path: root/swarm/tracing/tracing.go

package tracing

import (
    "io"
    "os"
    "strings"
    "time"

    "github.com/ethereum/go-ethereum/log"
    jaeger "github.com/uber/jaeger-client-go"
    jaegercfg "github.com/uber/jaeger-client-go/config"
    jaegerlog "github.com/uber/jaeger-client-go/log"
    cli "gopkg.in/urfave/cli.v1"
)

var Enabled bool = false

// TracingEnabledFlag is the CLI flag name to use to enable trace collections.
const TracingEnabledFlag = "tracing"

var (
    Closer io.Closer
)

var (
    TracingFlag = cli.BoolFlag{
        Name:  TracingEnabledFlag,
        Usage: "Enable tracing",
    }
    TracingEndpointFlag = cli.StringFlag{
        Name:  "tracing.endpoint",
        Usage: "Tracing endpoint",
        Value: "0.0.0.0:6831",
    }
    TracingSvcFlag = cli.StringFlag{
        Name:  "tracing.svc",
        Usage: "Tracing service name",
        Value: "swarm",
    }
)

// Flags holds all command-line flags required for tracing collection.
var Flags = []cli.Flag{
    TracingFlag,
    TracingEndpointFlag,
    TracingSvcFlag,
}

// Init enables or disables the open tracing system.
func init() {
    for _, arg := range os.Args {
        if flag := strings.TrimLeft(arg, "-"); flag == TracingEnabledFlag {
            Enabled = true
        }
    }
}

func Setup(ctx *cli.Context) {
    if Enabled {
        log.Info("Enabling opentracing")
        var (
            endpoint = ctx.GlobalString(TracingEndpointFlag.Name)
            svc      = ctx.GlobalString(TracingSvcFlag.Name)
        )

        Closer = initTracer(endpoint, svc)
    }
}

func initTracer(endpoint, svc string) (closer io.Closer) {
    // Sample configuration for testing. Use constant sampling to sample every trace
    // and enable LogSpan to log every span via configured Logger.
    cfg := jaegercfg.Configuration{
        Sampler: &jaegercfg.SamplerConfig{
            Type:  jaeger.SamplerTypeConst,
            Param: 1,
        },
        Reporter: &jaegercfg.ReporterConfig{
            LogSpans:            true,
            BufferFlushInterval: 1 * time.Second,
            LocalAgentHostPort:  endpoint,
        },
    }

    // Example logger and metrics factory. Use github.com/uber/jaeger-client-go/log
    // and github.com/uber/jaeger-lib/metrics respectively to bind to real logging and metrics
    // frameworks.
    jLogger := jaegerlog.StdLogger
    //jMetricsFactory := metrics.NullFactory

    // Initialize tracer with a logger and a metrics factory
    closer, err := cfg.InitGlobalTracer(
        svc,
        jaegercfg.Logger(jLogger),
        //jaegercfg.Metrics(jMetricsFactory),
        //jaegercfg.Observer(rpcmetrics.NewObserver(jMetricsFactory, rpcmetrics.DefaultNameNormalizer)),
    )
    if err != nil {
        log.Error("Could not initialize Jaeger tracer", "err", err)
    }

    return closer
}