path: root/dashboard/dashboard.go

// Copyright 2017 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 dashboard

//go:generate yarn --cwd ./assets install
//go:generate yarn --cwd ./assets build
//go:generate go-bindata -nometadata -o assets.go -prefix assets -nocompress -pkg dashboard assets/index.html assets/bundle.js
//go:generate sh -c "sed 's#var _bundleJs#//nolint:misspell\\\n&#' assets.go > assets.go.tmp && mv assets.go.tmp assets.go"
//go:generate sh -c "sed 's#var _indexHtml#//nolint:misspell\\\n&#' assets.go > assets.go.tmp && mv assets.go.tmp assets.go"
//go:generate gofmt -w -s assets.go

import (
    "fmt"
    "net"
    "net/http"
    "runtime"
    "sync"
    "sync/atomic"
    "time"

    "io"

    "github.com/dexon-foundation/dexon/log"
    "github.com/dexon-foundation/dexon/metrics"
    "github.com/dexon-foundation/dexon/p2p"
    "github.com/dexon-foundation/dexon/params"
    "github.com/dexon-foundation/dexon/rpc"
    "github.com/elastic/gosigar"
    "github.com/mohae/deepcopy"
    "golang.org/x/net/websocket"
)

const (
    activeMemorySampleLimit   = 200 // Maximum number of active memory data samples
    virtualMemorySampleLimit  = 200 // Maximum number of virtual memory data samples
    networkIngressSampleLimit = 200 // Maximum number of network ingress data samples
    networkEgressSampleLimit  = 200 // Maximum number of network egress data samples
    processCPUSampleLimit     = 200 // Maximum number of process cpu data samples
    systemCPUSampleLimit      = 200 // Maximum number of system cpu data samples
    diskReadSampleLimit       = 200 // Maximum number of disk read data samples
    diskWriteSampleLimit      = 200 // Maximum number of disk write data samples
)

var nextID uint32 // Next connection id

// Dashboard contains the dashboard internals.
type Dashboard struct {
    config *Config

    listener net.Listener
    conns    map[uint32]*client // Currently live websocket connections
    history  *Message
    lock     sync.RWMutex // Lock protecting the dashboard's internals

    logdir string

    quit chan chan error // Channel used for graceful exit
    wg   sync.WaitGroup
}

// client represents active websocket connection with a remote browser.
type client struct {
    conn   *websocket.Conn // Particular live websocket connection
    msg    chan *Message   // Message queue for the update messages
    logger log.Logger      // Logger for the particular live websocket connection
}

// New creates a new dashboard instance with the given configuration.
func New(config *Config, commit string, logdir string) *Dashboard {
    now := time.Now()
    versionMeta := ""
    if len(params.VersionMeta) > 0 {
        versionMeta = fmt.Sprintf(" (%s)", params.VersionMeta)
    }
    return &Dashboard{
        conns:  make(map[uint32]*client),
        config: config,
        quit:   make(chan chan error),
        history: &Message{
            General: &GeneralMessage{
                Commit:  commit,
                Version: fmt.Sprintf("v%d.%d.%d%s", params.VersionMajor, params.VersionMinor, params.VersionPatch, versionMeta),
            },
            System: &SystemMessage{
                ActiveMemory:   emptyChartEntries(now, activeMemorySampleLimit, config.Refresh),
                VirtualMemory:  emptyChartEntries(now, virtualMemorySampleLimit, config.Refresh),
                NetworkIngress: emptyChartEntries(now, networkIngressSampleLimit, config.Refresh),
                NetworkEgress:  emptyChartEntries(now, networkEgressSampleLimit, config.Refresh),
                ProcessCPU:     emptyChartEntries(now, processCPUSampleLimit, config.Refresh),
                SystemCPU:      emptyChartEntries(now, systemCPUSampleLimit, config.Refresh),
                DiskRead:       emptyChartEntries(now, diskReadSampleLimit, config.Refresh),
                DiskWrite:      emptyChartEntries(now, diskWriteSampleLimit, config.Refresh),
            },
        },
        logdir: logdir,
    }
}

// emptyChartEntries returns a ChartEntry array containing limit number of empty samples.
func emptyChartEntries(t time.Time, limit int, refresh time.Duration) ChartEntries {
    ce := make(ChartEntries, limit)
    for i := 0; i < limit; i++ {
        ce[i] = &ChartEntry{
            Time: t.Add(-time.Duration(i) * refresh),
        }
    }
    return ce
}

// Protocols implements the node.Service interface.
func (db *Dashboard) Protocols() []p2p.Protocol { return nil }

