Implemented logic for Opentracing baggage propagation

propagators/ot/go.mod

@@ -7,4 +7,5 @@ require (
 	github.com/stretchr/testify v1.7.0
 	go.opentelemetry.io/otel v1.4.1
 	go.opentelemetry.io/otel/trace v1.4.1
+	go.uber.org/multierr v1.8.0
 )

propagators/ot/go.sum

@@ -1,5 +1,6 @@
-github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/go-logr/logr v1.2.2 h1:ahHml/yUpnlb96Rp8HCvtYVPY8ZYpxq3g7UYchIYwbs=
 github.com/go-logr/logr v1.2.2/go.mod h1:jdQByPbusPIv2/zmleS9BjJVeZ6kBagPoEUsqbVz/1A=
 github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
@@ -9,15 +10,21 @@ github.com/google/go-cmp v0.5.7/go.mod h1:n+brtR0CgQNWTVd5ZUFpTBC8YFBDLK/h/bpaJ8
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.7.0 h1:nwc3DEeHmmLAfoZucVR881uASk0Mfjw8xYJ99tb5CcY=
 github.com/stretchr/testify v1.7.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
 go.opentelemetry.io/otel v1.4.1 h1:QbINgGDDcoQUoMJa2mMaWno49lja9sHwp6aoa2n3a4g=
 go.opentelemetry.io/otel v1.4.1/go.mod h1:StM6F/0fSwpd8dKWDCdRr7uRvEPYdW0hBSlbdTiUde4=
 go.opentelemetry.io/otel/trace v1.4.1 h1:O+16qcdTrT7zxv2J6GejTPFinSwA++cYerC5iSiF8EQ=
 go.opentelemetry.io/otel/trace v1.4.1/go.mod h1:iYEVbroFCNut9QkwEczV9vMRPHNKSSwYZjulEtsmhFc=
+go.uber.org/atomic v1.7.0 h1:ADUqmZGgLDDfbSL9ZmPxKTybcoEYHgpYfELNoN+7hsw=
+go.uber.org/atomic v1.7.0/go.mod h1:fEN4uk6kAWBTFdckzkM89CLk9XfWZrxpCo0nPH17wJc=
+go.uber.org/multierr v1.8.0 h1:dg6GjLku4EH+249NNmoIciG9N/jURbDG+pFlTkhzIC8=
+go.uber.org/multierr v1.8.0/go.mod h1:7EAYxJLBy9rStEaz58O2t4Uvip6FSURkq8/ppBp95ak=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543 h1:E7g+9GITq07hpfrRu66IVDexMakfv52eLZ2CXBWiKr4=
 golang.org/x/xerrors v0.0.0-20191204190536-9bdfabe68543/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
+gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b h1:h8qDotaEPuJATrMmW04NCwg7v22aHH28wwpauUhK9Oo=
+gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

propagators/ot/ot_data_test.go

@@ -15,6 +15,8 @@
 package ot_test
 
 import (
+	"strings"
+
 	"go.opentelemetry.io/otel/trace"
 )
 
@@ -38,11 +40,13 @@ var (
 	traceID32    = trace.TraceID{0xa1, 0xce, 0x92, 0x9d, 0x0e, 0x0e, 0x47, 0x36, 0xa3, 0xce, 0x92, 0x9d, 0x0e, 0x0e, 0x47, 0x36}
 	spanID       = trace.SpanID{0x00, 0xf0, 0x67, 0xaa, 0x0b, 0xa9, 0x02, 0xb7}
 	emptyBaggage = map[string]string{}
-	// TODO: once baggage extraction is supported, re-enable this
-	// baggageSet   = attribute.NewSet(
-	// 	attribute.String(baggageKey, baggageValue),
-	// 	attribute.String(baggageKey2, baggageValue2),
-	// )
+	baggageSet   = map[string]string{
+		baggageKey: baggageValue,
+	}
+	baggageSet2 = map[string]string{
+		baggageKey:  baggageValue,
+		baggageKey2: baggageValue2,
+	}
 )
 
