Move baggage and propagation to separate packages (open-telemetry#1325)

* Move propagation code to propagation package

* Move baggage code to baggage package

* Update changelog

* Make docs of baggage.Set more clear

Co-authored-by: Tyler Yahn <[email protected]>

Co-authored-by: Tyler Yahn <[email protected]>

CHANGELOG.md

@@ -71,13 +71,13 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 ### Changed
 
 - Set default propagator to no-op propagator. (#1184)
-- The `HTTPSupplier`, `HTTPExtractor`, `HTTPInjector`, and `HTTPPropagator` from the `go.opentelemetry.io/otel/api/propagation` package were replaced with unified `TextMapCarrier` and `TextMapPropagator` in the `go.opentelemetry.io/otel` package. (#1212)
+- The `HTTPSupplier`, `HTTPExtractor`, `HTTPInjector`, and `HTTPPropagator` from the `go.opentelemetry.io/otel/api/propagation` package were replaced with unified `TextMapCarrier` and `TextMapPropagator` in the `go.opentelemetry.io/otel/propagation` package. (#1212) (#1325)
 - The `New` function from the `go.opentelemetry.io/otel/api/propagation` package was replaced with `NewCompositeTextMapPropagator` in the `go.opentelemetry.io/otel` package. (#1212)
 - The status codes of the `go.opentelemetry.io/otel/codes` package have been updated to match the latest OpenTelemetry specification.
    They now are `Unset`, `Error`, and `Ok`.
    They no longer track the gRPC codes. (#1214)
 - The `StatusCode` field of the `SpanData` struct in the `go.opentelemetry.io/otel/sdk/export/trace` package now uses the codes package from this package instead of the gRPC project. (#1214)
-- Move the `go.opentelemetry.io/otel/api/baggage` package into `go.opentelemetry.io/otel/propagators`. (#1217)
+- Move the `go.opentelemetry.io/otel/api/baggage` package into `go.opentelemetry.io/otel/baggage`. (#1217) (#1325)
 - A `Shutdown` method of `SpanProcessor` and all its implementations receives a context and returns an error. (#1264)
 
 ### Fixed

baggage.go → baggage/baggage.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package otel // import "go.opentelemetry.io/otel"
+package baggage // import "go.opentelemetry.io/otel/baggage"
 
 import (
 	"context"
@@ -21,8 +21,8 @@ import (
 	"go.opentelemetry.io/otel/label"
 )
 
-// Baggage returns a copy of the baggage in ctx.
-func Baggage(ctx context.Context) label.Set {
+// Set returns a copy of the set of baggage key-values in ctx.
+func Set(ctx context.Context) label.Set {
 	// TODO (MrAlias, #1222): The underlying storage, the Map, shares many of
 	// the functional elements of the label.Set. These should be unified so
 	// this conversion is unnecessary and there is no performance hit calling
@@ -36,32 +36,32 @@ func Baggage(ctx context.Context) label.Set {
 	return label.NewSet(values...)
 }
 
-// BaggageValue returns the value related to key in the baggage of ctx. If no
+// Value returns the value related to key in the baggage of ctx. If no
 // value is set, the returned label.Value will be an uninitialized zero-value
 // with type INVALID.
-func BaggageValue(ctx context.Context, key label.Key) label.Value {
+func Value(ctx context.Context, key label.Key) label.Value {
 	v, _ := baggage.MapFromContext(ctx).Value(key)
 	return v
 }
 
-// ContextWithBaggageValues returns a copy of parent with pairs updated in the baggage.
-func ContextWithBaggageValues(parent context.Context, pairs ...label.KeyValue) context.Context {
+// ContextWithValues returns a copy of parent with pairs updated in the baggage.
+func ContextWithValues(parent context.Context, pairs ...label.KeyValue) context.Context {
 	m := baggage.MapFromContext(parent).Apply(baggage.MapUpdate{
 		MultiKV: pairs,
 	})
 	return baggage.ContextWithMap(parent, m)
 }
 
-// ContextWithoutBaggageValues returns a copy of parent in which the values related
+// ContextWithoutValues returns a copy of parent in which the values related
 // to keys have been removed from the baggage.
-func ContextWithoutBaggageValues(parent context.Context, keys ...label.Key) context.Context {
+func ContextWithoutValues(parent context.Context, keys ...label.Key) context.Context {
 	m := baggage.MapFromContext(parent).Apply(baggage.MapUpdate{
 		DropMultiK: keys,
 	})
 	return baggage.ContextWithMap(parent, m)
 }
 
