Update example to use jaeger exporter and update Readme (#143)

* update http example to use jaeger exporter and sdk.

* update image location.

* remove extra parameters for jaeger.

example/README.md

@@ -0,0 +1,59 @@
+# Example
+
+## HTTP
+This is a simple example that demonstrates tracing http request from client to server. The example
+shows key aspects of tracing such as 
+- Root Span (on Client)
+- Child Span (on Client)
+- Child Span from a Remote Parent (on Server)
+- SpanContext Propagation (from Client to Server)
+- Span Events
+- Span Attributes
+
+Example uses
+- open-telemetry SDK as trace instrumentation provider,
+- httptrace plugin to facilitate tracing http request on client and server
+- http trace_context propagation to propagate SpanContext on the wire.
+- jaeger exporter to export spans to visualize and store them.
+
+### How to run?
+
+#### Prequisites
+
+- go 1.12 installed 
+- GOPATH is configured.
+
+#### 1 Download git repo
+```
+GO111MODULE="" go get -d go.opentelemetry.io
+```
+
+#### 2 Start All-in-one Jaeger
+
+```
+docker run -d --name jaeger \
+  -p 16686:16686 \
+  -p 14268:14268 \
+  jaegertracing/all-in-one:1.8
+```
+
+#### 3 Start Server
+```
+cd $GOPATH/src/go.opentelemetry.io/example/http/
+go run ./server/server.go
+``` 
+
+#### 4 Start Client
+```
+cd $GOPATH/src/go.opentelemetry.io/example/http/
+go run ./client/client.go
+``` 
+
+#### 5 Check traces on Jaeger UI
+
+Visit http://localhost:16686 with a web browser
+Click on 'Find' to see traces.
+
+[Sample Snapshot](http/images/JaegarTraceExample.png)
+
+

example/http/client/client.go

@@ -18,27 +18,49 @@ import (
 	"context"
 	"fmt"
 	"io/ioutil"
+	"log"
+
 	"net/http"
+	"time"
 
 	"google.golang.org/grpc/codes"
 
 	"go.opentelemetry.io/api/key"
 	"go.opentelemetry.io/api/tag"
 	"go.opentelemetry.io/api/trace"
+	"go.opentelemetry.io/exporter/trace/jaeger"
 	"go.opentelemetry.io/plugin/httptrace"
+	sdktrace "go.opentelemetry.io/sdk/trace"
 )
 
-var (
-	tracer = trace.GlobalTracer().
-		WithService("client").
-		WithComponent("main").
-		WithResources(
-			key.New("whatevs").String("yesss"),
-		)
-)
+func initTracer() {
+	// Register SDK as trace provider.
+	sdktrace.Register()
+
+	// Create Jaeger exporter to be able to retrieve
+	// the collected spans.
+	exporter, err := jaeger.NewExporter(jaeger.Options{
+		CollectorEndpoint: "http://localhost:14268/api/traces",
+		Process: jaeger.Process{
+			ServiceName: "trace-demo",
+		},
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Wrap Jaeger exporter with SimpleSpanProcessor and register the processor.
+	ssp := sdktrace.NewSimpleSpanProcessor(exporter)
+	sdktrace.RegisterSpanProcessor(ssp)
+
+	// For the demonstration, use sdktrace.AlwaysSample sampler to sample all traces.
+	// In a production application, use sdktrace.ProbabilitySampler with a desired probability.
+	sdktrace.ApplyConfig(sdktrace.Config{DefaultSampler: sdktrace.AlwaysSample()})
+}
 
 func main() {
-	fmt.Printf("Tracer %v\n", tracer)
+	initTracer()
+
 	client := http.DefaultClient
 	ctx := tag.NewContext(context.Background(),
 		tag.Insert(key.New("username").String("donuts")),
@@ -46,13 +68,14 @@ func main() {
 
 	var body []byte
 
-	err := tracer.WithSpan(ctx, "say hello",
+	err := trace.GlobalTracer().WithSpan(ctx, "say hello",
 		func(ctx context.Context) error {
 			req, _ := http.NewRequest("GET", "http://localhost:7777/hello", nil)
 
 			ctx, req = httptrace.W3C(ctx, req)
 			httptrace.Inject(ctx, req)
 
+			fmt.Printf("Sending request...\n")
 			res, err := client.Do(req)
 			if err != nil {
 				panic(err)
@@ -68,5 +91,8 @@ func main() {
 		panic(err)
 	}
 
