Updates for jaeger tracing client.

vendor/github.com/uber/jaeger-client-go/header.go

@@ -0,0 +1,64 @@
+// Copyright (c) 2017 Uber Technologies, Inc.
+//
+// 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 jaeger
+
+// HeadersConfig contains the values for the header keys that Jaeger will use.
+// These values may be either custom or default depending on whether custom
+// values were provided via a configuration.
+type HeadersConfig struct {
+	// JaegerDebugHeader is the name of HTTP header or a TextMap carrier key which,
+	// if found in the carrier, forces the trace to be sampled as "debug" trace.
+	// The value of the header is recorded as the tag on the root span, so that the
+	// trace can be found in the UI using this value as a correlation ID.
+	JaegerDebugHeader string `yaml:"jaegerDebugHeader"`
+
+	// JaegerBaggageHeader is the name of the HTTP header that is used to submit baggage.
+	// It differs from TraceBaggageHeaderPrefix in that it can be used only in cases where
+	// a root span does not exist.
+	JaegerBaggageHeader string `yaml:"jaegerBaggageHeader"`
+
+	// TraceContextHeaderName is the http header name used to propagate tracing context.
+	// This must be in lower-case to avoid mismatches when decoding incoming headers.
+	TraceContextHeaderName string `yaml:"TraceContextHeaderName"`
+
+	// TraceBaggageHeaderPrefix is the prefix for http headers used to propagate baggage.
+	// This must be in lower-case to avoid mismatches when decoding incoming headers.
+	TraceBaggageHeaderPrefix string `yaml:"traceBaggageHeaderPrefix"`
+}
+
+func (c *HeadersConfig) applyDefaults() *HeadersConfig {
+	if c.JaegerBaggageHeader == "" {
+		c.JaegerBaggageHeader = JaegerBaggageHeader
+	}
+	if c.JaegerDebugHeader == "" {
+		c.JaegerDebugHeader = JaegerDebugHeader
+	}
+	if c.TraceBaggageHeaderPrefix == "" {
+		c.TraceBaggageHeaderPrefix = TraceBaggageHeaderPrefix
+	}
+	if c.TraceContextHeaderName == "" {
+		c.TraceContextHeaderName = TraceContextHeaderName
+	}
+	return c
+}
+
+func getDefaultHeadersConfig() *HeadersConfig {
+	return &HeadersConfig{
+		JaegerDebugHeader:        JaegerDebugHeader,
+		JaegerBaggageHeader:      JaegerBaggageHeader,
+		TraceContextHeaderName:   TraceContextHeaderName,
+		TraceBaggageHeaderPrefix: TraceBaggageHeaderPrefix,
+	}
+}