package tracing import ( "fmt" "net/http" "github.com/containous/traefik/log" "github.com/opentracing/opentracing-go/ext" "github.com/urfave/negroni" ) type forwarderMiddleware struct { frontend string backend string opName string *Tracing } // NewForwarderMiddleware creates a new forwarder middleware that traces the outgoing request func (t *Tracing) NewForwarderMiddleware(frontend, backend string) negroni.Handler { log.Debugf("Added outgoing tracing middleware %s", frontend) return &forwarderMiddleware{ Tracing: t, frontend: frontend, backend: backend, opName: fmt.Sprintf("forward %s/%s", frontend, backend), } } func (f *forwarderMiddleware) ServeHTTP(w http.ResponseWriter, r *http.Request, next http.HandlerFunc) { span, r, finish := StartSpan(r, f.opName, true) defer finish() span.SetTag("frontend.name", f.frontend) span.SetTag("backend.name", f.backend) ext.HTTPMethod.Set(span, r.Method) ext.HTTPUrl.Set(span, r.URL.String()) span.SetTag("http.host", r.Host) InjectRequestHeaders(r) w = &statusCodeTracker{w, 200} next(w, r) LogResponseCode(span, w.(*statusCodeTracker).status) }