head state
-	wSlot, err := slots.EpochStart(epoch)
-	require.NoError(t, err)
-	wst, err := util.NewBeaconState()
-	require.NoError(t, err)
-	fork, err := forkForEpoch(cfg, epoch)
-	require.NoError(t, err)
-	require.NoError(t, wst.SetFork(fork))
-
-	// set up checkpoint block
-	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
-	require.NoError(t, err)
-	b, err = blocktest.SetBlockParentRoot(b, cfg.ZeroHash)
-	require.NoError(t, err)
-	b, err = blocktest.SetBlockSlot(b, wSlot)
-	require.NoError(t, err)
-	b, err = blocktest.SetProposerIndex(b, 0)
-	require.NoError(t, err)
-
-	// set up state header pointing at checkpoint block - this is how the block is downloaded by root
-	header, err := b.Header()
-	require.NoError(t, err)
-	require.NoError(t, wst.SetLatestBlockHeader(header.Header))
-
-	// order of operations can be confusing here:
-	// - when computing the state root, make sure block header is complete, EXCEPT the state root should be zero-value
-	// - before computing the block root (to match the request route), the block should include the state root
-	//   *computed from the state with a header that does not have a state root set yet*
-	wRoot, err := wst.HashTreeRoot(ctx)
-	require.NoError(t, err)
-
-	b, err = blocktest.SetBlockStateRoot(b, wRoot)
-	require.NoError(t, err)
-	serBlock, err := b.MarshalSSZ()
-	require.NoError(t, err)
-	bRoot, err := b.Block().HashTreeRoot()
-	require.NoError(t, err)
-
-	wsSerialized, err := wst.MarshalSSZ()
-	require.NoError(t, err)
-	expectedWSD := WeakSubjectivityData{
-		BlockRoot: bRoot,
-		StateRoot: wRoot,
-		Epoch:     epoch,
-	}
-
-	trans := &testRT{rt: func(req *http.Request) (*http.Response, error) {
-		res := &http.Response{Request: req}
-		switch req.URL.Path {
-		case getWeakSubjectivityPath:
-			res.StatusCode = http.StatusOK
-			cp := struct {
-				Epoch string `json:"epoch"`
-				Root  string `json:"root"`
-			}{
-				Epoch: fmt.Sprintf("%d", slots.ToEpoch(b.Block().Slot())),
-				Root:  fmt.Sprintf("%#x", bRoot),
-			}
-			wsr := struct {
-				Checkpoint interface{} `json:"ws_checkpoint"`
-				StateRoot  string      `json:"state_root"`
-			}{
-				Checkpoint: cp,
-				StateRoot:  fmt.Sprintf("%#x", wRoot),
-			}
-			rb, err := marshalToEnvelope(wsr)
-			require.NoError(t, err)
-			res.Body = io.NopCloser(bytes.NewBuffer(rb))
-		case renderGetStatePath(IdFromSlot(wSlot)):
-			res.StatusCode = http.StatusOK
-			res.Body = io.NopCloser(bytes.NewBuffer(wsSerialized))
-		case renderGetBlockPath(IdFromRoot(bRoot)):
-			res.StatusCode = http.StatusOK
-			res.Body = io.NopCloser(bytes.NewBuffer(serBlock))
-		}
-
-		return res, nil
-	}}
-
-	c, err := NewClient("http://localhost:3500", client.WithRoundTripper(trans))
-	require.NoError(t, err)
-
-	wsd, err := ComputeWeakSubjectivityCheckpoint(ctx, c)
-	require.NoError(t, err)
-	require.Equal(t, expectedWSD.Epoch, wsd.Epoch)
-	require.Equal(t, expectedWSD.StateRoot, wsd.StateRoot)
-	require.Equal(t, expectedWSD.BlockRoot, wsd.BlockRoot)
-}
-
-// runs computeBackwardsCompatible directly
-// and via ComputeWeakSubjectivityCheckpoint with a round tripper that triggers the backwards compatible code path
-func TestDownloadBackwardsCompatibleCombined(t *testing.T) {
-	ctx := context.Background()
-	cfg := params.MainnetConfig()
-
-	st, expectedEpoch := defaultTestHeadState(t, cfg)
-	serialized, err := st.MarshalSSZ()
-	require.NoError(t, err)
-
-	// set up checkpoint state, using the epoch that will be computed as the ws checkpoint state based on the head state
-	wSlot, err := slots.EpochStart(expectedEpoch)
-	require.NoError(t, err)
-	wst, err := util.NewBeaconState()
-	require.NoError(t, err)
-	fork, err := forkForEpoch(cfg, cfg.GenesisEpoch)
-	require.NoError(t, err)
-	require.NoError(t, wst.SetFork(fork))
-
-	// set up checkpoint block
-	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
-	require.NoError(t, err)
-	b, err = blocktest.SetBlockParentRoot(b, cfg.ZeroHash)
-	require.NoError(t, err)
-	b, err = blocktest.SetBlockSlot(b, wSlot)
-	require.NoError(t, err)
-	b, err = blocktest.SetProposerIndex(b, 0)
-	require.NoError(t, err)
-
-	// set up state header pointing at checkpoint block - this is how the block is downloaded by root
-	header, err := b.Header()
-	require.NoError(t, err)
