Change BaggageKeyPredicate to filter baggage Members (#5813)

Provide greater flexibility for users when filtering baggage members by
allowing them to inspect the full member.

Author: MrAlias

CHANGELOG.md

@@ -48,6 +48,8 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - Update `go.opentelemetry.io/contrib/config` to latest released configuration schema which introduces breaking changes where `Attributes` is now a `map[string]interface{}`. (#5758)
 - Rename `BaggageKeyPredicate` to `Filter` in `go.opentelemetry.io/contrib/processors/baggage/baggagetrace`. (#5809)
 - Return `*SpanProcessor` from `"go.opentelemetry.io/contrib/processors/baggage/baggagetrace".New` instead of the `trace.SpanProcessor` interface. (#5810)
+- The `Filter` in `go.opentelemetry.io/contrib/processors/baggage/baggagetrace` now accepts a `baggage.Member` as a parameter instead of a string. (#5813)
+- Rename `AllowAllBaggageKeys` to `AllowAllMembers` in `go.opentelemetry.io/contrib/processors/baggage/baggagetrace`. (#5813)
 
 ## [1.27.0/0.52.0/0.21.0/0.7.0/0.2.0] - 2024-05-21
 

processors/baggage/baggagetrace/example_test.go

@@ -8,21 +8,22 @@ import (
 	"strings"
 
 	"go.opentelemetry.io/contrib/processors/baggage/baggagetrace"
+	"go.opentelemetry.io/otel/baggage"
 	"go.opentelemetry.io/otel/sdk/trace"
 )
 
 func ExampleNew_allKeys() {
 	trace.NewTracerProvider(
-		trace.WithSpanProcessor(baggagetrace.New(baggagetrace.AllowAllBaggageKeys)),
+		trace.WithSpanProcessor(baggagetrace.New(baggagetrace.AllowAllMembers)),
 	)
 }
 
 func ExampleNew_keysWithPrefix() {
 	trace.NewTracerProvider(
 		trace.WithSpanProcessor(
 			baggagetrace.New(
-				func(baggageKey string) bool {
-					return strings.HasPrefix(baggageKey, "my-key")
+				func(m baggage.Member) bool {
+					return strings.HasPrefix(m.Key(), "my-key")
 				},
 			),
 		),
@@ -34,8 +35,8 @@ func ExampleNew_keysMatchingRegex() {
 	trace.NewTracerProvider(
 		trace.WithSpanProcessor(
 			baggagetrace.New(
-				func(baggageKey string) bool {
-					return expr.MatchString(baggageKey)
+				func(m baggage.Member) bool {
+					return expr.MatchString(m.Key())
 				},
 			),
 		),

processors/baggage/baggagetrace/processor.go

@@ -11,12 +11,11 @@ import (
 	"go.opentelemetry.io/otel/sdk/trace"
 )
 
-// Filter returns true if the baggage member with key should be added to a
-// span.
-type Filter func(key string) bool
+// Filter returns true if the baggage member should be added to a span.
+type Filter func(member baggage.Member) bool
 
-// AllowAllBaggageKeys allows all baggage members to be added to a span.
-var AllowAllBaggageKeys Filter = func(string) bool { return true }
+// AllowAllMembers allows all baggage members to be added to a span.
+var AllowAllMembers Filter = func(baggage.Member) bool { return true }
 
 // SpanProcessor is a [trace.SpanProcessor] implementation that adds baggage
 // members onto a span as attributes.
@@ -43,12 +42,12 @@ func New(filter Filter) *SpanProcessor {
 func (processor SpanProcessor) OnStart(ctx context.Context, span trace.ReadWriteSpan) {
 	filter := processor.filter
 	if filter == nil {
-		filter = AllowAllBaggageKeys
+		filter = AllowAllMembers
 	}
 
-	for _, entry := range baggage.FromContext(ctx).Members() {
-		if filter(entry.Key()) {
-			span.SetAttributes(attribute.String(entry.Key(), entry.Value()))
+	for _, member := range baggage.FromContext(ctx).Members() {
+		if filter(member) {
+			span.SetAttributes(attribute.String(member.Key(), member.Value()))
 		}
 	}
 }

processors/baggage/baggagetrace/processor_test.go

@@ -44,7 +44,7 @@ func TestSpanProcessorAppendsAllBaggageAttributes(t *testing.T) {
 	// create trace provider with baggage processor and test exporter
 	exporter := NewTestExporter()
 	tp := trace.NewTracerProvider(
-		trace.WithSpanProcessor(New(AllowAllBaggageKeys)),
+		trace.WithSpanProcessor(New(AllowAllMembers)),
 		trace.WithSpanProcessor(trace.NewSimpleSpanProcessor(exporter)),
 	)
 
@@ -65,8 +65,8 @@ func TestSpanProcessorAppendsBaggageAttributesWithHaPrefixPredicate(t *testing.T
 	b = addEntryToBaggage(t, b, "baggage.test", "baggage value")
 	ctx := baggage.ContextWithBaggage(context.Background(), b)
 
-	baggageKeyPredicate := func(key string) bool {
-		return strings.HasPrefix(key, "baggage.")
+	baggageKeyPredicate := func(m baggage.Member) bool {
+		return strings.HasPrefix(m.Key(), "baggage.")
 	}
 
 	// create trace provider with baggage processor and test exporter
@@ -94,8 +94,8 @@ func TestSpanProcessorAppendsBaggageAttributesWithRegexPredicate(t *testing.T) {
 	ctx := baggage.ContextWithBaggage(context.Background(), b)
 
 	expr := regexp.MustCompile(`^baggage\..*`)
-	baggageKeyPredicate := func(key string) bool {
-		return expr.MatchString(key)
+	baggageKeyPredicate := func(m baggage.Member) bool {
+		return expr.MatchString(m.Key())
 	}
 
 	// create trace provider with baggage processor and test exporter
@@ -123,8 +123,8 @@ func TestOnlyAddsBaggageEntriesThatMatchPredicate(t *testing.T) {
 	b = addEntryToBaggage(t, b, "foo", "bar")
 	ctx := baggage.ContextWithBaggage(context.Background(), b)
 
-	baggageKeyPredicate := func(key string) bool {
-		return key == "baggage.test"
+	baggageKeyPredicate := func(m baggage.Member) bool {
+		return m.Key() == "baggage.test"
 	}
 
 	// create trace provider with baggage processor and test exporter