diff options
| -rw-r--r-- | plugin/trace/README.md | 7 | ||||
| -rw-r--r-- | plugin/trace/trace.go | 10 |
2 files changed, 17 insertions, 0 deletions
diff --git a/plugin/trace/README.md b/plugin/trace/README.md index b6a59fd6c..d0b955409 100644 --- a/plugin/trace/README.md +++ b/plugin/trace/README.md @@ -93,6 +93,13 @@ trace tracinghost:9411 { } ~~~ +## Metadata + +The trace plugin will publish the following metadata, if the *metadata* +plugin is also enabled: + +* `trace/traceid`: identifier of (zipkin/datadog) trace of processed request + ## See Also See the *debug* plugin for more information about debug logging. diff --git a/plugin/trace/trace.go b/plugin/trace/trace.go index 1b74dcbc3..d476d3b3f 100644 --- a/plugin/trace/trace.go +++ b/plugin/trace/trace.go @@ -8,6 +8,7 @@ import ( "sync/atomic" "github.com/coredns/coredns/plugin" + "github.com/coredns/coredns/plugin/metadata" "github.com/coredns/coredns/plugin/pkg/dnstest" "github.com/coredns/coredns/plugin/pkg/log" "github.com/coredns/coredns/plugin/pkg/rcode" @@ -21,6 +22,7 @@ import ( zipkinot "github.com/openzipkin-contrib/zipkin-go-opentracing" "github.com/openzipkin/zipkin-go" zipkinhttp "github.com/openzipkin/zipkin-go/reporter/http" + "gopkg.in/DataDog/dd-trace-go.v1/ddtrace" "gopkg.in/DataDog/dd-trace-go.v1/ddtrace/ext" "gopkg.in/DataDog/dd-trace-go.v1/ddtrace/opentracer" "gopkg.in/DataDog/dd-trace-go.v1/ddtrace/tracer" @@ -28,6 +30,7 @@ import ( const ( defaultTopLevelSpanName = "servedns" + metaTraceIdKey = "trace/traceid" ) type traceTags struct { @@ -141,6 +144,13 @@ func (t *trace) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg) span = t.Tracer().StartSpan(defaultTopLevelSpanName) defer span.Finish() + switch spanCtx := span.Context().(type) { + case zipkinot.SpanContext: + metadata.SetValueFunc(ctx, metaTraceIdKey, func() string{ return spanCtx.TraceID.String() }) + case ddtrace.SpanContext: + metadata.SetValueFunc(ctx, metaTraceIdKey, func() string{ return fmt.Sprint(spanCtx.TraceID()) }) + } + rw := dnstest.NewRecorder(w) ctx = ot.ContextWithSpan(ctx, span) status, err := plugin.NextOrFailure(t.Name(), t.Next, ctx, rw, r) |