path: root/ethstats/ethstats.go

// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

// Package ethstats implements the network stats reporting service.
package ethstats

import (
    "encoding/json"
    "errors"
    "fmt"
    "math/big"
    "regexp"
    "runtime"
    "strconv"
    "time"

    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/core"
    "github.com/ethereum/go-ethereum/core/types"
    "github.com/ethereum/go-ethereum/eth"
    "github.com/ethereum/go-ethereum/event"
    "github.com/ethereum/go-ethereum/les"
    "github.com/ethereum/go-ethereum/logger"
    "github.com/ethereum/go-ethereum/logger/glog"
    "github.com/ethereum/go-ethereum/node"
    "github.com/ethereum/go-ethereum/p2p"
    "github.com/ethereum/go-ethereum/rpc"
    "golang.org/x/net/websocket"
)

// Service implements an Ethereum netstats reporting daemon that pushes local
// chain statistics up to a monitoring server.
type Service struct {
    stack *node.Node // Temporary workaround, remove when API finalized

    server *p2p.Server        // Peer-to-peer server to retrieve networking infos
    eth    *eth.Ethereum      // Full Ethereum service if monitoring a full node
    les    *les.LightEthereum // Light Ethereum service if monitoring a light node

    node string // Name of the node to display on the monitoring page
    pass string // Password to authorize access to the monitoring page
    host string // Remote address of the monitoring service
}

// New returns a monitoring service ready for stats reporting.
func New(url string, ethServ *eth.Ethereum, lesServ *les.LightEthereum) (*Service, error) {
    // Parse the netstats connection url
    re := regexp.MustCompile("([^:@]*)(:([^@]*))?@(.+)")
    parts := re.FindStringSubmatch(url)
    if len(parts) != 5 {
        return nil, fmt.Errorf("invalid netstats url: \"%s\", should be nodename:secret@host:port", url)
    }
    // Assemble and return the stats service
    return &Service{
        eth:  ethServ,
        les:  lesServ,
        node: parts[1],
        pass: parts[3],
        host: parts[4],
    }, nil
}

// Protocols implements node.Service, returning the P2P network protocols used
// by the stats service (nil as it doesn't use the devp2p overlay network).
func (s *Service) Protocols() []p2p.Protocol { return nil }

// APIs implements node.Service, returning the RPC API endpoints provided by the
// stats service (nil as it doesn't provide any user callable APIs).
func (s *Service) APIs() []rpc.API { return nil }

// Start implements node.Service, starting up the monitoring and reporting daemon.
func (s *Service) Start(server *p2p.Server) error {
    s.server = server
    go s.loop()

    glog.V(logger.Info).Infoln("Stats daemon started")
    return nil
}

// Stop implements node.Service, terminating the monitoring and reporting daemon.
func (s *Service) Stop() error {
    glog.V(logger.Info).Infoln("Stats daemon stopped")
    return nil
}

// loop keeps trying to connect to the netstats server, reporting chain events
// until termination.
func (s *Service) loop() {
    // Subscribe tso chain events to execute updates on
    var emux *event.TypeMux
    if s.eth != nil {
        emux = s.eth.EventMux()
    } else {
        emux = s.les.EventMux()
    }
    headSub := emux.Subscribe(core.ChainHeadEvent{})
    defer headSub.Unsubscribe()

    txSub := emux.Subscribe(core.TxPreEvent{})
    defer txSub.Unsubscribe()

    // Loop reporting until termination
    for {
        // Establish a websocket connection to the server and authenticate the node
        conn, err := websocket.Dial(fmt.Sprintf("wss://%s/api", s.host), "", "http://localhost/")
        if err != nil {
            glog.V(logger.Warn).Infof("Stats server unreachable: %v", err)
            time.Sleep(10 * time.Second)
            continue
        }
        in := json.NewDecoder(conn)
        out := json.NewEncoder(conn)

        if err = s.login(in, out); err != nil {
            glog.V(logger.Warn).Infof("Stats login failed: %v", err)
            conn.Close()
            time.Sleep(10 * time.Second)
            continue
        }
        if err = s.report(in, out); err != nil {
            glog.V(logger.Warn).Infof("Initial stats report failed: %v", err)
            conn.Close()
            continue
        }
        // Keep sending status updates until the connection breaks
        fullReport := time.NewTicker(15 * time.Second)

        for err == nil {
            select {
            case <-fullReport.C:
                if err = s.report(in, out); err != nil {
                    glog.V(logger.Warn).Infof("Full stats report failed: %v", err)
                }
            case <-headSub.Chan():
                // Exhaust events to avoid reporting too frequently
                for exhausted := false; !exhausted; {
                    select {
                    case <-headSub.Chan():
                    default:
                        exhausted = true
                    }
                }
                if err = s.reportBlock(out); err != nil {
                    glog.V(logger.Warn).Infof("Block stats report failed: %v", err)
                }
            case <-txSub.Chan():
                // Exhaust events to avoid reporting too frequently
                for exhausted := false; !exhausted; {
                    select {
                    case <-headSub.Chan():
                    default:
                        exhausted = true
                    }
                }
                if err = s.reportPending(out); err != nil {
                    glog.V(logger.Warn).Infof("Transaction stats report failed: %v", err)
                }
            }
        }
        // Make sure the connection is closed
        conn.Close()
    }
}