// APIs implements the node.Service interface.
func (db *Dashboard) APIs() []rpc.API { return nil }

// Start starts the data collection thread and the listening server of the dashboard.
// Implements the node.Service interface.
func (db *Dashboard) Start(server *p2p.Server) error {
    log.Info("Starting dashboard")

    db.wg.Add(2)
    go db.collectData()
    go db.streamLogs()

    http.HandleFunc("/", db.webHandler)
    http.Handle("/api", websocket.Handler(db.apiHandler))

    listener, err := net.Listen("tcp", fmt.Sprintf("%s:%d", db.config.Host, db.config.Port))
    if err != nil {
        return err
    }
    db.listener = listener

    go http.Serve(listener, nil)

    return nil
}

// Stop stops the data collection thread and the connection listener of the dashboard.
// Implements the node.Service interface.
func (db *Dashboard) Stop() error {
    // Close the connection listener.
    var errs []error
    if err := db.listener.Close(); err != nil {
        errs = append(errs, err)
    }
    // Close the collectors.
    errc := make(chan error, 1)
    for i := 0; i < 2; i++ {
        db.quit <- errc
        if err := <-errc; err != nil {
            errs = append(errs, err)
        }
    }
    // Close the connections.
    db.lock.Lock()
    for _, c := range db.conns {
        if err := c.conn.Close(); err != nil {
            c.logger.Warn("Failed to close connection", "err", err)
        }
    }
    db.lock.Unlock()

    // Wait until every goroutine terminates.
    db.wg.Wait()
    log.Info("Dashboard stopped")

    var err error
    if len(errs) > 0 {
        err = fmt.Errorf("%v", errs)
    }

    return err
}

// webHandler handles all non-api requests, simply flattening and returning the dashboard website.
func (db *Dashboard) webHandler(w http.ResponseWriter, r *http.Request) {
    log.Debug("Request", "URL", r.URL)

    path := r.URL.String()
    if path == "/" {
        path = "/index.html"
    }
    blob, err := Asset(path[1:])
    if err != nil {
        log.Warn("Failed to load the asset", "path", path, "err", err)
        http.Error(w, "not found", http.StatusNotFound)
        return
    }
    w.Write(blob)
}

// apiHandler handles requests for the dashboard.
func (db *Dashboard) apiHandler(conn *websocket.Conn) {
    id := atomic.AddUint32(&nextID, 1)
    client := &client{
        conn:   conn,
        msg:    make(chan *Message, 128),
        logger: log.New("id", id),
    }
    done := make(chan struct{})

    // Start listening for messages to send.
    db.wg.Add(1)
    go func() {
        defer db.wg.Done()

        for {
            select {
            case <-done:
                return
            case msg := <-client.msg:
                if err := websocket.JSON.Send(client.conn, msg); err != nil {
                    client.logger.Warn("Failed to send the message", "msg", msg, "err", err)
                    client.conn.Close()
                    return
                }
            }
        }
    }()

    db.lock.Lock()
    // Send the past data.
    client.msg <- deepcopy.Copy(db.history).(*Message)
    // Start tracking the connection and drop at connection loss.
    db.conns[id] = client
    db.lock.Unlock()
    defer func() {
        db.lock.Lock()
        delete(db.conns, id)
        db.lock.Unlock()
    }()
    for {
        r := new(Request)
        if err := websocket.JSON.Receive(conn, r); err != nil {
            if err != io.EOF {
                client.logger.Warn("Failed to receive request", "err", err)
            }
            close(done)
            return
        }
        if r.Logs != nil {
            db.handleLogRequest(r.Logs, client)
        }
    }
}

// meterCollector returns a function, which retrieves a specific meter.
func meterCollector(name string) func() int64 {
    if metric := metrics.DefaultRegistry.Get(name); metric != nil {
        m := metric.(metrics.Meter)
        return func() int64 {
            return m.Count()
        }
    }
    return func() int64 {
        return 0
    }
}

