beaconserver: simulated beacon api server for op-stack (#2678)

only some necessary apis are implemented.

beacon/fakebeacon/api_func.go

@@ -0,0 +1,87 @@
+package fakebeacon
+
+import (
+	"context"
+	"sort"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto/kzg4844"
+	"github.com/ethereum/go-ethereum/internal/ethapi"
+	"github.com/ethereum/go-ethereum/log"
+	"github.com/ethereum/go-ethereum/rpc"
+)
+
+type BlobSidecar struct {
+	Blob          kzg4844.Blob       `json:"blob"`
+	Index         int                `json:"index"`
+	KZGCommitment kzg4844.Commitment `json:"kzg_commitment"`
+	KZGProof      kzg4844.Proof      `json:"kzg_proof"`
+}
+
+type APIGetBlobSidecarsResponse struct {
+	Data []*BlobSidecar `json:"data"`
+}
+
+type ReducedGenesisData struct {
+	GenesisTime string `json:"genesis_time"`
+}
+
+type APIGenesisResponse struct {
+	Data ReducedGenesisData `json:"data"`
+}
+
+type ReducedConfigData struct {
+	SecondsPerSlot string `json:"SECONDS_PER_SLOT"`
+}
+
+type IndexedBlobHash struct {
+	Index int         // absolute index in the block, a.k.a. position in sidecar blobs array
+	Hash  common.Hash // hash of the blob, used for consistency checks
+}
+
+func configSpec() ReducedConfigData {
+	return ReducedConfigData{SecondsPerSlot: "1"}
+}
+
+func beaconGenesis() APIGenesisResponse {
+	return APIGenesisResponse{Data: ReducedGenesisData{GenesisTime: "0"}}
+}
+
+func beaconBlobSidecars(ctx context.Context, backend ethapi.Backend, slot uint64, indices []int) (APIGetBlobSidecarsResponse, error) {
+	var blockNrOrHash rpc.BlockNumberOrHash
+	header, err := fetchBlockNumberByTime(ctx, int64(slot), backend)
+	if err != nil {
+		log.Error("Error fetching block number", "slot", slot, "indices", indices)
+		return APIGetBlobSidecarsResponse{}, err
+	}
+	sideCars, err := backend.GetBlobSidecars(ctx, header.Hash())
+	if err != nil {
+		log.Error("Error fetching Sidecars", "blockNrOrHash", blockNrOrHash, "err", err)
+		return APIGetBlobSidecarsResponse{}, err
+	}
+	sort.Ints(indices)
+	fullBlob := len(indices) == 0
+	res := APIGetBlobSidecarsResponse{}
+	idx := 0
+	curIdx := 0
+	for _, sideCar := range sideCars {
+		for i := 0; i < len(sideCar.Blobs); i++ {
+			//hash := kZGToVersionedHash(sideCar.Commitments[i])
+			if !fullBlob && curIdx >= len(indices) {
+				break
+			}
+			if fullBlob || idx == indices[curIdx] {
+				res.Data = append(res.Data, &BlobSidecar{
+					Index:         idx,
+					Blob:          sideCar.Blobs[i],
+					KZGCommitment: sideCar.Commitments[i],
+					KZGProof:      sideCar.Proofs[i],
+				})
+				curIdx++
+			}
+			idx++
+		}
+	}
+
+	return res, nil
+}

