1 package zipkin 2 3 import ( 4 "net/http" 5 6 "github.com/go-kit/log" 7 ) 8 9 // TracerOption allows for functional options to our Zipkin tracing middleware. 10 type TracerOption func(o *tracerOptions) 11 12 // Name sets the name for an instrumented transport endpoint. If name is omitted 13 // at tracing middleware creation, the method of the transport or transport rpc 14 // name is used. 15 func Name(name string) TracerOption { 16 return func(o *tracerOptions) { 17 o.name = name 18 } 19 } 20 21 // Tags adds default tags to our Zipkin transport spans. 22 func Tags(tags map[string]string) TracerOption { 23 return func(o *tracerOptions) { 24 for k, v := range tags { 25 o.tags[k] = v 26 } 27 } 28 } 29 30 // Logger adds a Go kit logger to our Zipkin Middleware to log SpanContext 31 // extract / inject errors if they occur. Default is Noop. 32 func Logger(logger log.Logger) TracerOption { 33 return func(o *tracerOptions) { 34 if logger != nil { 35 o.logger = logger 36 } 37 } 38 } 39 40 // AllowPropagation instructs the tracer to allow or deny propagation of the 41 // span context between this instrumented client or service and its peers. If 42 // the instrumented client connects to services outside its own platform or if 43 // the instrumented service receives requests from untrusted clients it is 44 // strongly advised to disallow propagation. Propagation between services inside 45 // your own platform benefit from propagation. Default for both TraceClient and 46 // TraceServer is to allow propagation. 47 func AllowPropagation(propagate bool) TracerOption { 48 return func(o *tracerOptions) { 49 o.propagate = propagate 50 } 51 } 52 53 // RequestSampler allows one to set the sampling decision based on the details 54 // found in the http.Request. 55 func RequestSampler(sampleFunc func(r *http.Request) bool) TracerOption { 56 return func(o *tracerOptions) { 57 o.requestSampler = sampleFunc 58 } 59 } 60 61 type tracerOptions struct { 62 tags map[string]string 63 name string 64 logger log.Logger 65 propagate bool 66 requestSampler func(r *http.Request) bool 67 } 68