-	require.NoError(t, wst.SetLatestBlockHeader(header.Header))
-
-	// order of operations can be confusing here:
-	// - when computing the state root, make sure block header is complete, EXCEPT the state root should be zero-value
-	// - before computing the block root (to match the request route), the block should include the state root
-	//   *computed from the state with a header that does not have a state root set yet*
-	wRoot, err := wst.HashTreeRoot(ctx)
-	require.NoError(t, err)
-
-	b, err = blocktest.SetBlockStateRoot(b, wRoot)
-	require.NoError(t, err)
-	serBlock, err := b.MarshalSSZ()
-	require.NoError(t, err)
-	bRoot, err := b.Block().HashTreeRoot()
-	require.NoError(t, err)
-
-	wsSerialized, err := wst.MarshalSSZ()
-	require.NoError(t, err)
-
-	trans := &testRT{rt: func(req *http.Request) (*http.Response, error) {
-		res := &http.Response{Request: req}
-		switch req.URL.Path {
-		case getNodeVersionPath:
-			res.StatusCode = http.StatusOK
-			b := bytes.NewBuffer(nil)
-			d := struct {
-				Version string `json:"version"`
-			}{
-				Version: "Lighthouse/v0.1.5 (Linux x86_64)",
-			}
-			encoded, err := marshalToEnvelope(d)
-			require.NoError(t, err)
-			b.Write(encoded)
-			res.Body = io.NopCloser(b)
-		case getWeakSubjectivityPath:
-			res.StatusCode = http.StatusNotFound
-		case renderGetStatePath(IdHead):
-			res.StatusCode = http.StatusOK
-			res.Body = io.NopCloser(bytes.NewBuffer(serialized))
-		case renderGetStatePath(IdFromSlot(wSlot)):
-			res.StatusCode = http.StatusOK
-			res.Body = io.NopCloser(bytes.NewBuffer(wsSerialized))
-		case renderGetBlockPath(IdFromRoot(bRoot)):
-			res.StatusCode = http.StatusOK
-			res.Body = io.NopCloser(bytes.NewBuffer(serBlock))
-		}
-
-		return res, nil
-	}}
-
-	c, err := NewClient("http://localhost:3500", client.WithRoundTripper(trans))
-	require.NoError(t, err)
-
-	wsPub, err := ComputeWeakSubjectivityCheckpoint(ctx, c)
-	require.NoError(t, err)
-
-	wsPriv, err := computeBackwardsCompatible(ctx, c)
-	require.NoError(t, err)
-	require.DeepEqual(t, wsPriv, wsPub)
-}
-
-func TestGetWeakSubjectivityEpochFromHead(t *testing.T) {
-	st, expectedEpoch := defaultTestHeadState(t, params.MainnetConfig())
-	serialized, err := st.MarshalSSZ()
-	require.NoError(t, err)
-	trans := &testRT{rt: func(req *http.Request) (*http.Response, error) {
-		res := &http.Response{Request: req}
-		if req.URL.Path == renderGetStatePath(IdHead) {
-			res.StatusCode = http.StatusOK
-			res.Body = io.NopCloser(bytes.NewBuffer(serialized))
-		}
-		return res, nil
-	}}
-	c, err := NewClient("http://localhost:3500", client.WithRoundTripper(trans))
-	require.NoError(t, err)
-	actualEpoch, err := getWeakSubjectivityEpochFromHead(context.Background(), c)
-	require.NoError(t, err)
-	require.Equal(t, expectedEpoch, actualEpoch)
-}
-
-func forkForEpoch(cfg *params.BeaconChainConfig, epoch primitives.Epoch) (*ethpb.Fork, error) {
-	os := forks.NewOrderedSchedule(cfg)
-	currentVersion, err := os.VersionForEpoch(epoch)
-	if err != nil {
-		return nil, err
-	}
-	prevVersion, err := os.Previous(currentVersion)
-	if err != nil {
-		if !errors.Is(err, forks.ErrNoPreviousVersion) {
-			return nil, err
-		}
-		// use same version for both in the case of genesis
-		prevVersion = currentVersion
-	}
-	forkEpoch := cfg.ForkVersionSchedule[currentVersion]
-	return &ethpb.Fork{
-		PreviousVersion: prevVersion[:],
-		CurrentVersion:  currentVersion[:],
-		Epoch:           forkEpoch,
-	}, nil
-}
-
-func defaultTestHeadState(t *testing.T, cfg *params.BeaconChainConfig) (state.BeaconState, primitives.Epoch) {
-	st, err := util.NewBeaconStateAltair()
-	require.NoError(t, err)
-
-	fork, err := forkForEpoch(cfg, cfg.AltairForkEpoch)
-	require.NoError(t, err)
-	require.NoError(t, st.SetFork(fork))
-
-	slot, err := slots.EpochStart(cfg.AltairForkEpoch)
-	require.NoError(t, err)
-	require.NoError(t, st.SetSlot(slot))
-
-	var validatorCount, avgBalance uint64 = 100, 35
-	require.NoError(t, populateValidators(cfg, st, validatorCount, avgBalance))
-	require.NoError(t, st.SetFinalizedCheckpoint(&ethpb.Checkpoint{
-		Epoch: fork.Epoch - 10,
-		Root:  make([]byte, 32),
-	}))
-	// to see the math for this, look at helpers.LatestWeakSubjectivityEpoch