beacon/fakebeacon/handlers.go

@@ -0,0 +1,88 @@
+package fakebeacon
+
+import (
+	"fmt"
+	"net/http"
+	"net/url"
+	"strconv"
+	"strings"
+
+	"github.com/prysmaticlabs/prysm/v5/api/server/structs"
+	field_params "github.com/prysmaticlabs/prysm/v5/config/fieldparams"
+	"github.com/prysmaticlabs/prysm/v5/network/httputil"
+)
+
+var (
+	versionMethod        = "/eth/v1/node/version"
+	specMethod           = "/eth/v1/config/spec"
+	genesisMethod        = "/eth/v1/beacon/genesis"
+	sidecarsMethodPrefix = "/eth/v1/beacon/blob_sidecars/{slot}"
+)
+
+func VersionMethod(w http.ResponseWriter, r *http.Request) {
+	resp := &structs.GetVersionResponse{
+		Data: &structs.Version{
+			Version: "",
+		},
+	}
+	httputil.WriteJson(w, resp)
+}
+
+func SpecMethod(w http.ResponseWriter, r *http.Request) {
+	httputil.WriteJson(w, &structs.GetSpecResponse{Data: configSpec()})
+}
+
+func GenesisMethod(w http.ResponseWriter, r *http.Request) {
+	httputil.WriteJson(w, beaconGenesis())
+}
+
+func (s *Service) SidecarsMethod(w http.ResponseWriter, r *http.Request) {
+	indices, err := parseIndices(r.URL)
+	if err != nil {
+		httputil.HandleError(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	segments := strings.Split(r.URL.Path, "/")
+	slot, err := strconv.ParseUint(segments[len(segments)-1], 10, 64)
+	if err != nil {
+		httputil.HandleError(w, "not a valid slot(timestamp)", http.StatusBadRequest)
+		return
+	}
+
+	resp, err := beaconBlobSidecars(r.Context(), s.backend, slot, indices)
+	if err != nil {
+		httputil.HandleError(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+	httputil.WriteJson(w, resp)
+}
+
+// parseIndices filters out invalid and duplicate blob indices
+func parseIndices(url *url.URL) ([]int, error) {
+	rawIndices := url.Query()["indices"]
+	indices := make([]int, 0, field_params.MaxBlobsPerBlock)
+	invalidIndices := make([]string, 0)
+loop:
+	for _, raw := range rawIndices {
+		ix, err := strconv.Atoi(raw)
+		if err != nil {
+			invalidIndices = append(invalidIndices, raw)
+			continue
+		}
+		if ix >= field_params.MaxBlobsPerBlock {
+			invalidIndices = append(invalidIndices, raw)
+			continue
+		}
+		for i := range indices {
+			if ix == indices[i] {
+				continue loop
+			}
+		}
+		indices = append(indices, ix)
+	}
+
+	if len(invalidIndices) > 0 {
+		return nil, fmt.Errorf("requested blob indices %v are invalid", invalidIndices)
+	}
+	return indices, nil
+}

beacon/fakebeacon/server.go

@@ -0,0 +1,97 @@
+package fakebeacon
+
+import (
+	"net/http"
+	"strconv"
+
+	"github.com/ethereum/go-ethereum/internal/ethapi"
+	"github.com/gorilla/mux"
+	"github.com/prysmaticlabs/prysm/v5/api/server"
+)
+
+const (
+	DefaultAddr = "localhost"
+	DefaultPort = 8686
+)
+
+type Config struct {
+	Enable bool
+	Addr   string
+	Port   int
+}
+
+func defaultConfig() *Config {
+	return &Config{
+		Enable: false,
+		Addr:   DefaultAddr,
+		Port:   DefaultPort,
+	}
+}
+
+type Service struct {
+	cfg     *Config
+	router  *mux.Router
+	backend ethapi.Backend
+}
+
+func NewService(cfg *Config, backend ethapi.Backend) *Service {
+	cfgs := defaultConfig()
+	if cfg.Addr != "" {
+		cfgs.Addr = cfg.Addr
+	}
+	if cfg.Port > 0 {
+		cfgs.Port = cfg.Port
+	}
+
+	s := &Service{
+		cfg:     cfgs,
+		backend: backend,
+	}
+	router := s.newRouter()
+	s.router = router
+	return s
+}
+
+func (s *Service) Run() {
+	_ = http.ListenAndServe(s.cfg.Addr+":"+strconv.Itoa(s.cfg.Port), s.router)
+}
+
+func (s *Service) newRouter() *mux.Router {
+	r := mux.NewRouter()
+	r.Use(server.NormalizeQueryValuesHandler)
+	for _, e := range s.endpoints() {
+		r.HandleFunc(e.path, e.handler).Methods(e.methods...)
+	}
+	return r
+}
+
+type endpoint struct {
+	path    string
+	handler http.HandlerFunc
+	methods []string
+}
+
+func (s *Service) endpoints() []endpoint {
+	return []endpoint{
+		{
+			path:    versionMethod,
+			handler: VersionMethod,
+			methods: []string{http.MethodGet},
+		},
+		{
+			path:    specMethod,
+			handler: SpecMethod,
+			methods: []string{http.MethodGet},
+		},
+		{
+			path:    genesisMethod,
+			handler: GenesisMethod,
+			methods: []string{http.MethodGet},
+		},
+		{
+			path:    sidecarsMethodPrefix,
+			handler: s.SidecarsMethod,
+			methods: []string{http.MethodGet},
+		},
+	}
+}