-// ContextWithoutBaggage returns a copy of parent without baggage.
-func ContextWithoutBaggage(parent context.Context) context.Context {
+// ContextWithEmpty returns a copy of parent without baggage.
+func ContextWithEmpty(parent context.Context) context.Context {
 	return baggage.ContextWithNoCorrelationData(parent)
 }

baggage_test.go → baggage/baggage_test.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package otel
+package baggage
 
 import (
 	"context"
@@ -26,59 +26,59 @@ func TestBaggage(t *testing.T) {
 	ctx := context.Background()
 	ctx = baggage.ContextWithMap(ctx, baggage.NewEmptyMap())
 
-	b := Baggage(ctx)
+	b := Set(ctx)
 	if b.Len() != 0 {
 		t.Fatalf("empty baggage returned a set with %d elements", b.Len())
 	}
 
 	first, second, third := label.Key("first"), label.Key("second"), label.Key("third")
-	ctx = ContextWithBaggageValues(ctx, first.Bool(true), second.String("2"))
+	ctx = ContextWithValues(ctx, first.Bool(true), second.String("2"))
 	m := baggage.MapFromContext(ctx)
 	v, ok := m.Value(first)
 	if !ok {
-		t.Fatal("WithBaggageValues failed to set first value")
+		t.Fatal("WithValues failed to set first value")
 	}
 	if !v.AsBool() {
-		t.Fatal("WithBaggageValues failed to set first correct value")
+		t.Fatal("WithValues failed to set first correct value")
 	}
 	v, ok = m.Value(second)
 	if !ok {
-		t.Fatal("WithBaggageValues failed to set second value")
+		t.Fatal("WithValues failed to set second value")
 	}
 	if v.AsString() != "2" {
-		t.Fatal("WithBaggageValues failed to set second correct value")
+		t.Fatal("WithValues failed to set second correct value")
 	}
 	_, ok = m.Value(third)
 	if ok {
-		t.Fatal("WithBaggageValues set an unexpected third value")
+		t.Fatal("WithValues set an unexpected third value")
 	}
 
-	b = Baggage(ctx)
+	b = Set(ctx)
 	if b.Len() != 2 {
 		t.Fatalf("Baggage returned a set with %d elements, want 2", b.Len())
 	}
 
-	v = BaggageValue(ctx, first)
+	v = Value(ctx, first)
 	if v.Type() != label.BOOL || !v.AsBool() {
-		t.Fatal("BaggageValue failed to get correct first value")
+		t.Fatal("Value failed to get correct first value")
 	}
-	v = BaggageValue(ctx, second)
+	v = Value(ctx, second)
 	if v.Type() != label.STRING || v.AsString() != "2" {
-		t.Fatal("BaggageValue failed to get correct second value")
+		t.Fatal("Value failed to get correct second value")
 	}
 
-	ctx = ContextWithoutBaggageValues(ctx, first)
+	ctx = ContextWithoutValues(ctx, first)
 	m = baggage.MapFromContext(ctx)
 	_, ok = m.Value(first)
 	if ok {
-		t.Fatal("WithoutBaggageValues failed to remove a baggage value")
+		t.Fatal("WithoutValues failed to remove a baggage value")
 	}
 	_, ok = m.Value(second)
 	if !ok {
-		t.Fatal("WithoutBaggageValues removed incorrect value")
+		t.Fatal("WithoutValues removed incorrect value")
 	}
 
-	ctx = ContextWithoutBaggage(ctx)
+	ctx = ContextWithEmpty(ctx)
 	m = baggage.MapFromContext(ctx)
 	if m.Len() != 0 {
 		t.Fatal("WithoutBaggage failed to clear baggage")

bridge/opentracing/bridge.go

@@ -25,16 +25,15 @@ import (
 	otext "github.com/opentracing/opentracing-go/ext"
 	otlog "github.com/opentracing/opentracing-go/log"
 
-	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/bridge/opentracing/migration"
 	"go.opentelemetry.io/otel/codes"
 	otelglobal "go.opentelemetry.io/otel/global"
 	"go.opentelemetry.io/otel/internal/baggage"
 	"go.opentelemetry.io/otel/internal/trace/noop"
 	otelparent "go.opentelemetry.io/otel/internal/trace/parent"
 	"go.opentelemetry.io/otel/label"
+	"go.opentelemetry.io/otel/propagation"
 	"go.opentelemetry.io/otel/trace"
-
-	"go.opentelemetry.io/otel/bridge/opentracing/migration"
 )
 
 type bridgeSpanContext struct {
@@ -294,7 +293,7 @@ type BridgeTracer struct {
 	warningHandler BridgeWarningHandler
 	warnOnce       sync.Once
 