-	// and for the values use mainnet config values, the validatorCount and avgBalance above, and altair fork epoch
-	expectedEpoch := slots.ToEpoch(st.Slot()) - 224
-	return st, expectedEpoch
-}
-
-// TODO(10429): refactor beacon state options in testing/util to take a state.BeaconState so this can become an option
-func populateValidators(cfg *params.BeaconChainConfig, st state.BeaconState, valCount, avgBalance uint64) error {
-	validators := make([]*ethpb.Validator, valCount)
-	balances := make([]uint64, len(validators))
-	for i := uint64(0); i < valCount; i++ {
-		validators[i] = &ethpb.Validator{
-			PublicKey:             make([]byte, cfg.BLSPubkeyLength),
-			WithdrawalCredentials: make([]byte, 32),
-			EffectiveBalance:      avgBalance * 1e9,
-			ExitEpoch:             cfg.FarFutureEpoch,
-		}
-		balances[i] = validators[i].EffectiveBalance
-	}
-
-	if err := st.SetValidators(validators); err != nil {
-		return err
-	}
-	return st.SetBalances(balances)
-}
-
-func TestDownloadFinalizedData(t *testing.T) {
-	ctx := context.Background()
-	cfg := params.MainnetConfig().Copy()
-
-	// avoid the altair zone because genesis tests are easier to set up
-	epoch := cfg.AltairForkEpoch - 1
-	// set up checkpoint state, using the epoch that will be computed as the ws checkpoint state based on the head state
-	slot, err := slots.EpochStart(epoch)
-	require.NoError(t, err)
-	st, err := util.NewBeaconState()
-	require.NoError(t, err)
-	fork, err := forkForEpoch(cfg, epoch)
-	require.NoError(t, err)
-	require.NoError(t, st.SetFork(fork))
-	require.NoError(t, st.SetSlot(slot))
-
-	// set up checkpoint block
-	b, err := blocks.NewSignedBeaconBlock(util.NewBeaconBlock())
-	require.NoError(t, err)
-	b, err = blocktest.SetBlockParentRoot(b, cfg.ZeroHash)
-	require.NoError(t, err)
-	b, err = blocktest.SetBlockSlot(b, slot)
-	require.NoError(t, err)
-	b, err = blocktest.SetProposerIndex(b, 0)
-	require.NoError(t, err)
-
-	// set up state header pointing at checkpoint block - this is how the block is downloaded by root
-	header, err := b.Header()
-	require.NoError(t, err)
-	require.NoError(t, st.SetLatestBlockHeader(header.Header))
-
-	// order of operations can be confusing here:
-	// - when computing the state root, make sure block header is complete, EXCEPT the state root should be zero-value
-	// - before computing the block root (to match the request route), the block should include the state root
-	//   *computed from the state with a header that does not have a state root set yet*
-	sr, err := st.HashTreeRoot(ctx)
-	require.NoError(t, err)
-
-	b, err = blocktest.SetBlockStateRoot(b, sr)
-	require.NoError(t, err)
-	mb, err := b.MarshalSSZ()
-	require.NoError(t, err)
-	br, err := b.Block().HashTreeRoot()
-	require.NoError(t, err)
-
-	ms, err := st.MarshalSSZ()
-	require.NoError(t, err)
-
-	trans := &testRT{rt: func(req *http.Request) (*http.Response, error) {
-		res := &http.Response{Request: req}
-		switch req.URL.Path {
-		case renderGetStatePath(IdFinalized):
-			res.StatusCode = http.StatusOK
-			res.Body = io.NopCloser(bytes.NewBuffer(ms))
-		case renderGetBlockPath(IdFromSlot(b.Block().Slot())):
-			res.StatusCode = http.StatusOK
-			res.Body = io.NopCloser(bytes.NewBuffer(mb))
-		default:
-			res.StatusCode = http.StatusInternalServerError
-			res.Body = io.NopCloser(bytes.NewBufferString(""))
-		}
-
-		return res, nil
-	}}
-	c, err := NewClient("http://localhost:3500", client.WithRoundTripper(trans))
-	require.NoError(t, err)
-	// sanity check before we go through checkpoint
-	// make sure we can download the state and unmarshal it with the VersionedUnmarshaler
-	sb, err := c.GetState(ctx, IdFinalized)
-	require.NoError(t, err)
-	require.Equal(t, true, bytes.Equal(sb, ms))
-	vu, err := detect.FromState(sb)
-	require.NoError(t, err)
-	us, err := vu.UnmarshalBeaconState(sb)
-	require.NoError(t, err)
-	ushtr, err := us.HashTreeRoot(ctx)
-	require.NoError(t, err)
-	require.Equal(t, sr, ushtr)
-
-	expected := &OriginData{
-		sb: ms,
-		bb: mb,
-		br: br,
-		sr: sr,
-	}
-	od, err := DownloadFinalizedData(ctx, c)
-	require.NoError(t, err)
-	require.Equal(t, true, bytes.Equal(expected.sb, od.sb))
-	require.Equal(t, true, bytes.Equal(expected.bb, od.bb))
-	require.Equal(t, expected.br, od.br)
-	require.Equal(t, expected.sr, od.sr)
-}

