42 lines
1.8 KiB
Go
42 lines
1.8 KiB
Go
// Copyright 2017 Michal Witkowski. All Rights Reserved.
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// See LICENSE for licensing terms.
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package grpc_opentracing
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import (
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"strings"
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"github.com/grpc-ecosystem/go-grpc-middleware/tags"
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"github.com/opentracing/opentracing-go"
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"google.golang.org/grpc/grpclog"
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)
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const (
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TagTraceId = "trace.traceid"
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TagSpanId = "trace.spanid"
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)
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// hackyInjectOpentracingIdsToTags writes the given context to the ctxtags.
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// This is done in an incredibly hacky way, because the public-facing interface of opentracing doesn't give access to
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// the TraceId and SpanId of the SpanContext. Only the Tracer's Inject/Extract methods know what these are.
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// Most tracers have them encoded as keys with 'traceid' and 'spanid':
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// https://github.com/openzipkin/zipkin-go-opentracing/blob/594640b9ef7e5c994e8d9499359d693c032d738c/propagation_ot.go#L29
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// https://github.com/opentracing/basictracer-go/blob/1b32af207119a14b1b231d451df3ed04a72efebf/propagation_ot.go#L26
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func hackyInjectOpentracingIdsToTags(span opentracing.Span, tags grpc_ctxtags.Tags) {
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if err := span.Tracer().Inject(span.Context(), opentracing.HTTPHeaders, &hackyTagsCarrier{tags}); err != nil {
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grpclog.Printf("grpc_opentracing: failed extracting trace info into ctx %v", err)
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}
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}
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// hackyTagsCarrier is a really hacky way of
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type hackyTagsCarrier struct {
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grpc_ctxtags.Tags
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}
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func (t *hackyTagsCarrier) Set(key, val string) {
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if strings.Contains(key, "traceid") || strings.Contains(strings.ToLower(key), "traceid") {
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t.Tags.Set(TagTraceId, val) // this will most likely be base-16 (hex) encoded
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} else if (strings.Contains(key, "spanid") && !strings.Contains(key, "parent")) || (strings.Contains(strings.ToLower(key), "spanid") && !strings.Contains(strings.ToLower(key), "parent")) {
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t.Tags.Set(TagSpanId, val) // this will most likely be base-16 (hex) encoded
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}
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}
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