// nodeInfo is the collection of metainformation about a node that is displayed
// on the monitoring page.
type nodeInfo struct {
    Name     string `json:"name"`
    Node     string `json:"node"`
    Port     int    `json:"port"`
    Network  string `json:"net"`
    Protocol string `json:"protocol"`
    API      string `json:"api"`
    Os       string `json:"os"`
    OsVer    string `json:"os_v"`
    Client   string `json:"client"`
}

// authMsg is the authentication infos needed to login to a monitoring server.
type authMsg struct {
    Id     string   `json:"id"`
    Info   nodeInfo `json:"info"`
    Secret string   `json:"secret"`
}

// login tries to authorize the client at the remote server.
func (s *Service) login(in *json.Decoder, out *json.Encoder) error {
    // Construct and send the login authentication
    infos := s.server.NodeInfo()

    var network, protocol string
    if info := infos.Protocols["eth"]; info != nil {
        network = strconv.Itoa(info.(*eth.EthNodeInfo).Network)
        protocol = fmt.Sprintf("eth/%d", eth.ProtocolVersions[0])
    } else {
        network = strconv.Itoa(infos.Protocols["les"].(*eth.EthNodeInfo).Network)
        protocol = fmt.Sprintf("les/%d", les.ProtocolVersions[0])
    }
    auth := &authMsg{
        Id: s.node,
        Info: nodeInfo{
            Name:     s.node,
            Node:     infos.Name,
            Port:     infos.Ports.Listener,
            Network:  network,
            Protocol: protocol,
            API:      "No",
            Os:       runtime.GOOS,
            OsVer:    runtime.GOARCH,
            Client:   "0.1.1",
        },
        Secret: s.pass,
    }
    login := map[string][]interface{}{
        "emit": []interface{}{"hello", auth},
    }
    if err := out.Encode(login); err != nil {
        return err
    }
    // Retrieve the remote ack or connection termination
    var ack map[string][]string
    if err := in.Decode(&ack); err != nil || len(ack["emit"]) != 1 || ack["emit"][0] != "ready" {
        return errors.New("unauthorized")
    }
    return nil
}

// report collects all possible data to report and send it to the stats server.
// This should only be used on reconnects or rarely to avoid overloading the
// server. Use the individual methods for reporting subscribed events.
func (s *Service) report(in *json.Decoder, out *json.Encoder) error {
    if err := s.reportLatency(in, out); err != nil {
        return err
    }
    if err := s.reportBlock(out); err != nil {
        return err
    }
    if err := s.reportPending(out); err != nil {
        return err
    }
    if err := s.reportStats(out); err != nil {
        return err
    }
    return nil
}

// reportLatency sends a ping request to the server, measures the RTT time and
// finally sends a latency update.
func (s *Service) reportLatency(in *json.Decoder, out *json.Encoder) error {
    // Send the current time to the ethstats server
    start := time.Now()

    ping := map[string][]interface{}{
        "emit": []interface{}{"node-ping", map[string]string{
            "id":         s.node,
            "clientTime": start.String(),
        }},
    }
    if err := out.Encode(ping); err != nil {
        return err
    }
    // Wait for the pong request to arrive back
    var pong map[string][]interface{}
    if err := in.Decode(&pong); err != nil || len(pong["emit"]) != 2 || pong["emit"][0].(string) != "node-pong" {
        return errors.New("unexpected ping reply")
    }
    // Send back the measured latency
    latency := map[string][]interface{}{
        "emit": []interface{}{"latency", map[string]string{
            "id":      s.node,
            "latency": strconv.Itoa(int((time.Since(start) / time.Duration(2)).Nanoseconds() / 1000000)),
        }},
    }
    if err := out.Encode(latency); err != nil {
        return err
    }
    return nil
}

// blockStats is the information to report about individual blocks.
type blockStats struct {
    Number    *big.Int    `json:"number"`
    Hash      common.Hash `json:"hash"`
    Diff      string      `json:"difficulty"`
    TotalDiff string      `json:"totalDifficulty"`
    Txs       txStats     `json:"transactions"`
    Uncles    uncleStats  `json:"uncles"`
}

