ExtractSampledTraceID works like ExtractTraceID but the returned bool is only true if the returned trace id is sampled.

ExtractTraceID extracts the trace id, if any from the context.

MakeLabelValue converts a Gorilla mux path to a string suitable for use in a Prometheus label value.

Merge produces a middleware that applies multiple middlewares in turn; ie Merge(f,g,h).Wrap(handler) == f.Wrap(g.Wrap(h.Wrap(handler))).

BodySizeBuckets defines buckets for request/response body sizes.

DefBuckets are histogram buckets for the response time (in seconds) of a network service, including one that is responding very slowly.

Instrument is a Middleware which records timings for every HTTP request.

Tracer is a middleware which traces incoming requests.

Interface is the shared contract for all middleware, and allows middlewares to wrap handlers.

RouteMatcher matches routes.

Func is to Interface as http.HandlerFunc is to http.Handler.