-	fmt.Printf("%s", body)
+	fmt.Printf("Response Received: %s\n\n\n", body)
+	fmt.Printf("Waiting for few seconds to export spans ...\n\n")
+	time.Sleep(10 * time.Second)
+	fmt.Printf("Check traces on http://localhost:16686\n")
 }

example/http/go.sum

@@ -4,6 +4,7 @@ cloud.google.com/go v0.38.0/go.mod h1:990N+gfupTy94rShfmMCWGDn0LpTmnzTp2qbd1dvSR
 github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
 github.com/OpenPeeDeeP/depguard v1.0.0/go.mod h1:7/4sitnI9YlQgTLLk734QlzXT8DuHVnAyztLplQjk+o=
 github.com/StackExchange/wmi v0.0.0-20180116203802-5d049714c4a6/go.mod h1:3eOhrUMpNV+6aFIbp5/iudMxNCF27Vw2OZgy4xEx0Fg=
+github.com/apache/thrift v0.12.0 h1:pODnxUFNcjP9UTLZGTdeh+j16A8lJbRvD3rOtrk/7bs=
 github.com/apache/thrift v0.12.0/go.mod h1:cp2SuWMxlEZw2r+iP2GNCdIi4C1qmUzdZFSVb+bacwQ=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -64,6 +65,7 @@ github.com/googleapis/gax-go/v2 v2.0.5/go.mod h1:DWXyrwAJ9X0FpwwEdw+IPEYBICEFu5m
 github.com/gostaticanalysis/analysisutil v0.0.0-20190318220348-4088753ea4d3/go.mod h1:eEOZF4jCKGi+aprrirO9e7WKB3beBRtWgqGunKl6pKE=
 github.com/hashicorp/golang-lru v0.5.0/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
 github.com/hashicorp/golang-lru v0.5.1/go.mod h1:/m3WP610KZHVQ1SGc6re/UDhFvYD7pJ4Ao+sR/qLZy8=
+github.com/hashicorp/golang-lru v0.5.3 h1:YPkqC67at8FYaadspW/6uE0COsBxS2656RLEr8Bppgk=
 github.com/hashicorp/golang-lru v0.5.3/go.mod h1:iADmTwqILo4mZ8BN3D2Q6+9jd8WM5uGBxy+E8yxSoD4=
 github.com/hashicorp/hcl v0.0.0-20180404174102-ef8a98b0bbce/go.mod h1:oZtUIOe8dh44I2q6ScRibXws4Ajl+d+nod3AaR9vL5w=
 github.com/hpcloud/tail v1.0.0 h1:nfCOvKYfkgYP8hkirhJocXT2+zOD8yUNjXaWfTlyFKI=
@@ -188,6 +190,7 @@ golang.org/x/tools v0.0.0-20190909030654-5b82db07426d/go.mod h1:b+2E5dAYhXwXZwtn
 golang.org/x/tools v0.0.0-20190920225731-5eefd052ad72/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/api v0.4.0/go.mod h1:8k5glujaEP+g9n7WNsDg8QP6cUVNI86fCNMcbazEtwE=
+google.golang.org/api v0.9.0 h1:jbyannxz0XFD3zdjgrSUsaJbgpH4eTrkdhRChkHPfO8=
 google.golang.org/api v0.9.0/go.mod h1:o4eAsZoiT+ibD93RtjEohWalFOjRDx6CVaqeizhEnKg=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
 google.golang.org/appengine v1.4.0/go.mod h1:xpcJRLb0r/rnEns0DIKYYv+WjYCduHsrkT7/EB5XEv4=

example/http/server/server.go

@@ -16,24 +16,43 @@ package main
 
 import (
 	"io"
+	"log"
 	"net/http"
 
-	"go.opentelemetry.io/api/key"
 	"go.opentelemetry.io/api/tag"
 	"go.opentelemetry.io/api/trace"
+	"go.opentelemetry.io/exporter/trace/jaeger"
 	"go.opentelemetry.io/plugin/httptrace"
+	sdktrace "go.opentelemetry.io/sdk/trace"
 )
 
-var (
-	tracer = trace.GlobalTracer().
-		WithService("server").
-		WithComponent("main").
-		WithResources(
-			key.New("whatevs").String("nooooo"),
-		)
-)
+func initTracer() {
+	sdktrace.Register()
+
+	// Create Jaeger exporter to be able to retrieve
+	// the collected spans.
+	exporter, err := jaeger.NewExporter(jaeger.Options{
+		CollectorEndpoint: "http://localhost:14268/api/traces",
+		Process: jaeger.Process{
+			ServiceName: "trace-demo",
+		},
+	})
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Wrap Jaeger exporter with SimpleSpanProcessor and register the processor.
+	ssp := sdktrace.NewSimpleSpanProcessor(exporter)
+	sdktrace.RegisterSpanProcessor(ssp)
+
+	// For the demonstration, use sdktrace.AlwaysSample sampler to sample all traces.
+	// In a production application, use sdktrace.ProbabilitySampler with a desired probability.
+	sdktrace.ApplyConfig(sdktrace.Config{DefaultSampler: sdktrace.AlwaysSample()})
+}
 
 func main() {
+	initTracer()
+
 	helloHandler := func(w http.ResponseWriter, req *http.Request) {
 		attrs, tags, spanCtx := httptrace.Extract(req.Context(), req)
 
