Add options to set tracer tags (jaegertracing#174)

config/config.go

@@ -151,6 +151,10 @@ func (c Configuration) New(
 		tracerOptions = append(tracerOptions, jaeger.TracerOptions.Observer(obs))
 	}
 
+	for _, tag := range opts.tags {
+		tracerOptions = append(tracerOptions, jaeger.TracerOptions.Tag(tag.Key, tag.Value))
+	}
+
 	tracer, closer := jaeger.NewTracer(
 		serviceName,
 		sampler,

config/options.go

@@ -21,6 +21,7 @@
 package config
 
 import (
+	opentracing "github.com/opentracing/opentracing-go"
 	"github.com/uber/jaeger-lib/metrics"
 
 	"github.com/uber/jaeger-client-go"
@@ -36,6 +37,7 @@ type Options struct {
 	reporter            jaeger.Reporter
 	observers           []jaeger.Observer
 	zipkinSharedRPCSpan bool
+	tags                []opentracing.Tag
 }
 
 // Metrics creates an Option that initializes Metrics in the tracer,
@@ -78,6 +80,13 @@ func ZipkinSharedRPCSpan(zipkinSharedRPCSpan bool) Option {
 	}
 }
 
+// Tag creates an option that adds a tracer-level tag.
+func Tag(key string, value interface{}) Option {
+	return func(c *Options) {
+		c.tags = append(c.tags, opentracing.Tag{Key: key, Value: value})
+	}
+}
+
 func applyOptions(options ...Option) Options {
 	opts := Options{}
 	for _, option := range options {

config/options_test.go

@@ -25,6 +25,7 @@ import (
 
 	opentracing "github.com/opentracing/opentracing-go"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 	"github.com/uber/jaeger-lib/metrics"
 
 	"github.com/uber/jaeger-client-go"
@@ -45,6 +46,14 @@ func TestApplyOptions(t *testing.T) {
 	assert.True(t, opts.zipkinSharedRPCSpan)
 }
 
+func TestTraceTagOption(t *testing.T) {
+	c := Configuration{}
+	tracer, closer, err := c.New("test-service", Tag("tag-key", "tag-value"))
+	require.NoError(t, err)
+	defer closer.Close()
+	assert.Equal(t, opentracing.Tag{Key: "tag-key", Value: "tag-value"}, tracer.(*jaeger.Tracer).Tags()[0])
+}
+
 func TestApplyOptionsDefaults(t *testing.T) {
 	opts := applyOptions()
 	assert.Equal(t, jaeger.NullLogger, opts.logger)

interop.go

@@ -34,7 +34,7 @@ type formatKey int
 const SpanContextFormat formatKey = iota
 
 type jaegerTraceContextPropagator struct {
-	tracer *tracer
+	tracer *Tracer
 }
 
 func (p *jaegerTraceContextPropagator) Inject(

jaeger_thrift_span.go

@@ -54,7 +54,7 @@ func BuildJaegerProcessThrift(span *Span) *j.Process {
 	return buildJaegerProcessThrift(span.tracer)
 }
 
-func buildJaegerProcessThrift(tracer *tracer) *j.Process {
+func buildJaegerProcessThrift(tracer *Tracer) *j.Process {
 	process := &j.Process{
 		ServiceName: tracer.serviceName,
 		Tags:        buildTags(tracer.tags),

propagation.go

@@ -58,12 +58,12 @@ type Extractor interface {
 }
 
 type textMapPropagator struct {
-	tracer      *tracer
+	tracer      *Tracer
 	encodeValue func(string) string
 	decodeValue func(string) string
 }
 
-func newTextMapPropagator(tracer *tracer) *textMapPropagator {
+func newTextMapPropagator(tracer *Tracer) *textMapPropagator {
 	return &textMapPropagator{
 		tracer: tracer,
 		encodeValue: func(val string) string {
@@ -75,7 +75,7 @@ func newTextMapPropagator(tracer *tracer) *textMapPropagator {
 	}
 }
 
-func newHTTPHeaderPropagator(tracer *tracer) *textMapPropagator {
+func newHTTPHeaderPropagator(tracer *Tracer) *textMapPropagator {
 	return &textMapPropagator{
 		tracer: tracer,
 		encodeValue: func(val string) string {
@@ -92,11 +92,11 @@ func newHTTPHeaderPropagator(tracer *tracer) *textMapPropagator {
 }
 
 type binaryPropagator struct {
-	tracer  *tracer
+	tracer  *Tracer
 	buffers sync.Pool
 }
 
