/usr/share/gocode/src/github.com/opentracing-contrib/go-stdlib/nethttp/server.go is in golang-github-opentracing-contrib-go-stdlib-dev 0.0~git20170528.48e4d76-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 | // +build go1.7
package nethttp
import (
"net/http"
opentracing "github.com/opentracing/opentracing-go"
"github.com/opentracing/opentracing-go/ext"
)
type statusCodeTracker struct {
http.ResponseWriter
status int
}
func (w *statusCodeTracker) WriteHeader(status int) {
w.status = status
w.ResponseWriter.WriteHeader(status)
}
type mwOptions struct {
opNameFunc func(r *http.Request) string
componentName string
}
// MWOption controls the behavior of the Middleware.
type MWOption func(*mwOptions)
// OperationNameFunc returns a MWOption that uses given function f
// to generate operation name for each server-side span.
func OperationNameFunc(f func(r *http.Request) string) MWOption {
return func(options *mwOptions) {
options.opNameFunc = f
}
}
// MWComponentName returns a MWOption that sets the component name
// name for the server-side span.
func MWComponentName(componentName string) MWOption {
return func(options *mwOptions) {
options.componentName = componentName
}
}
// Middleware wraps an http.Handler and traces incoming requests.
// Additionally, it adds the span to the request's context.
//
// By default, the operation name of the spans is set to "HTTP {method}".
// This can be overriden with options.
//
// Example:
// http.ListenAndServe("localhost:80", nethttp.Middleware(tracer, http.DefaultServeMux))
//
// The options allow fine tuning the behavior of the middleware.
//
// Example:
// mw := nethttp.Middleware(
// tracer,
// http.DefaultServeMux,
// nethttp.OperationName(func(r *http.Request) string {
// return "HTTP " + r.Method + ":/api/customers"
// }),
// )
func Middleware(tr opentracing.Tracer, h http.Handler, options ...MWOption) http.Handler {
opts := mwOptions{
opNameFunc: func(r *http.Request) string {
return "HTTP " + r.Method
},
}
for _, opt := range options {
opt(&opts)
}
fn := func(w http.ResponseWriter, r *http.Request) {
ctx, _ := tr.Extract(opentracing.HTTPHeaders, opentracing.HTTPHeadersCarrier(r.Header))
sp := tr.StartSpan(opts.opNameFunc(r), ext.RPCServerOption(ctx))
ext.HTTPMethod.Set(sp, r.Method)
ext.HTTPUrl.Set(sp, r.URL.String())
// set component name, use "net/http" if caller does not specify
componentName := opts.componentName
if componentName == "" {
componentName = defaultComponentName
}
ext.Component.Set(sp, componentName)
w = &statusCodeTracker{w, 200}
r = r.WithContext(opentracing.ContextWithSpan(r.Context(), sp))
h.ServeHTTP(w, r)
ext.HTTPStatusCode.Set(sp, uint16(w.(*statusCodeTracker).status))
sp.Finish()
}
return http.HandlerFunc(fn)
}
|