package opencensus
import (
"go.opencensus.io/plugin/ochttp/propagation/b3"
"go.opencensus.io/trace"
"go.opencensus.io/trace/propagation"
)
// defaultHTTPPropagate holds OpenCensus' default HTTP propagation format which
// currently is Zipkin's B3.
var defaultHTTPPropagate propagation.HTTPFormat = &b3.HTTPFormat{}
// TracerOption allows for functional options to our OpenCensus tracing
// middleware.
type TracerOption func(o *TracerOptions)
// WithTracerConfig sets all configuration options at once.
func WithTracerConfig(options TracerOptions) TracerOption {
return func(o *TracerOptions) {
*o = options
}
}
// WithSampler sets the sampler to use by our OpenCensus Tracer.
func WithSampler(sampler trace.Sampler) TracerOption {
return func(o *TracerOptions) {
o.Sampler = sampler
}
}
// WithName sets the name for an instrumented transport endpoint. If name is omitted
// at tracing middleware creation, the method of the transport or transport rpc
// name is used.
func WithName(name string) TracerOption {
return func(o *TracerOptions) {
o.Name = name
}
}
// IsPublic should be set to true for publicly accessible servers and for
// clients that should not propagate their current trace metadata.
// On the server side a new trace will always be started regardless of any
// trace metadata being found in the incoming request. If any trace metadata
// is found, it will be added as a linked trace instead.
func IsPublic(isPublic bool) TracerOption {
return func(o *TracerOptions) {
o.Public = isPublic
}
}
// WithHTTPPropagation sets the propagation handlers for the HTTP transport
// middlewares. If used on a non HTTP transport this is a noop.
func WithHTTPPropagation(p propagation.HTTPFormat) TracerOption {
return func(o *TracerOptions) {
if p == nil {
// reset to default OC HTTP format
o.HTTPPropagate = defaultHTTPPropagate
return
}
o.HTTPPropagate = p
}
}
// TracerOptions holds configuration for our tracing middlewares
type TracerOptions struct {
Sampler trace.Sampler
Name string
Public bool
HTTPPropagate propagation.HTTPFormat
}