-	propagator otel.TextMapPropagator
+	propagator propagation.TextMapPropagator
 }
 
 var _ ot.Tracer = &BridgeTracer{}
@@ -329,7 +328,7 @@ func (t *BridgeTracer) SetOpenTelemetryTracer(tracer trace.Tracer) {
 	t.setTracer.isSet = true
 }
 
-func (t *BridgeTracer) SetTextMapPropagator(propagator otel.TextMapPropagator) {
+func (t *BridgeTracer) SetTextMapPropagator(propagator propagation.TextMapPropagator) {
 	t.propagator = propagator
 }
 
@@ -651,7 +650,7 @@ func (t *BridgeTracer) Extract(format interface{}, carrier interface{}) (ot.Span
 	return bridgeSC, nil
 }
 
-func (t *BridgeTracer) getPropagator() otel.TextMapPropagator {
+func (t *BridgeTracer) getPropagator() propagation.TextMapPropagator {
 	if t.propagator != nil {
 		return t.propagator
 	}

example/basic/main.go

@@ -18,12 +18,12 @@ import (
 	"context"
 	"log"
 
-	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/baggage"
 	"go.opentelemetry.io/otel/exporters/stdout"
 	"go.opentelemetry.io/otel/global"
 	"go.opentelemetry.io/otel/label"
 	"go.opentelemetry.io/otel/metric"
-	"go.opentelemetry.io/otel/propagators"
+	"go.opentelemetry.io/otel/propagation"
 	"go.opentelemetry.io/otel/sdk/metric/controller/push"
 	"go.opentelemetry.io/otel/sdk/metric/processor/basic"
 	"go.opentelemetry.io/otel/sdk/metric/selector/simple"
@@ -63,7 +63,7 @@ func main() {
 	global.SetMeterProvider(pusher.MeterProvider())
 
 	// set global propagator to baggage (the default is no-op).
-	global.SetTextMapPropagator(propagators.Baggage{})
+	global.SetTextMapPropagator(propagation.Baggage{})
 	tracer := global.Tracer("ex.com/basic")
 	meter := global.Meter("ex.com/basic")
 
@@ -79,7 +79,7 @@ func main() {
 	valuerecorderTwo := metric.Must(meter).NewFloat64ValueRecorder("ex.com.two")
 
 	ctx := context.Background()
-	ctx = otel.ContextWithBaggageValues(ctx, fooKey.String("foo1"), barKey.String("bar1"))
+	ctx = baggage.ContextWithValues(ctx, fooKey.String("foo1"), barKey.String("bar1"))
 
 	valuerecorder := valuerecorderTwo.Bind(commonLabels...)
 	defer valuerecorder.Unbind()
@@ -94,7 +94,7 @@ func main() {
 
 		meter.RecordBatch(
 			// Note: call-site variables added as context Entries:
-			otel.ContextWithBaggageValues(ctx, anotherKey.String("xyz")),
+			baggage.ContextWithValues(ctx, anotherKey.String("xyz")),
 			commonLabels,
 
 			valuerecorderTwo.Measurement(2.0),

example/namedtracer/main.go

@@ -18,7 +18,7 @@ import (
 	"context"
 	"log"
 
-	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/baggage"
 	"go.opentelemetry.io/otel/example/namedtracer/foo"
 	"go.opentelemetry.io/otel/exporters/stdout"
 	"go.opentelemetry.io/otel/global"
@@ -63,7 +63,7 @@ func main() {
 	tracer := tp.Tracer("example/namedtracer/main")
 	ctx := context.Background()
 	defer func() { _ = tp.Shutdown(ctx) }()
-	ctx = otel.ContextWithBaggageValues(ctx, fooKey.String("foo1"), barKey.String("bar1"))
+	ctx = baggage.ContextWithValues(ctx, fooKey.String("foo1"), barKey.String("bar1"))
 
 	var span trace.Span
 	ctx, span = tracer.Start(ctx, "operation")

example/otel-collector/main.go

@@ -29,7 +29,7 @@ import (
 	"go.opentelemetry.io/otel/global"
 	"go.opentelemetry.io/otel/label"
 	"go.opentelemetry.io/otel/metric"
-	"go.opentelemetry.io/otel/propagators"
+	"go.opentelemetry.io/otel/propagation"
 	"go.opentelemetry.io/otel/sdk/metric/controller/push"
 	"go.opentelemetry.io/otel/sdk/metric/processor/basic"
 	"go.opentelemetry.io/otel/sdk/metric/selector/simple"
@@ -81,7 +81,7 @@ func initProvider() func() {
 	)
 