// txStats is a custom wrapper around a transaction array to force serializing
// empty arrays instead of returning null for them.
type txStats []*types.Transaction

func (s txStats) MarshalJSON() ([]byte, error) {
    if txs := ([]*types.Transaction)(s); len(txs) > 0 {
        return json.Marshal(txs)
    }
    return []byte("[]"), nil
}

// uncleStats is a custom wrapper around an uncle array to force serializing
// empty arrays instead of returning null for them.
type uncleStats []*types.Header

func (s uncleStats) MarshalJSON() ([]byte, error) {
    if uncles := ([]*types.Header)(s); len(uncles) > 0 {
        return json.Marshal(uncles)
    }
    return []byte("[]"), nil
}

// reportBlock retrieves the current chain head and repors it to the stats server.
func (s *Service) reportBlock(out *json.Encoder) error {
    // Gather the head block infos from the local blockchain
    var (
        head   *types.Header
        td     *big.Int
        txs    []*types.Transaction
        uncles []*types.Header
    )
    if s.eth != nil {
        // Full nodes have all needed information available
        block := s.eth.BlockChain().CurrentBlock()

        head = s.eth.BlockChain().CurrentHeader()
        td = s.eth.BlockChain().GetTd(head.Hash(), head.Number.Uint64())

        txs = block.Transactions()
        uncles = block.Uncles()
    } else {
        // Light nodes would need on-demand lookups for transactions/uncles, skip
        head = s.les.BlockChain().CurrentHeader()
        td = s.les.BlockChain().GetTd(head.Hash(), head.Number.Uint64())
    }
    // Assemble the block stats report and send it to the server
    stats := map[string]interface{}{
        "id": s.node,
        "block": &blockStats{
            Number:    head.Number,
            Hash:      head.Hash(),
            Diff:      head.Difficulty.String(),
            TotalDiff: td.String(),
            Txs:       txs,
            Uncles:    uncles,
        },
    }
    report := map[string][]interface{}{
        "emit": []interface{}{"block", stats},
    }
    if err := out.Encode(report); err != nil {
        return err
    }
    return nil
}

// pendStats is the information to report about pending transactions.
type pendStats struct {
    Pending int `json:"pending"`
}

// reportPending retrieves the current number of pending transactions and reports
// it to the stats server.
func (s *Service) reportPending(out *json.Encoder) error {
    // Retrieve the pending count from the local blockchain
    var pending int
    if s.eth != nil {
        pending, _ = s.eth.TxPool().Stats()
    } else {
        pending = s.les.TxPool().Stats()
    }
    // Assemble the transaction stats and send it to the server
    stats := map[string]interface{}{
        "id": s.node,
        "stats": &pendStats{
            Pending: pending,
        },
    }
    report := map[string][]interface{}{
        "emit": []interface{}{"pending", stats},
    }
    if err := out.Encode(report); err != nil {
        return err
    }
    return nil
}

// blockStats is the information to report about the local node.
type nodeStats struct {
    Active   bool `json:"active"`
    Syncing  bool `json:"syncing"`
    Mining   bool `json:"mining"`
    Hashrate int  `json:"hashrate"`
    Peers    int  `json:"peers"`
    GasPrice int  `json:"gasPrice"`
    Uptime   int  `json:"uptime"`
}

// reportPending retrieves various stats about the node at the networking and
// mining layer and reports it to the stats server.
func (s *Service) reportStats(out *json.Encoder) error {
    // Gather the syncing and mining infos from the local miner instance
    var (
        mining   bool
        hashrate int
        syncing  bool
        gasprice int
    )
    if s.eth != nil {
        mining = s.eth.Miner().Mining()
        hashrate = int(s.eth.Miner().HashRate())

        sync := s.eth.Downloader().Progress()
        syncing = s.eth.BlockChain().CurrentHeader().Number.Uint64() >= sync.HighestBlock

        gasprice = int(s.eth.Miner().GasPrice().Uint64())
    } else {
        sync := s.les.Downloader().Progress()
        syncing = s.les.BlockChain().CurrentHeader().Number.Uint64() >= sync.HighestBlock
    }
    stats := map[string]interface{}{
        "id": s.node,
        "stats": &nodeStats{
            Active:   true,
            Mining:   mining,
            Hashrate: hashrate,
            Peers:    s.server.PeerCount(),
            GasPrice: gasprice,
            Syncing:  syncing,
            Uptime:   100,
        },
    }
    report := map[string][]interface{}{
        "emit": []interface{}{"stats", stats},
    }
    if err := out.Encode(report); err != nil {
        return err
    }
    return nil
}