api/client/beacon/client.go

@@ -29,12 +29,13 @@ const (
 	getSignedBlockPath       = "/eth/v2/beacon/blocks"
 	getBlockRootPath         = "/eth/v1/beacon/blocks/{{.Id}}/root"
 	getForkForStatePath      = "/eth/v1/beacon/states/{{.Id}}/fork"
-	getWeakSubjectivityPath  = "/prysm/v1/beacon/weak_subjectivity"
 	getForkSchedulePath      = "/eth/v1/config/fork_schedule"
 	getConfigSpecPath        = "/eth/v1/config/spec"
 	getStatePath             = "/eth/v2/debug/beacon/states"
-	getNodeVersionPath       = "/eth/v1/node/version"
 	changeBLStoExecutionPath = "/eth/v1/beacon/pool/bls_to_execution_changes"
+
+	GetNodeVersionPath      = "/eth/v1/node/version"
+	GetWeakSubjectivityPath = "/prysm/v1/beacon/weak_subjectivity"
 )
 
 // StateOrBlockId represents the block_id / state_id parameters that several of the Eth Beacon API methods accept.
@@ -80,7 +81,8 @@ func idTemplate(ts string) func(StateOrBlockId) string {
 	return f
 }
 
-func renderGetBlockPath(id StateOrBlockId) string {
+// RenderGetBlockPath formats a block id into a path for the GetBlock API endpoint.
+func RenderGetBlockPath(id StateOrBlockId) string {
 	return path.Join(getSignedBlockPath, string(id))
 }
 
@@ -104,7 +106,7 @@ func NewClient(host string, opts ...client.ClientOpt) (*Client, error) {
 // for the named identifiers.
 // The return value contains the ssz-encoded bytes.
 func (c *Client) GetBlock(ctx context.Context, blockId StateOrBlockId) ([]byte, error) {
-	blockPath := renderGetBlockPath(blockId)
+	blockPath := RenderGetBlockPath(blockId)
 	b, err := c.Get(ctx, blockPath, client.WithSSZEncoding())
 	if err != nil {
 		return nil, errors.Wrapf(err, "error requesting state by id = %s", blockId)
@@ -195,6 +197,10 @@ type NodeVersion struct {
 	systemInfo     string
 }
 
