@@ -16,35 +16,74 @@ package trace
1616
1717import (
1818 "context"
19+ "errors"
1920 "fmt"
21+ "os"
22+ "sort"
23+ "strings"
2024
2125 "go.opencensus.io/trace"
22- "golang.org/x/xerrors"
26+ "go.opentelemetry.io/otel"
27+ "go.opentelemetry.io/otel/attribute"
28+ "go.opentelemetry.io/otel/codes"
29+ ottrace "go.opentelemetry.io/otel/trace"
2330 "google.golang.org/api/googleapi"
2431 "google.golang.org/genproto/googleapis/rpc/code"
2532 "google.golang.org/grpc/status"
2633)
2734
35+ const (
36+ telemetryPlatformTracing = "GOOGLE_API_GO_EXPERIMENTAL_TELEMETRY_PLATFORM_TRACING"
37+ telemetryPlatformTracingOpenCensus = "opencensus"
38+ telemetryPlatformTracingOpenTelemetry = "opentelemetry"
39+ )
40+
41+ var (
42+ // TODO(chrisdsmith): What is the correct name for the OpenTelemetry tracer?
43+ OpenTelemetryTracerName string = "cloud.google.com/go/internal/trace"
44+ )
45+
46+ func IsOpenCensusTracingEnabled () bool {
47+ return ! IsOpenTelemetryTracingEnabled ()
48+ }
49+
50+ func IsOpenTelemetryTracingEnabled () bool {
51+ env := strings .TrimSpace (os .Getenv (telemetryPlatformTracing ))
52+ return strings .EqualFold (env , telemetryPlatformTracingOpenTelemetry )
53+ }
54+
2855// StartSpan adds a span to the trace with the given name.
2956func StartSpan (ctx context.Context , name string ) context.Context {
30- ctx , _ = trace .StartSpan (ctx , name )
57+ if IsOpenTelemetryTracingEnabled () {
58+ ctx , _ = otel .GetTracerProvider ().Tracer (OpenTelemetryTracerName ).Start (ctx , name )
59+ } else {
60+ ctx , _ = trace .StartSpan (ctx , name )
61+ }
3162 return ctx
3263}
3364
3465// EndSpan ends a span with the given error.
3566func EndSpan (ctx context.Context , err error ) {
36- span := trace .FromContext (ctx )
37- if err != nil {
38- span .SetStatus (toStatus (err ))
67+ if IsOpenTelemetryTracingEnabled () {
68+ span := ottrace .SpanFromContext (ctx )
69+ if err != nil {
70+ span .SetStatus (codes .Error , toOpenTelemetryStatusDescription (err ))
71+ span .RecordError (err )
72+ }
73+ span .End ()
74+ } else {
75+ span := trace .FromContext (ctx )
76+ if err != nil {
77+ span .SetStatus (toStatus (err ))
78+ }
79+ span .End ()
3980 }
40- span .End ()
4181}
4282
43- // toStatus interrogates an error and converts it to an appropriate
44- // OpenCensus status.
83+ // toStatus converts an error to an equivalent OpenCensus status.
4584func toStatus (err error ) trace.Status {
4685 var err2 * googleapi.Error
47- if ok := xerrors .As (err , & err2 ); ok {
86+ if ok := errors .As (err , & err2 ); ok {
4887 return trace.Status {Code : httpStatusCodeToOCCode (err2 .Code ), Message : err2 .Message }
4988 } else if s , ok := status .FromError (err ); ok {
5089 return trace.Status {Code : int32 (s .Code ()), Message : s .Message ()}
@@ -53,6 +92,18 @@ func toStatus(err error) trace.Status {
5392 }
5493}
5594
95+ // toOpenTelemetryStatus converts an error to an equivalent OpenTelemetry status description.
96+ func toOpenTelemetryStatusDescription (err error ) string {
97+ var err2 * googleapi.Error
98+ if ok := errors .As (err , & err2 ); ok {
99+ return err2 .Message
100+ } else if s , ok := status .FromError (err ); ok {
101+ return s .Message ()
102+ } else {
103+ return err .Error ()
104+ }
105+ }
106+
56107// TODO(deklerk): switch to using OpenCensus function when it becomes available.
57108// Reference: https://github.com/googleapis/googleapis/blob/26b634d2724ac5dd30ae0b0cbfb01f07f2e4050e/google/rpc/code.proto
58109func httpStatusCodeToOCCode (httpStatusCode int ) int32 {
@@ -86,10 +137,25 @@ func httpStatusCodeToOCCode(httpStatusCode int) int32 {
86137 }
87138}
88139
140+ // TracePrintf retrieves the current OpenCensus or OpenTelemetry span from context, then:
141+ // * calls Span.Annotatef if OpenCensus is enabled; or
142+ // * calls Span.AddEvent if OpenTelemetry is enabled.
143+ //
89144// TODO: (odeke-em): perhaps just pass around spans due to the cost
90145// incurred from using trace.FromContext(ctx) yet we could avoid
91146// throwing away the work done by ctx, span := trace.StartSpan.
92147func TracePrintf (ctx context.Context , attrMap map [string ]interface {}, format string , args ... interface {}) {
148+ if IsOpenTelemetryTracingEnabled () {
149+ attrs := otAttrs (attrMap )
150+ ottrace .SpanFromContext (ctx ).AddEvent (fmt .Sprintf (format , args ... ), ottrace .WithAttributes (attrs ... ))
151+ } else {
152+ attrs := ocAttrs (attrMap )
153+ trace .FromContext (ctx ).Annotatef (attrs , format , args ... )
154+ }
155+ }
156+
157+ // ocAttrs converts a generic map to OpenCensus attributes.
158+ func ocAttrs (attrMap map [string ]interface {}) []trace.Attribute {
93159 var attrs []trace.Attribute
94160 for k , v := range attrMap {
95161 var a trace.Attribute
@@ -107,5 +173,34 @@ func TracePrintf(ctx context.Context, attrMap map[string]interface{}, format str
107173 }
108174 attrs = append (attrs , a )
109175 }
110- trace .FromContext (ctx ).Annotatef (attrs , format , args ... )
176+ return attrs
177+ }
178+
179+ // otAttrs converts a generic map to OpenTelemetry attributes.
180+ func otAttrs (attrMap map [string ]interface {}) []attribute.KeyValue {
181+ var attrs []attribute.KeyValue
182+ // Sort the input map by its keys for predictable order in tests.
183+ keys := make ([]string , 0 , len (attrMap ))
184+ for k := range attrMap {
185+ keys = append (keys , k )
186+ }
187+ sort .Strings (keys )
188+ for _ , k := range keys {
189+ v := attrMap [k ]
190+ var a attribute.KeyValue
191+ switch v := v .(type ) {
192+ case string :
193+ a = attribute .Key (k ).String (v )
194+ case bool :
195+ a = attribute .Key (k ).Bool (v )
196+ case int :
197+ a = attribute .Key (k ).Int (v )
198+ case int64 :
199+ a = attribute .Key (k ).Int64 (v )
200+ default :
201+ a = attribute .Key (k ).String (fmt .Sprintf ("%#v" , v ))
202+ }
203+ attrs = append (attrs , a )
204+ }
205+ return attrs
111206}
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