 type extractTest struct {
@@ -85,9 +89,22 @@ var extractHeaders = []extractTest{
 			SpanID:     spanID,
 			TraceFlags: trace.FlagsSampled,
 		},
-		emptyBaggage,
-		// TODO: once baggage extraction is supported, re-enable this
-		// &baggageSet,
+		baggageSet,
+	},
+	{
+		"baggage multiple values",
+		map[string]string{
+			traceIDHeader:  traceID32Str,
+			spanIDHeader:   spanIDStr,
+			sampledHeader:  "0",
+			baggageHeader:  baggageValue,
+			baggageHeader2: baggageValue2,
+		},
+		trace.SpanContextConfig{
+			TraceID: traceID32,
+			SpanID:  spanID,
+		},
+		baggageSet2,
 	},
 	{
 		"left padding 64 bit trace ID",
@@ -168,6 +185,48 @@ var invalidExtractHeaders = []extractTest{
 			sampledHeader: "wired",
 		},
 	},
+	{
+		name: "invalid baggage key",
+		headers: map[string]string{
+			traceIDHeader:     traceID32Str,
+			spanIDHeader:      spanIDStr,
+			sampledHeader:     "1",
+			"ot-baggage-d–76": "test",
+		},
+		expected: trace.SpanContextConfig{
+			TraceID:    traceID32,
+			SpanID:     spanID,
+			TraceFlags: trace.FlagsSampled,
+		},
+	},
+	{
+		name: "invalid baggage value",
+		headers: map[string]string{
+			traceIDHeader: traceID32Str,
+			spanIDHeader:  spanIDStr,
+			sampledHeader: "1",
+			baggageHeader: "øtel",
+		},
+		expected: trace.SpanContextConfig{
+			TraceID:    traceID32,
+			SpanID:     spanID,
+			TraceFlags: trace.FlagsSampled,
+		},
+	},
+	{
+		name: "invalid baggage result (too large)",
+		headers: map[string]string{
+			traceIDHeader: traceID32Str,
+			spanIDHeader:  spanIDStr,
+			sampledHeader: "1",
+			baggageHeader: strings.Repeat("s", 8188),
+		},
+		expected: trace.SpanContextConfig{
+			TraceID:    traceID32,
+			SpanID:     spanID,
+			TraceFlags: trace.FlagsSampled,
+		},
+	},
 	{
 		name:    "missing headers",
 		headers: map[string]string{},

propagators/ot/ot_propagator.go

@@ -20,6 +20,8 @@ import (
 	"fmt"
 	"strings"
 
+	"go.uber.org/multierr"
+
 	"go.opentelemetry.io/otel/baggage"
 
 	"go.opentelemetry.io/otel/propagation"
@@ -28,9 +30,10 @@ import (
 
 const (
 	// Default OT Header names.
-	traceIDHeader = "ot-tracer-traceid"
-	spanIDHeader  = "ot-tracer-spanid"
-	sampledHeader = "ot-tracer-sampled"
+	traceIDHeader       = "ot-tracer-traceid"
+	spanIDHeader        = "ot-tracer-spanid"
+	sampledHeader       = "ot-tracer-sampled"
+	baggageHeaderPrefix = "ot-baggage-"
 
 	otTraceIDPadding = "0000000000000000"
 
@@ -72,7 +75,7 @@ func (o OT) Inject(ctx context.Context, carrier propagation.TextMapCarrier) {
 	}
 
 	for _, m := range baggage.FromContext(ctx).Members() {
-		carrier.Set(fmt.Sprintf("ot-baggage-%s", m.Key()), m.Value())
+		carrier.Set(fmt.Sprintf("%s%s", baggageHeaderPrefix, m.Key()), m.Value())
 	}
 
 }
@@ -93,18 +96,43 @@ func (o OT) Extract(ctx context.Context, carrier propagation.TextMapCarrier) con
 	if err != nil || !sc.IsValid() {
 		return ctx
 	}
-	// TODO: implement extracting baggage
-	//
-	// this currently is not achievable without an implementation of `keys`
-	// on the carrier, see:
-	// https://github.com/open-telemetry/opentelemetry-go/issues/1493
+
+	bags, err := extractBags(carrier)
+	if err != nil {
+		return trace.ContextWithRemoteSpanContext(ctx, sc)
+	}
+	ctx = baggage.ContextWithBaggage(ctx, bags)
 	return trace.ContextWithRemoteSpanContext(ctx, sc)
 }
 
 func (o OT) Fields() []string {
 	return []string{traceIDHeader, spanIDHeader, sampledHeader}
 }
 
+// extractBags extracts OpenTracing baggage information from carrier.
+func extractBags(carrier propagation.TextMapCarrier) (baggage.Baggage, error) {
+	var err error
+	var members []baggage.Member
+	for _, key := range carrier.Keys() {
+		lowerKey := strings.ToLower(key)
+		if !strings.HasPrefix(lowerKey, baggageHeaderPrefix) {
+			continue
+		}
+		strippedKey := strings.TrimPrefix(lowerKey, baggageHeaderPrefix)
+		member, e := baggage.NewMember(strippedKey, carrier.Get(key))
+		if e != nil {
+			err = multierr.Append(err, e)
+			continue
+		}
+		members = append(members, member)
+	}
+	bags, e := baggage.New(members...)
+	if err != nil {
+		return bags, multierr.Append(err, e)
+	}
+	return bags, err
+}
+
 // extract reconstructs a SpanContext from header values based on OT
 // headers.
 func extract(traceID, spanID, sampled string) (trace.SpanContext, error) {