add the opentelemetry tracing (#908)

* add the opentelemetry tracing

* fix the error sampler config

* 添加stream的链路跟踪

* fix the error field name

core/service/serviceconf.go

@@ -5,6 +5,7 @@ import (
 
 	"github.com/tal-tech/go-zero/core/load"
 	"github.com/tal-tech/go-zero/core/logx"
+	"github.com/tal-tech/go-zero/core/opentelemetry"
 	"github.com/tal-tech/go-zero/core/prometheus"
 	"github.com/tal-tech/go-zero/core/stat"
 )
@@ -24,11 +25,12 @@ const (
 
 // A ServiceConf is a service config.
 type ServiceConf struct {
-	Name       string
-	Log        logx.LogConf
-	Mode       string            `json:",default=pro,options=dev|test|rt|pre|pro"`
-	MetricsUrl string            `json:",optional"`
-	Prometheus prometheus.Config `json:",optional"`
+	Name          string
+	Log           logx.LogConf
+	Mode          string               `json:",default=pro,options=dev|test|rt|pre|pro"`
+	MetricsUrl    string               `json:",optional"`
+	Prometheus    prometheus.Config    `json:",optional"`
+	OpenTelemetry opentelemetry.Config `json:",optional"`
 }
 
 // MustSetUp sets up the service, exits on error.
@@ -49,6 +51,8 @@ func (sc ServiceConf) SetUp() error {
 
 	sc.initMode()
 	prometheus.StartAgent(sc.Prometheus)
+	opentelemetry.StartAgent(sc.OpenTelemetry)
+
 	if len(sc.MetricsUrl) > 0 {
 		stat.SetReportWriter(stat.NewRemoteWriter(sc.MetricsUrl))
 	}