@@ -41,7 +60,7 @@ func main() {
 			MultiKV: tags,
 		})))
 
-		ctx, span := tracer.Start(
+		ctx, span := trace.GlobalTracer().Start(
 			req.Context(),
 			"hello",
 			trace.WithAttributes(attrs...),

exporter/trace/jaeger/jaeger.go

@@ -22,13 +22,12 @@ import (
 	"io/ioutil"
 	"log"
 	"net/http"
-	"time"
-
-	"google.golang.org/grpc/codes"
 
 	"github.com/apache/thrift/lib/go/thrift"
 	"google.golang.org/api/support/bundler"
+	"google.golang.org/grpc/codes"
 
+	"go.opentelemetry.io/api/core"
 	gen "go.opentelemetry.io/exporter/trace/jaeger/internal/gen-go/jaeger"
 	"go.opentelemetry.io/sdk/trace"
 )
@@ -165,38 +164,33 @@ func (e *Exporter) ExportSpan(data *trace.SpanData) {
 
 func spanDataToThrift(data *trace.SpanData) *gen.Span {
 	tags := make([]*gen.Tag, 0, len(data.Attributes))
-	for k, v := range data.Attributes {
-		tag := attributeToTag(k, v)
-		if tag != nil {
-			tags = append(tags, tag)
-		}
+	for _, kv := range data.Attributes {
+		tag := coreAttributeToTag(kv)
+		tags = append(tags, tag)
 	}
 
-	tags = append(tags,
-		attributeToTag("status.code", int32(data.Status)),
-		attributeToTag("status.message", data.Status.String()),
+	tags = append(tags, getInt64Tag("status.code", int64(data.Status)),
+		getStringTag("status.message", data.Status.String()),
 	)
 
 	// Ensure that if Status.Code is not OK, that we set the "error" tag on the Jaeger span.
 	// See Issue https://github.com/census-instrumentation/opencensus-go/issues/1041
 	if data.Status != codes.OK {
-		tags = append(tags, attributeToTag("error", true))
+		tags = append(tags, getBoolTag("error", true))
 	}
 
 	var logs []*gen.Log
 	for _, a := range data.MessageEvents {
 		fields := make([]*gen.Tag, 0, len(a.Attributes))
 		for _, kv := range a.Attributes {
-			tag := attributeToTag(kv.Key.Name, kv.Value.Emit())
+			tag := coreAttributeToTag(kv)
 			if tag != nil {
 				fields = append(fields, tag)
 			}
 		}
-		fields = append(fields, attributeToTag("message", a.Message))
+		fields = append(fields, getStringTag("message", a.Message))
 		logs = append(logs, &gen.Log{
-			//Timestamp: a.Time.UnixNano() / 1000,
-			//TODO: [rghetia] update when time is supported in the event.
-			Timestamp: time.Now().UnixNano() / 1000,
+			Timestamp: a.Time.UnixNano() / 1000,
 			Fields:    fields,
 		})
 	}
@@ -227,6 +221,61 @@ func spanDataToThrift(data *trace.SpanData) *gen.Span {
 	}
 }
 
