Merge remote-tracking branch 'upstream/main' into upgrade-hotrod-to-otel

Signed-off-by: Afzal Ansari <afzal442@gmail.com>

examples/hotrod/pkg/tracing/baggage.go

@@ -0,0 +1,44 @@
+// Copyright (c) 2023 The Jaeger Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tracing
+
+import (
+	"context"
+
+	"github.com/opentracing/opentracing-go"
+	"go.opentelemetry.io/otel/baggage"
+)
+
+func BaggageItem(ctx context.Context, key string) string {
+	val := opentracingBaggageItem(ctx, key)
+	if val != "" {
+		return val
+	}
+	return otelBaggageItem(ctx, key)
+}
+
+func opentracingBaggageItem(ctx context.Context, key string) string {
+	span := opentracing.SpanFromContext(ctx)
+	if span == nil {
+		return ""
+	}
+	return span.BaggageItem(key)
+}
+
+func otelBaggageItem(ctx context.Context, key string) string {
+	b := baggage.FromContext(ctx)
+	m := b.Member(key)
+	return m.Value()
+}

examples/memstore-plugin/README.md

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+# memstore-plugin
+
+This package builds a binary that can be used as an example of a sidecar storage plugin.
+
+Note that Jaeger now supports remote storages via gRPC API, so using plugins is discouraged.
+For example, `memorystore` can be used as a remote backend (https://github.com/jaegertracing/jaeger/issues/3835).