Merge pull request #2 from duanxinDX/xin_jaeger

feat: add jaeger middleware

glide.yaml

@@ -22,4 +22,8 @@ import:
 - package: github.com/getsentry/raven-go
 - package: github.com/levigross/grequests
   version: ~0.9
-- package: github.com/CrowdSurge/banner
+- package: github.com/CrowdSurge/banner
+- package: github.com/uber/jaeger-client-go
+  version: 2.14.0
+- package: github.com/opentracing/opentracing-go
+  version: 1.0.2

jaeger/init.go

@@ -0,0 +1,76 @@
+package jaeger
+
+import (
+	"fmt"
+	"os"
+	"strings"
+	"strconv"
+	"time"
+
+	"github.com/lingmiaotech/tonic/configs"
+	"github.com/opentracing/opentracing-go"
+	"github.com/uber/jaeger-client-go"
+	"github.com/uber/jaeger-client-go/config"
+	"github.com/uber/jaeger-client-go/transport"
+)
+
+func Initialize() {
+
+	var sampleStrategy string
+	if sampleStrategy = os.Getenv("SAMPLE_STRATEGY"); sampleStrategy == ""{
+		sampleStrategy = "probabilistic,0.2"
+	}
+	args := strings.Split(sampleStrategy, ",")
+	if len(args) != 2 {
+		panic(fmt.Sprintf("ERROR: invalid SAMPLE_STRATEGY format %s", sampleStrategy))
+	}
+	samplerType := args[0]
+	param, err := strconv.ParseFloat(args[1], 64)
+	if err != nil {
+		panic(fmt.Sprintf("ERROR: invalid SAMPLE_STRATEGY param %s, param must be string of float64", sampleStrategy))
+	}
+
+	cfg := &config.Configuration{
+		ServiceName: configs.GetString("app_name"),
+		Sampler: &config.SamplerConfig{
+			Type:  samplerType,
+			Param: param,
+		},
+	}
+
+	var agentURI string
+	if agentURI = os.Getenv("JAEGER_AGENT"); agentURI == "" {
+		agentURI = fmt.Sprintf("http://jaeger-agent.%s:6831", configs.GetString("app_name"))
+	}
+
+	var backendHostPort string
+	if env, _ := configs.Get("env").(string); env == "production" {
+		backendHostPort = agentURI
+	}else {
+		backendHostPort = "127.0.0.1:6831"
+	}
+
+	var sender jaeger.Transport
+	if strings.HasPrefix(backendHostPort, "http://") {
+		sender = transport.NewHTTPTransport(
+			backendHostPort,
+			transport.HTTPBatchSize(1),
+		)
+	} else {
+		sender, err = jaeger.NewUDPTransport(backendHostPort, 0)
+		if err != nil {
+			panic(fmt.Sprintf("ERROR: cannot initialize UDP sender: %v\n", err))
+		}
+	}
+
+	tracer, _, err := cfg.NewTracer(
+		config.Reporter(jaeger.NewRemoteReporter(
+			sender,
+			jaeger.ReporterOptions.BufferFlushInterval(1*time.Second),
+		)))
+	if err != nil {
+		panic(fmt.Sprintf("ERROR: cannot init Jaeger: %v\n", err))
+	}
+	opentracing.InitGlobalTracer(tracer)
+	return
+}

server.go

@@ -7,9 +7,12 @@ import (
 
 	"github.com/CrowdSurge/banner"
 	"github.com/gin-gonic/gin"
+	"github.com/opentracing/opentracing-go"
+	"github.com/opentracing/opentracing-go/ext"
 
 	"github.com/lingmiaotech/tonic/configs"
 	"github.com/lingmiaotech/tonic/database"
+	"github.com/lingmiaotech/tonic/jaeger"
 	"github.com/lingmiaotech/tonic/kafka"
 	"github.com/lingmiaotech/tonic/logging"
 	"github.com/lingmiaotech/tonic/redis"
@@ -112,13 +115,39 @@ func GetServerMode() string {
 	return gin.DebugMode
 }
 
+func InitJaeger() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		jaeger.Initialize()
+		c.Next()
+	}
+}
+
+func InitJaegerSpan() gin.HandlerFunc {
+	return func(c *gin.Context) {
+		tracer := opentracing.GlobalTracer()
+		var span opentracing.Span
+		spanContext, err := tracer.Extract(opentracing.HTTPHeaders, opentracing.HTTPHeadersCarrier(c.Request.Header))
+		if err != nil {
+			span = tracer.StartSpan("HTTP " + c.Request.Method)
+		} else {
+			span = tracer.StartSpan("HTTP "+c.Request.Method, ext.RPCServerOption(spanContext))
+		}
+		defer span.Finish()
+		ext.HTTPMethod.Set(span, c.Request.Method)
+		ext.HTTPUrl.Set(span, c.Request.URL.String())
+		ext.Component.Set(span, "net/http")
+		c.Request = c.Request.WithContext(opentracing.ContextWithSpan(c.Request.Context(), span))
+		c.Next()
+	}
+}
+
 func InitMiddlewares(app *gin.Engine) {
 	env, _ := configs.Get("env").(string)
 
 	switch env {
 	case "test":
 		app.Use(gin.LoggerWithWriter(ioutil.Discard), gin.Recovery())
 	default:
-		app.Use(gin.Logger(), gin.Recovery())
+		app.Use(gin.Logger(), gin.Recovery(), InitJaeger(), InitJaegerSpan())
 	}
 }