 	// set global propagator to tracecontext (the default is no-op).
-	global.SetTextMapPropagator(propagators.TraceContext{})
+	global.SetTextMapPropagator(propagation.TraceContext{})
 	global.SetTracerProvider(tracerProvider)
 	global.SetMeterProvider(pusher.MeterProvider())
 	pusher.Start()

global/internal/propagator.go

@@ -18,33 +18,33 @@ import (
 	"context"
 	"sync"
 
-	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/propagation"
 )
 
 // textMapPropagator is a default TextMapPropagator that delegates calls to a
 // registered delegate if one is set, otherwise it defaults to delegating the
-// calls to a the default no-op otel.TextMapPropagator.
+// calls to a the default no-op propagation.TextMapPropagator.
 type textMapPropagator struct {
 	mtx      sync.Mutex
 	once     sync.Once
-	delegate otel.TextMapPropagator
-	noop     otel.TextMapPropagator
+	delegate propagation.TextMapPropagator
+	noop     propagation.TextMapPropagator
 }
 
 // Compile-time guarantee that textMapPropagator implements the
-// otel.TextMapPropagator interface.
-var _ otel.TextMapPropagator = (*textMapPropagator)(nil)
+// propagation.TextMapPropagator interface.
+var _ propagation.TextMapPropagator = (*textMapPropagator)(nil)
 
 func newTextMapPropagator() *textMapPropagator {
 	return &textMapPropagator{
-		noop: otel.NewCompositeTextMapPropagator(),
+		noop: propagation.NewCompositeTextMapPropagator(),
 	}
 }
 
-// SetDelegate sets a delegate otel.TextMapPropagator that all calls are
+// SetDelegate sets a delegate propagation.TextMapPropagator that all calls are
 // forwarded to. Delegation can only be performed once, all subsequent calls
 // perform no delegation.
-func (p *textMapPropagator) SetDelegate(delegate otel.TextMapPropagator) {
+func (p *textMapPropagator) SetDelegate(delegate propagation.TextMapPropagator) {
 	if delegate == nil {
 		return
 	}
@@ -57,7 +57,7 @@ func (p *textMapPropagator) SetDelegate(delegate otel.TextMapPropagator) {
 // effectiveDelegate returns the current delegate of p if one is set,
 // otherwise the default noop TextMapPropagator is returned. This method
 // can be called concurrently.
-func (p *textMapPropagator) effectiveDelegate() otel.TextMapPropagator {
+func (p *textMapPropagator) effectiveDelegate() propagation.TextMapPropagator {
 	p.mtx.Lock()
 	defer p.mtx.Unlock()
 	if p.delegate != nil {
@@ -67,12 +67,12 @@ func (p *textMapPropagator) effectiveDelegate() otel.TextMapPropagator {
 }
 
 // Inject set cross-cutting concerns from the Context into the carrier.
-func (p *textMapPropagator) Inject(ctx context.Context, carrier otel.TextMapCarrier) {
+func (p *textMapPropagator) Inject(ctx context.Context, carrier propagation.TextMapCarrier) {
 	p.effectiveDelegate().Inject(ctx, carrier)
 }
 
 // Extract reads cross-cutting concerns from the carrier into a Context.
-func (p *textMapPropagator) Extract(ctx context.Context, carrier otel.TextMapCarrier) context.Context {
+func (p *textMapPropagator) Extract(ctx context.Context, carrier propagation.TextMapCarrier) context.Context {
 	return p.effectiveDelegate().Extract(ctx, carrier)
 }
 

global/internal/state.go

@@ -18,8 +18,8 @@ import (
 	"sync"
 	"sync/atomic"
 
-	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/metric"
+	"go.opentelemetry.io/otel/propagation"
 	"go.opentelemetry.io/otel/trace"
 )
 
@@ -33,7 +33,7 @@ type (
 	}
 
 	propagatorsHolder struct {
-		tm otel.TextMapPropagator
+		tm propagation.TextMapPropagator
 	}
 )
 
@@ -92,12 +92,12 @@ func SetMeterProvider(mp metric.MeterProvider) {
 }
 
 // TextMapPropagator is the internal implementation for global.TextMapPropagator.
-func TextMapPropagator() otel.TextMapPropagator {
+func TextMapPropagator() propagation.TextMapPropagator {
 	return globalPropagators.Load().(propagatorsHolder).tm
 }
 
 // SetTextMapPropagator is the internal implementation for global.SetTextMapPropagator.
-func SetTextMapPropagator(p otel.TextMapPropagator) {
+func SetTextMapPropagator(p propagation.TextMapPropagator) {
 	// For the textMapPropagator already returned by TextMapPropagator
 	// delegate to p.
 	delegateTextMapPropagatorOnce.Do(func() {