aadcb88675
Here we add a beacon chain light client for use by geth. Geth can now be configured to run against a beacon chain API endpoint, without pointing a CL to it. To set this up, use the `--beacon.api` flag. Information provided by the beacon chain is verified, i.e. geth does not blindly trust the beacon API endpoint in this mode. The root of trust are the beacon chain 'sync committees'. The configured beacon API endpoint must provide light client data. At this time, only Lodestar and Nimbus provide the necessary APIs. There is also a standalone tool, cmd/blsync, which uses the beacon chain light client to drive any EL implementation via its engine API. --------- Co-authored-by: Felix Lange <fjl@twurst.com>
104 lines
4.0 KiB
Go
Executable File
104 lines
4.0 KiB
Go
Executable File
// Copyright 2023 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package api
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import (
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"reflect"
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"github.com/ethereum/go-ethereum/beacon/light/request"
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"github.com/ethereum/go-ethereum/beacon/light/sync"
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"github.com/ethereum/go-ethereum/beacon/types"
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"github.com/ethereum/go-ethereum/common"
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"github.com/ethereum/go-ethereum/log"
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)
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// ApiServer is a wrapper around BeaconLightApi that implements request.requestServer.
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type ApiServer struct {
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api *BeaconLightApi
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eventCallback func(event request.Event)
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unsubscribe func()
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}
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// NewApiServer creates a new ApiServer.
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func NewApiServer(api *BeaconLightApi) *ApiServer {
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return &ApiServer{api: api}
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}
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// Subscribe implements request.requestServer.
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func (s *ApiServer) Subscribe(eventCallback func(event request.Event)) {
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s.eventCallback = eventCallback
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listener := HeadEventListener{
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OnNewHead: func(slot uint64, blockRoot common.Hash) {
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log.Debug("New head received", "slot", slot, "blockRoot", blockRoot)
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eventCallback(request.Event{Type: sync.EvNewHead, Data: types.HeadInfo{Slot: slot, BlockRoot: blockRoot}})
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},
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OnSignedHead: func(head types.SignedHeader) {
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log.Debug("New signed head received", "slot", head.Header.Slot, "blockRoot", head.Header.Hash(), "signerCount", head.Signature.SignerCount())
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eventCallback(request.Event{Type: sync.EvNewSignedHead, Data: head})
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},
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OnFinality: func(head types.FinalityUpdate) {
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log.Debug("New finality update received", "slot", head.Attested.Slot, "blockRoot", head.Attested.Hash(), "signerCount", head.Signature.SignerCount())
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eventCallback(request.Event{Type: sync.EvNewFinalityUpdate, Data: head})
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},
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OnError: func(err error) {
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log.Warn("Head event stream error", "err", err)
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},
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}
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s.unsubscribe = s.api.StartHeadListener(listener)
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}
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// SendRequest implements request.requestServer.
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func (s *ApiServer) SendRequest(id request.ID, req request.Request) {
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go func() {
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var resp request.Response
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var err error
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switch data := req.(type) {
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case sync.ReqUpdates:
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log.Debug("Beacon API: requesting light client update", "reqid", id, "period", data.FirstPeriod, "count", data.Count)
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var r sync.RespUpdates
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r.Updates, r.Committees, err = s.api.GetBestUpdatesAndCommittees(data.FirstPeriod, data.Count)
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resp = r
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case sync.ReqHeader:
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log.Debug("Beacon API: requesting header", "reqid", id, "hash", common.Hash(data))
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resp, err = s.api.GetHeader(common.Hash(data))
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case sync.ReqCheckpointData:
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log.Debug("Beacon API: requesting checkpoint data", "reqid", id, "hash", common.Hash(data))
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resp, err = s.api.GetCheckpointData(common.Hash(data))
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case sync.ReqBeaconBlock:
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log.Debug("Beacon API: requesting block", "reqid", id, "hash", common.Hash(data))
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resp, err = s.api.GetBeaconBlock(common.Hash(data))
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default:
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}
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if err != nil {
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log.Warn("Beacon API request failed", "type", reflect.TypeOf(req), "reqid", id, "err", err)
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s.eventCallback(request.Event{Type: request.EvFail, Data: request.RequestResponse{ID: id, Request: req}})
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} else {
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s.eventCallback(request.Event{Type: request.EvResponse, Data: request.RequestResponse{ID: id, Request: req, Response: resp}})
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}
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}()
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}
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// Unsubscribe implements request.requestServer.
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// Note: Unsubscribe should not be called concurrently with Subscribe.
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func (s *ApiServer) Unsubscribe() {
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if s.unsubscribe != nil {
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s.unsubscribe()
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s.unsubscribe = nil
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}
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}
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