Merge pull request vitessio#5681 from kalfonso/kalfonso.200109-datado…

…g-tracing-plugin

Add datadog plugin for tracing

go.mod

@@ -90,6 +90,7 @@ require (
  google.golang.org/api v0.9.0
  google.golang.org/genproto v0.0.0-20190926190326-7ee9db18f195 // indirect
  google.golang.org/grpc v1.24.0
+ gopkg.in/DataDog/dd-trace-go.v1 v1.17.0
  gopkg.in/asn1-ber.v1 v1.0.0-20150924051756-4e86f4367175 // indirect
  gopkg.in/ldap.v2 v2.5.0
  honnef.co/go/tools v0.0.1-2019.2.3

go.sum

@@ -682,6 +682,7 @@ google.golang.org/grpc v1.21.1 h1:j6XxA85m/6txkUCHvzlV5f+HBNl/1r5cZ2A/3IEFOO8=
 google.golang.org/grpc v1.21.1/go.mod h1:oYelfM1adQP15Ek0mdvEgi9Df8B9CZIaU1084ijfRaM=
 google.golang.org/grpc v1.24.0 h1:vb/1TCsVn3DcJlQ0Gs1yB1pKI6Do2/QNwxdKqmc/b0s=
 google.golang.org/grpc v1.24.0/go.mod h1:XDChyiUovWa60DnaeDeZmSW86xtLtjtZbwvSiRnRtcA=
+gopkg.in/DataDog/dd-trace-go.v1 v1.17.0/go.mod h1:DVp8HmDh8PuTu2Z0fVVlBsyWaC++fzwVCaGWylTe3tg=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6 h1:jMFz6MfLP0/4fUyZle81rXUoxOBFi19VUFKVDOQfozc=
 gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
 gopkg.in/asn1-ber.v1 v1.0.0-20150924051756-4e86f4367175 h1:nn6Zav2sOQHCFJHEspya8KqxhFwKci30UxHy3HXPTyQ=

go/trace/plugin_datadog.go

@@ -0,0 +1,56 @@
+package trace
+
+import (
+ "flag"
+ "fmt"
+ "io"
+
+ "github.com/opentracing/opentracing-go"
+ "gopkg.in/DataDog/dd-trace-go.v1/ddtrace/opentracer"
+ ddtracer "gopkg.in/DataDog/dd-trace-go.v1/ddtrace/tracer"
+)
+
+var (
+ dataDogHost = flag.String("datadog-agent-host", "", "host to send spans to. if empty, no tracing will be done")
+ dataDogPort = flag.String("datadog-agent-port", "", "port to send spans to. if empty, no tracing will be done")
+)
+
+func newDatadogTracer(serviceName string) (tracingService, io.Closer, error) {
+ if *dataDogHost == "" || *dataDogPort == "" {
+ return nil, nil, fmt.Errorf("need host and port to datadog agent to use datadog tracing")
+ }
+
+ t := opentracer.New(
+ ddtracer.WithAgentAddr(*dataDogHost+":"+*dataDogPort),
+ ddtracer.WithServiceName(serviceName),
+ ddtracer.WithDebugMode(true),
+ ddtracer.WithSampler(ddtracer.NewRateSampler(*samplingRate)),
+ )
+
+ opentracing.SetGlobalTracer(t)
+
+ return openTracingService{Tracer: &datadogTracer{actual: t}}, &ddCloser{}, nil
+}
+
+var _ io.Closer = (*ddCloser)(nil)
+
+type ddCloser struct{}
+
+func (ddCloser) Close() error {
+ ddtracer.Stop()
+ return nil
+}
+
+func init() {
+ tracingBackendFactories["opentracing-datadog"] = newDatadogTracer
+}
+
+var _ tracer = (*datadogTracer)(nil)
+
+type datadogTracer struct {
+ actual opentracing.Tracer
+}
+
+func (dt *datadogTracer) GetOpenTracingTracer() opentracing.Tracer {
+ return dt.actual
+}