makes jaeger tracing configurable

conf/defaults.ini

@@ -452,6 +452,11 @@ url = https://grafana.com
 [grafana_com]
 url = https://grafana.com
 
+#################################### Distributed tracing ############
+[tracing.jaeger]
+# jaeger destination (ex localhost:5775)
+address =
+
 #################################### External Image Storage ##############
 [external_image_storage]
 # You can choose between (s3, webdav, gcs)

conf/sample.ini

@@ -391,6 +391,11 @@
 ;address =
 ;prefix = prod.grafana.%(instance_name)s.
 
+#################################### Distributed tracing ############
+[tracing.jaeger]
+# Enable by setting the address sending traces to jaeger (ex localhost:5775)
+;address = localhost:5775
+
 #################################### Grafana.com integration  ##########################
 # Url used to to import dashboards directly from Grafana.com
 [grafana_com]

pkg/cmd/grafana-server/server.go

@@ -24,10 +24,7 @@ import (
 	"github.com/grafana/grafana/pkg/services/search"
 	"github.com/grafana/grafana/pkg/setting"
 	"github.com/grafana/grafana/pkg/social"
-	opentracing "github.com/opentracing/opentracing-go"
-	jaeger "github.com/uber/jaeger-client-go"
-	jaegercfg "github.com/uber/jaeger-client-go/config"
-	jaegerlog "github.com/uber/jaeger-client-go/log"
+	"github.com/grafana/grafana/pkg/tracing"
 )
 
 func NewGrafanaServer() models.GrafanaServer {
@@ -65,33 +62,12 @@ func (g *GrafanaServerImpl) Start() {
 	eventpublisher.Init()
 	plugins.Init()
 
-	//localhost:5775
-
-	cfg := jaegercfg.Configuration{
-		Disabled: false,
-		Sampler: &jaegercfg.SamplerConfig{
-			Type:  jaeger.SamplerTypeConst,
-			Param: 1,
-		},
-		Reporter: &jaegercfg.ReporterConfig{
-			LogSpans:           false,
-			LocalAgentHostPort: "localhost:5775",
-		},
-	}
-
-	jLogger := jaegerlog.StdLogger
-
-	tracer, closer, err := cfg.New(
-		"grafana",
-		jaegercfg.Logger(jLogger),
-	)
+	closer, err := tracing.Init(setting.Cfg)
 	if err != nil {
-		g.log.Error("tracing", "error", err)
+		g.log.Error("Tracing settings is not valid", "error", err)
 		g.Shutdown(1, "Startup failed")
 		return
 	}
-
-	opentracing.InitGlobalTracer(tracer)
 	defer closer.Close()
 
 	// init alerting
@@ -104,7 +80,7 @@ func (g *GrafanaServerImpl) Start() {
 	cleanUpService := cleanup.NewCleanUpService()
 	g.childRoutines.Go(func() error { return cleanUpService.Run(g.context) })
 
-	if err := notifications.Init(); err != nil {
+	if err = notifications.Init(); err != nil {
 		g.log.Error("Notification service failed to initialize", "error", err)
 		g.Shutdown(1, "Startup failed")
 		return

pkg/tracing/tracing.go

+package tracing
+
+import (
+	"io"
+	"io/ioutil"
+
+	"github.com/grafana/grafana/pkg/log"
+	"github.com/grafana/grafana/pkg/setting"
+
+	opentracing "github.com/opentracing/opentracing-go"
+	jaeger "github.com/uber/jaeger-client-go"
+	jaegercfg "github.com/uber/jaeger-client-go/config"
+	jaegerlog "github.com/uber/jaeger-client-go/log"
+	ini "gopkg.in/ini.v1"
+)
+
+var (
+	logger log.Logger = log.New("tracing")
+)
+
+type TracingSettings struct {
+	Enabled bool
+	Address string
+}
+
+func Init(file *ini.File) (io.Closer, error) {
+	settings := parseSettings(file)
+	return internalInit(settings)
+}
+
+func parseSettings(file *ini.File) *TracingSettings {
+	settings := &TracingSettings{}
+
+	var section, err = setting.Cfg.GetSection("tracing.jaeger")
+	if err != nil {
+		return settings
+	}
+
+	settings.Address = section.Key("address").MustString("")
+	if settings.Address != "" {
+		settings.Enabled = true
+	}
+
+	return settings
+}
+
+func internalInit(settings *TracingSettings) (io.Closer, error) {
+	if !settings.Enabled {
+		return ioutil.NopCloser(nil), nil
+	}
+
+	cfg := jaegercfg.Configuration{
+		Disabled: !settings.Enabled,
+		Sampler: &jaegercfg.SamplerConfig{
+			Type:  jaeger.SamplerTypeConst,
+			Param: 1,
+		},
+		Reporter: &jaegercfg.ReporterConfig{
+			LogSpans:           false,
+			LocalAgentHostPort: settings.Address,
+		},
+	}
+
+	jLogger := jaegerlog.StdLogger
+
+	tracer, closer, err := cfg.New(
+		"grafana",
+		jaegercfg.Logger(jLogger),
+	)
+	if err != nil {
+		return nil, err
+	}
+
+	logger.Info("Initialized jaeger tracer", "address", settings.Address)
+	opentracing.InitGlobalTracer(tracer)
+	return closer, nil
+}