beacon/fakebeacon/server_test.go

@@ -0,0 +1,90 @@
+package fakebeacon
+
+import (
+	"context"
+	"fmt"
+	"strconv"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+//
+//func TestFetchBlockNumberByTime(t *testing.T) {
+//	blockNum, err := fetchBlockNumberByTime(context.Background(), 1724052941, client)
+//	assert.Nil(t, err)
+//	assert.Equal(t, uint64(41493946), blockNum)
+//
+//	blockNum, err = fetchBlockNumberByTime(context.Background(), 1734052941, client)
+//	assert.Equal(t, err, errors.New("time too large"))
+//
+//	blockNum, err = fetchBlockNumberByTime(context.Background(), 1600153618, client)
+//	assert.Nil(t, err)
+//	assert.Equal(t, uint64(493946), blockNum)
+//}
+//
+//func TestBeaconBlobSidecars(t *testing.T) {
+//	indexBlobHash := []IndexedBlobHash{
+//		{Hash: common.HexToHash("0x01231952ecbaede62f8d0398b656072c072db36982c9ef106fbbc39ce14f983c"), Index: 0},
+//		{Hash: common.HexToHash("0x012c21a8284d2d707bb5318e874d2e1b97a53d028e96abb702b284a2cbb0f79c"), Index: 1},
+//		{Hash: common.HexToHash("0x011196c8d02536ede0382aa6e9fdba6c460169c0711b5f97fcd701bd8997aee3"), Index: 2},
+//		{Hash: common.HexToHash("0x019c86b46b27401fb978fd175d1eb7dadf4976d6919501b0c5280d13a5bab57b"), Index: 3},
+//		{Hash: common.HexToHash("0x01e00db7ee99176b3fd50aab45b4fae953292334bbf013707aac58c455d98596"), Index: 4},
+//		{Hash: common.HexToHash("0x0117d23b68123d578a98b3e1aa029661e0abda821a98444c21992eb1e5b7208f"), Index: 5},
+//		//{Hash: common.HexToHash("0x01e00db7ee99176b3fd50aab45b4fae953292334bbf013707aac58c455d98596"), Index: 1},
+//	}
+//
+//	resp, err := beaconBlobSidecars(context.Background(), 1724055046, []int{0, 1, 2, 3, 4, 5}) // block: 41494647
+//	assert.Nil(t, err)
+//	assert.NotNil(t, resp)
+//	assert.NotEmpty(t, resp.Data)
+//	for i, sideCar := range resp.Data {
+//		assert.Equal(t, indexBlobHash[i].Index, sideCar.Index)
+//		assert.Equal(t, indexBlobHash[i].Hash, kZGToVersionedHash(sideCar.KZGCommitment))
+//	}
+//
+//	apiscs := make([]*BlobSidecar, 0, len(indexBlobHash))
+//	// filter and order by hashes
+//	for _, h := range indexBlobHash {
+//		for _, apisc := range resp.Data {
+//			if h.Index == int(apisc.Index) {
+//				apiscs = append(apiscs, apisc)
+//				break
+//			}
+//		}
+//	}
+//
+//	assert.Equal(t, len(apiscs), len(resp.Data))
+//	assert.Equal(t, len(apiscs), len(indexBlobHash))
+//}
+
+type TimeToSlotFn func(timestamp uint64) (uint64, error)
+
+// GetTimeToSlotFn returns a function that converts a timestamp to a slot number.
+func GetTimeToSlotFn(ctx context.Context) (TimeToSlotFn, error) {
+	genesis := beaconGenesis()
+	config := configSpec()
+
+	genesisTime, _ := strconv.ParseUint(genesis.Data.GenesisTime, 10, 64)
+	secondsPerSlot, _ := strconv.ParseUint(config.SecondsPerSlot, 10, 64)
+	if secondsPerSlot == 0 {
+		return nil, fmt.Errorf("got bad value for seconds per slot: %v", config.SecondsPerSlot)
+	}
+	timeToSlotFn := func(timestamp uint64) (uint64, error) {
+		if timestamp < genesisTime {
+			return 0, fmt.Errorf("provided timestamp (%v) precedes genesis time (%v)", timestamp, genesisTime)
+		}
+		return (timestamp - genesisTime) / secondsPerSlot, nil
+	}
+	return timeToSlotFn, nil
+}
+
+func TestAPI(t *testing.T) {
+	slotFn, err := GetTimeToSlotFn(context.Background())
+	assert.Nil(t, err)
+
+	expTx := uint64(123151345)
+	gotTx, err := slotFn(expTx)
+	assert.Nil(t, err)
+	assert.Equal(t, expTx, gotTx)
+}