-func newBinaryPropagator(tracer *tracer) *binaryPropagator {
+func newBinaryPropagator(tracer *Tracer) *binaryPropagator {
 	return &binaryPropagator{
 		tracer:  tracer,
 		buffers: sync.Pool{New: func() interface{} { return &bytes.Buffer{} }},

span.go

@@ -34,7 +34,7 @@ import (
 type Span struct {
 	sync.RWMutex
 
-	tracer *tracer
+	tracer *Tracer
 
 	context SpanContext
 
@@ -66,7 +66,8 @@ type Span struct {
 	observer SpanObserver
 }
 
-// Tag is a simple key value wrapper
+// Tag is a simple key value wrapper.
+// TODO deprecate in the next major release, use opentracing.Tag instead.
 type Tag struct {
 	key   string
 	value interface{}

tracer.go

@@ -35,7 +35,8 @@ import (
 	"github.com/uber/jaeger-client-go/utils"
 )
 
-type tracer struct {
+// Tracer implements opentracing.Tracer.
+type Tracer struct {
 	serviceName string
 	hostIPv4    uint32 // this is for zipkin endpoint conversion
 
@@ -73,7 +74,7 @@ func NewTracer(
 	reporter Reporter,
 	options ...TracerOption,
 ) (opentracing.Tracer, io.Closer) {
-	t := &tracer{
+	t := &Tracer{
 		serviceName: serviceName,
 		sampler:     sampler,
 		reporter:    reporter,
@@ -138,7 +139,8 @@ func NewTracer(
 	return t, t
 }
 
-func (t *tracer) StartSpan(
+// StartSpan implements StartSpan() method of opentracing.Tracer.
+func (t *Tracer) StartSpan(
 	operationName string,
 	options ...opentracing.StartSpanOption,
 ) opentracing.Span {
@@ -149,7 +151,7 @@ func (t *tracer) StartSpan(
 	return t.startSpanWithOptions(operationName, sso)
 }
 
-func (t *tracer) startSpanWithOptions(
+func (t *Tracer) startSpanWithOptions(
 	operationName string,
 	options opentracing.StartSpanOptions,
 ) opentracing.Span {
@@ -245,7 +247,7 @@ func (t *tracer) startSpanWithOptions(
 }
 
 // Inject implements Inject() method of opentracing.Tracer
-func (t *tracer) Inject(ctx opentracing.SpanContext, format interface{}, carrier interface{}) error {
+func (t *Tracer) Inject(ctx opentracing.SpanContext, format interface{}, carrier interface{}) error {
 	c, ok := ctx.(SpanContext)
 	if !ok {
 		return opentracing.ErrInvalidSpanContext
@@ -257,7 +259,7 @@ func (t *tracer) Inject(ctx opentracing.SpanContext, format interface{}, carrier
 }
 
 // Extract implements Extract() method of opentracing.Tracer
-func (t *tracer) Extract(
+func (t *Tracer) Extract(
 	format interface{},
 	carrier interface{},
 ) (opentracing.SpanContext, error) {
@@ -268,15 +270,24 @@ func (t *tracer) Extract(
 }
 
 // Close releases all resources used by the Tracer and flushes any remaining buffered spans.
-func (t *tracer) Close() error {
+func (t *Tracer) Close() error {
 	t.reporter.Close()
 	t.sampler.Close()
 	return nil
 }
 
+// Tags returns a slice of tracer-level tags.
+func (t *Tracer) Tags() []opentracing.Tag {
+	tags := make([]opentracing.Tag, len(t.tags))
+	for i, tag := range t.tags {
+		tags[i] = opentracing.Tag{Key: tag.key, Value: tag.value}
+	}
+	return tags
+}
+
 // newSpan returns an instance of a clean Span object.
 // If options.PoolSpans is true, the spans are retrieved from an object pool.
-func (t *tracer) newSpan() *Span {
+func (t *Tracer) newSpan() *Span {
 	if !t.options.poolSpans {
 		return &Span{}
 	}
@@ -288,7 +299,7 @@ func (t *tracer) newSpan() *Span {
 	return sp
 }
 
-func (t *tracer) startSpanInternal(
+func (t *Tracer) startSpanInternal(
 	sp *Span,
 	operationName string,
 	startTime time.Time,
@@ -339,7 +350,7 @@ func (t *tracer) startSpanInternal(
 	return sp
 }
 