// collectData collects the required data to plot on the dashboard.
func (db *Dashboard) collectData() {
    defer db.wg.Done()

    systemCPUUsage := gosigar.Cpu{}
    systemCPUUsage.Get()
    var (
        mem runtime.MemStats

        collectNetworkIngress = meterCollector("p2p/InboundTraffic")
        collectNetworkEgress  = meterCollector("p2p/OutboundTraffic")
        collectDiskRead       = meterCollector("eth/db/chaindata/disk/read")
        collectDiskWrite      = meterCollector("eth/db/chaindata/disk/write")

        prevNetworkIngress = collectNetworkIngress()
        prevNetworkEgress  = collectNetworkEgress()
        prevProcessCPUTime = getProcessCPUTime()
        prevSystemCPUUsage = systemCPUUsage
        prevDiskRead       = collectDiskRead()
        prevDiskWrite      = collectDiskWrite()

        frequency = float64(db.config.Refresh / time.Second)
        numCPU    = float64(runtime.NumCPU())
    )

    for {
        select {
        case errc := <-db.quit:
            errc <- nil
            return
        case <-time.After(db.config.Refresh):
            systemCPUUsage.Get()
            var (
                curNetworkIngress = collectNetworkIngress()
                curNetworkEgress  = collectNetworkEgress()
                curProcessCPUTime = getProcessCPUTime()
                curSystemCPUUsage = systemCPUUsage
                curDiskRead       = collectDiskRead()
                curDiskWrite      = collectDiskWrite()

                deltaNetworkIngress = float64(curNetworkIngress - prevNetworkIngress)
                deltaNetworkEgress  = float64(curNetworkEgress - prevNetworkEgress)
                deltaProcessCPUTime = curProcessCPUTime - prevProcessCPUTime
                deltaSystemCPUUsage = curSystemCPUUsage.Delta(prevSystemCPUUsage)
                deltaDiskRead       = curDiskRead - prevDiskRead
                deltaDiskWrite      = curDiskWrite - prevDiskWrite
            )
            prevNetworkIngress = curNetworkIngress
            prevNetworkEgress = curNetworkEgress
            prevProcessCPUTime = curProcessCPUTime
            prevSystemCPUUsage = curSystemCPUUsage
            prevDiskRead = curDiskRead
            prevDiskWrite = curDiskWrite

            now := time.Now()

            runtime.ReadMemStats(&mem)
            activeMemory := &ChartEntry{
                Time:  now,
                Value: float64(mem.Alloc) / frequency,
            }
            virtualMemory := &ChartEntry{
                Time:  now,
                Value: float64(mem.Sys) / frequency,
            }
            networkIngress := &ChartEntry{
                Time:  now,
                Value: deltaNetworkIngress / frequency,
            }
            networkEgress := &ChartEntry{
                Time:  now,
                Value: deltaNetworkEgress / frequency,
            }
            processCPU := &ChartEntry{
                Time:  now,
                Value: deltaProcessCPUTime / frequency / numCPU * 100,
            }
            systemCPU := &ChartEntry{
                Time:  now,
                Value: float64(deltaSystemCPUUsage.Sys+deltaSystemCPUUsage.User) / frequency / numCPU,
            }
            diskRead := &ChartEntry{
                Time:  now,
                Value: float64(deltaDiskRead) / frequency,
            }
            diskWrite := &ChartEntry{
                Time:  now,
                Value: float64(deltaDiskWrite) / frequency,
            }
            sys := db.history.System
            db.lock.Lock()
            sys.ActiveMemory = append(sys.ActiveMemory[1:], activeMemory)
            sys.VirtualMemory = append(sys.VirtualMemory[1:], virtualMemory)
            sys.NetworkIngress = append(sys.NetworkIngress[1:], networkIngress)
            sys.NetworkEgress = append(sys.NetworkEgress[1:], networkEgress)
            sys.ProcessCPU = append(sys.ProcessCPU[1:], processCPU)
            sys.SystemCPU = append(sys.SystemCPU[1:], systemCPU)
            sys.DiskRead = append(sys.DiskRead[1:], diskRead)
            sys.DiskWrite = append(sys.DiskWrite[1:], diskWrite)
            db.lock.Unlock()

            db.sendToAll(&Message{
                System: &SystemMessage{
                    ActiveMemory:   ChartEntries{activeMemory},
                    VirtualMemory:  ChartEntries{virtualMemory},
                    NetworkIngress: ChartEntries{networkIngress},
                    NetworkEgress:  ChartEntries{networkEgress},
                    ProcessCPU:     ChartEntries{processCPU},
                    SystemCPU:      ChartEntries{systemCPU},
                    DiskRead:       ChartEntries{diskRead},
                    DiskWrite:      ChartEntries{diskWrite},
                },
            })
        }
    }
}

// sendToAll sends the given message to the active dashboards.
func (db *Dashboard) sendToAll(msg *Message) {
    db.lock.Lock()
    for _, c := range db.conns {
        select {
        case c.msg <- msg:
        default:
            c.conn.Close()
        }
    }
    db.lock.Unlock()
}