+func coreAttributeToTag(kv core.KeyValue) *gen.Tag {
+	var tag *gen.Tag
+	switch kv.Value.Type {
+	case core.STRING:
+		tag = &gen.Tag{
+			Key:   kv.Key.Name,
+			VStr:  &kv.Value.String,
+			VType: gen.TagType_STRING,
+		}
+	case core.BOOL:
+		tag = &gen.Tag{
+			Key:   kv.Key.Name,
+			VBool: &kv.Value.Bool,
+			VType: gen.TagType_BOOL,
+		}
+	case core.INT32, core.INT64:
+		tag = &gen.Tag{
+			Key:   kv.Key.Name,
+			VLong: &kv.Value.Int64,
+			VType: gen.TagType_LONG,
+		}
+	case core.FLOAT32, core.FLOAT64:
+		tag = &gen.Tag{
+			Key:     kv.Key.Name,
+			VDouble: &kv.Value.Float64,
+			VType:   gen.TagType_DOUBLE,
+		}
+	}
+	return tag
+}
+
+func getInt64Tag(k string, i int64) *gen.Tag {
+	return &gen.Tag{
+		Key:   k,
+		VLong: &i,
+		VType: gen.TagType_LONG,
+	}
+}
+
+func getStringTag(k, s string) *gen.Tag {
+	return &gen.Tag{
+		Key:   k,
+		VStr:  &s,
+		VType: gen.TagType_STRING,
+	}
+}
+
+func getBoolTag(k string, b bool) *gen.Tag {
+	return &gen.Tag{
+		Key:   k,
+		VBool: &b,
+		VType: gen.TagType_BOOL,
+	}
+}
+
 // TODO(rghetia): remove interface{}. see https://github.com/open-telemetry/opentelemetry-go/pull/112/files#r321444786
 func attributeToTag(key string, a interface{}) *gen.Tag {
 	var tag *gen.Tag

exporter/trace/jaeger/jaeger_test.go

@@ -55,9 +55,15 @@ func Test_spanDataToThrift(t *testing.T) {
 				Name:      "/foo",
 				StartTime: now,
 				EndTime:   now,
-				Attributes: map[string]interface{}{
-					"double": doubleValue,
-					"key":    keyValue,
+				Attributes: []core.KeyValue{
+					{
+						Key:   core.Key{Name: "key"},
+						Value: core.Value{Type: core.STRING, String: keyValue},
+					},
+					{
+						Key:   core.Key{Name: "double"},
+						Value: core.Value{Type: core.FLOAT64, Float64: doubleValue},
+					},
 				},
 				// TODO: [rghetia] add events test after event is concrete type.
 				Status: codes.Unknown,

sdk/trace/export.go

@@ -86,7 +86,7 @@ type SpanData struct {
 	// from StartTime by the duration of the span.
 	EndTime time.Time
 	// The values of Attributes each have type string, bool, or int64.
-	Attributes               map[string]interface{}
+	Attributes               []core.KeyValue
 	MessageEvents            []Event
 	Links                    []apitrace.Link
 	Status                   codes.Code

sdk/trace/span.go

@@ -272,13 +272,14 @@ func (s *span) interfaceArrayToMessageEventArray() []Event {
 	return messageEventArr
 }
 
-func (s *span) lruAttributesToAttributeMap() map[string]interface{} {
-	attributes := make(map[string]interface{})
+func (s *span) lruAttributesToAttributeMap() []core.KeyValue {
+	attributes := make([]core.KeyValue, 0, s.lruAttributes.simpleLruMap.Len())
 	for _, key := range s.lruAttributes.simpleLruMap.Keys() {
 		value, ok := s.lruAttributes.simpleLruMap.Get(key)
 		if ok {
 			key := key.(core.Key)
-			attributes[key.Name] = value
+			value := value.(core.Value)
+			attributes = append(attributes, core.KeyValue{Key: key, Value: value})
 		}
 	}
 	return attributes

sdk/trace/trace_test.go

@@ -186,9 +186,12 @@ func TestSetSpanAttributes(t *testing.T) {
 			TraceID:      tid,
 			TraceOptions: 0x1,
 		},
-		ParentSpanID:    sid,
-		Name:            "span0",
-		Attributes:      map[string]interface{}{"key1": core.Value{Type: core.STRING, String: "value1"}},
+		ParentSpanID: sid,
+		Name:         "span0",
+		Attributes: []core.KeyValue{{
+			Key:   core.Key{Name: "key1"},
+			Value: core.Value{Type: core.STRING, String: "value1"},
+		}},
 		HasRemoteParent: true,
 	}
 	if diff := cmp.Diff(got, want); diff != "" {
@@ -217,9 +220,16 @@ func TestSetSpanAttributesOverLimit(t *testing.T) {
 		},
 		ParentSpanID: sid,
 		Name:         "span0",
-		Attributes: map[string]interface{}{
-			"key1": core.Value{Type: core.STRING, String: "value3"},
-			"key4": core.Value{Type: core.STRING, String: "value4"}},
+		Attributes: []core.KeyValue{
+			{
+				Key:   core.Key{Name: "key1"},
+				Value: core.Value{Type: core.STRING, String: "value3"},
+			},
+			{
+				Key:   core.Key{Name: "key4"},
+				Value: core.Value{Type: core.STRING, String: "value4"},
+			},
+		},
 		HasRemoteParent:       true,
 		DroppedAttributeCount: 1,
 	}