-func (t *tracer) reportSpan(sp *Span) {
+func (t *Tracer) reportSpan(sp *Span) {
 	t.metrics.SpansFinished.Inc(1)
 	if sp.context.IsSampled() {
 		t.reporter.Report(sp)
@@ -351,7 +362,7 @@ func (t *tracer) reportSpan(sp *Span) {
 
 // randomID generates a random trace/span ID, using tracer.random() generator.
 // It never returns 0.
-func (t *tracer) randomID() uint64 {
+func (t *Tracer) randomID() uint64 {
 	val := t.randomNumber()
 	for val == 0 {
 		val = t.randomNumber()

tracer_options.go

@@ -25,7 +25,7 @@ import (
 )
 
 // TracerOption is a function that sets some option on the tracer
-type TracerOption func(tracer *tracer)
+type TracerOption func(tracer *Tracer)
 
 // TracerOptions is a factory for all available TracerOption's
 var TracerOptions tracerOptions
@@ -35,30 +35,30 @@ type tracerOptions struct{}
 // Metrics creates a TracerOption that initializes Metrics on the tracer,
 // which is used to emit statistics.
 func (tracerOptions) Metrics(m *Metrics) TracerOption {
-	return func(tracer *tracer) {
+	return func(tracer *Tracer) {
 		tracer.metrics = *m
 	}
 }
 
 // Logger creates a TracerOption that gives the tracer a Logger.
 func (tracerOptions) Logger(logger Logger) TracerOption {
-	return func(tracer *tracer) {
+	return func(tracer *Tracer) {
 		tracer.logger = logger
 	}
 }
 
 // TimeNow creates a TracerOption that gives the tracer a function
 // used to generate timestamps for spans.
 func (tracerOptions) TimeNow(timeNow func() time.Time) TracerOption {
-	return func(tracer *tracer) {
+	return func(tracer *Tracer) {
 		tracer.timeNow = timeNow
 	}
 }
 
 // RandomNumber creates a TracerOption that gives the tracer
 // a thread-safe random number generator function for generating trace IDs.
 func (tracerOptions) RandomNumber(randomNumber func() uint64) TracerOption {
-	return func(tracer *tracer) {
+	return func(tracer *Tracer) {
 		tracer.randomNumber = randomNumber
 	}
 }
@@ -68,7 +68,7 @@ func (tracerOptions) RandomNumber(randomNumber func() uint64) TracerOption {
 // This should be used with care, only if the service is not running any async tasks
 // that can access parent spans after those spans have been finished.
 func (tracerOptions) PoolSpans(poolSpans bool) TracerOption {
-	return func(tracer *tracer) {
+	return func(tracer *Tracer) {
 		tracer.options.poolSpans = poolSpans
 	}
 }
@@ -77,31 +77,37 @@ func (tracerOptions) PoolSpans(poolSpans bool) TracerOption {
 // If not set, the factory method will obtain the current IP address.
 // The TracerOption is deprecated; the tracer will attempt to automatically detect the IP.
 func (tracerOptions) HostIPv4(hostIPv4 uint32) TracerOption {
-	return func(tracer *tracer) {
+	return func(tracer *Tracer) {
 		tracer.hostIPv4 = hostIPv4
 	}
 }
 
 func (tracerOptions) Injector(format interface{}, injector Injector) TracerOption {
-	return func(tracer *tracer) {
+	return func(tracer *Tracer) {
 		tracer.injectors[format] = injector
 	}
 }
 
 func (tracerOptions) Extractor(format interface{}, extractor Extractor) TracerOption {
-	return func(tracer *tracer) {
+	return func(tracer *Tracer) {
 		tracer.extractors[format] = extractor
 	}
 }
 
 func (tracerOptions) Observer(observer Observer) TracerOption {
-	return func(tracer *tracer) {
+	return func(tracer *Tracer) {
 		tracer.observer.append(observer)
 	}
 }
 
 func (tracerOptions) ZipkinSharedRPCSpan(zipkinSharedRPCSpan bool) TracerOption {
-	return func(tracer *tracer) {
+	return func(tracer *Tracer) {
 		tracer.options.zipkinSharedRPCSpan = zipkinSharedRPCSpan
 	}
 }
+
+func (tracerOptions) Tag(key string, value interface{}) TracerOption {
+	return func(tracer *Tracer) {
+		tracer.tags = append(tracer.tags, Tag{key: key, value: value})
+	}
+}