[trace] Add logging support to opentracing plugins

go/cmd/vtadmin/main.go

@@ -123,9 +123,10 @@ func main() {
  rootCmd.Flags().Var(&clusterFileConfig, "cluster-config", "path to a yaml cluster configuration. see clusters.example.yaml") // (TODO:@amason) provide example config.
  rootCmd.Flags().Var(&defaultClusterConfig, "cluster-defaults", "default options for all clusters")
 
- rootCmd.Flags().AddGoFlag(flag.Lookup("tracer")) // defined in go/vt/trace
- rootCmd.Flags().AddGoFlag(flag.Lookup("tracing-sampling-type")) // defined in go/vt/trace
- rootCmd.Flags().AddGoFlag(flag.Lookup("tracing-sampling-rate")) // defined in go/vt/trace
+ rootCmd.Flags().AddGoFlag(flag.Lookup("tracer")) // defined in go/vt/trace
+ rootCmd.Flags().AddGoFlag(flag.Lookup("tracing-enable-logging")) // defined in go/vt/trace
+ rootCmd.Flags().AddGoFlag(flag.Lookup("tracing-sampling-type")) // defined in go/vt/trace
+ rootCmd.Flags().AddGoFlag(flag.Lookup("tracing-sampling-rate")) // defined in go/vt/trace
  rootCmd.Flags().BoolVar(&opts.EnableTracing, "grpc-tracing", false, "whether to enable tracing on the gRPC server")
  rootCmd.Flags().BoolVar(&httpOpts.EnableTracing, "http-tracing", false, "whether to enable tracing on the HTTP server")
 

go/trace/logger.go

@@ -0,0 +1,32 @@
+/*
+Copyright 2021 The Vitess 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 trace
+
+import "vitess.io/vitess/go/vt/log"
+
+// traceLogger wraps the standard vitess log package to satisfy the datadog and
+// jaeger logger interfaces.
+type traceLogger struct{}
+
+// Log is part of the ddtrace.Logger interface. Datadog only ever logs errors.
+func (*traceLogger) Log(msg string) { log.Errorf(msg) }
+
+// Error is part of the jaeger.Logger interface.
+func (*traceLogger) Error(msg string) { log.Errorf(msg) }
+
+// Infof is part of the jaeger.Logger interface.
+func (*traceLogger) Infof(msg string, args ...interface{}) { log.Infof(msg, args...) }

go/trace/plugin_datadog.go

@@ -20,12 +20,18 @@ func newDatadogTracer(serviceName string) (tracingService, io.Closer, error) {
  return nil, nil, fmt.Errorf("need host and port to datadog agent to use datadog tracing")
  }
 
- t := opentracer.New(
- ddtracer.WithAgentAddr(*dataDogHost+":"+*dataDogPort),
+ opts := []ddtracer.StartOption{
+ ddtracer.WithAgentAddr(*dataDogHost + ":" + *dataDogPort),
  ddtracer.WithServiceName(serviceName),
  ddtracer.WithDebugMode(true),
  ddtracer.WithSampler(ddtracer.NewRateSampler(samplingRate.Get())),
- )
+ }
+
+ if *enableLogging {
+ opts = append(opts, ddtracer.WithLogger(&traceLogger{}))
+ }
+
+ t := opentracer.New(opts...)
 
  opentracing.SetGlobalTracer(t)
 

go/trace/plugin_jaeger.go

@@ -98,7 +98,14 @@ func newJagerTracerFromEnv(serviceName string) (tracingService, io.Closer, error
 
  log.Infof("Tracing sampler type %v (param: %v)", cfg.Sampler.Type, cfg.Sampler.Param)
 
- tracer, closer, err := cfg.NewTracer()
+ var opts []config.Option
+ if *enableLogging {
+ opts = append(opts, config.Logger(&traceLogger{}))
+ } else if cfg.Reporter.LogSpans {
+ log.Warningf("JAEGER_REPORTER_LOG_SPANS was set, but -tracing-enable-logging was not; spans will not be logged")
+ }
+
+ tracer, closer, err := cfg.NewTracer(opts...)
 
  if err != nil {
  return nil, &nilCloser{}, err

go/trace/trace.go

@@ -133,6 +133,7 @@ var currentTracer tracingService = noopTracingServer{}
 
 var (
  tracingServer = flag.String("tracer", "noop", "tracing service to use")
+ enableLogging = flag.Bool("tracing-enable-logging", false, "whether to enable logging in the tracing service")
 )
 
 // StartTracing enables tracing for a named service