+func (nv *NodeVersion) SetImplementation(impl string) {
+	nv.implementation = impl
+}
+
 var versionRE = regexp.MustCompile(`^(\w+)/(v\d+\.\d+\.\d+[-a-zA-Z0-9]*)\s*/?(.*)$`)
 
 func parseNodeVersion(v string) (*NodeVersion, error) {
@@ -212,7 +218,7 @@ func parseNodeVersion(v string) (*NodeVersion, error) {
 // GetNodeVersion requests that the beacon node identify information about its implementation in a format
 // similar to a HTTP User-Agent field. ex: Lighthouse/v0.1.5 (Linux x86_64)
 func (c *Client) GetNodeVersion(ctx context.Context) (*NodeVersion, error) {
-	b, err := c.Get(ctx, getNodeVersionPath)
+	b, err := c.Get(ctx, GetNodeVersionPath)
 	if err != nil {
 		return nil, errors.Wrap(err, "error requesting node version")
 	}
@@ -228,7 +234,8 @@ func (c *Client) GetNodeVersion(ctx context.Context) (*NodeVersion, error) {
 	return parseNodeVersion(d.Data.Version)
 }
 
-func renderGetStatePath(id StateOrBlockId) string {
+// RenderGetStatePath formats a state id into a path for the GetState API endpoint.
+func RenderGetStatePath(id StateOrBlockId) string {
 	return path.Join(getStatePath, string(id))
 }
 
@@ -246,13 +253,29 @@ func (c *Client) GetState(ctx context.Context, stateId StateOrBlockId) ([]byte,
 	return b, nil
 }
 
+// WeakSubjectivityData represents the state root, block root and epoch of the BeaconState + ReadOnlySignedBeaconBlock
+// that falls at the beginning of the current weak subjectivity period. These values can be used to construct
+// a weak subjectivity checkpoint beacon node flag to be used for validation.
+type WeakSubjectivityData struct {
+	BlockRoot [32]byte
+	StateRoot [32]byte
+	Epoch     primitives.Epoch
+}
+
+// CheckpointString returns the standard string representation of a Checkpoint.
+// The format is a hex-encoded block root, followed by the epoch of the block, separated by a colon. For example:
+// "0x1c35540cac127315fabb6bf29181f2ae0de1a3fc909d2e76ba771e61312cc49a:74888"
+func (wsd *WeakSubjectivityData) CheckpointString() string {
+	return fmt.Sprintf("%#x:%d", wsd.BlockRoot, wsd.Epoch)
+}
+
 // GetWeakSubjectivity calls a proposed API endpoint that is unique to prysm
 // This api method does the following:
 // - computes weak subjectivity epoch
 // - finds the highest non-skipped block preceding the epoch
 // - returns the htr of the found block and returns this + the value of state_root from the block
 func (c *Client) GetWeakSubjectivity(ctx context.Context) (*WeakSubjectivityData, error) {
-	body, err := c.Get(ctx, getWeakSubjectivityPath)
+	body, err := c.Get(ctx, GetWeakSubjectivityPath)
 	if err != nil {
 		return nil, err
 	}

api/client/beacon/client_test.go

@@ -97,31 +97,31 @@ func TestValidHostname(t *testing.T) {
 		{
 			name:    "hostname with port",
 			hostArg: "mydomain.org:3500",
-			path:    getNodeVersionPath,
+			path:    GetNodeVersionPath,
 			joined:  "http://mydomain.org:3500/eth/v1/node/version",
 		},
 		{
 			name:    "https scheme, hostname with port",
 			hostArg: "https://mydomain.org:3500",
-			path:    getNodeVersionPath,
+			path:    GetNodeVersionPath,
 			joined:  "https://mydomain.org:3500/eth/v1/node/version",
 		},
 		{
 			name:    "http scheme, hostname without port",
 			hostArg: "http://mydomain.org",
-			path:    getNodeVersionPath,
+			path:    GetNodeVersionPath,
 			joined:  "http://mydomain.org/eth/v1/node/version",
 		},
 		{
 			name:    "http scheme, trailing slash, hostname without port",
 			hostArg: "http://mydomain.org/",
-			path:    getNodeVersionPath,
+			path:    GetNodeVersionPath,
 			joined:  "http://mydomain.org/eth/v1/node/version",
 		},
 		{
 			name:    "http scheme, hostname with basic auth creds and no port",
 			hostArg: "http://username:pass@mydomain.org/",
-			path:    getNodeVersionPath,
+			path:    GetNodeVersionPath,
 			joined:  "http://username:pass@mydomain.org/eth/v1/node/version",
 		},
 	}