Serving expvar when using gorilla/mux.

expvar_mux.go

package main

import (
    "expvar"
    "log"
    "net/http"

    "github.com/gorilla/mux"
)

var counter *expvar.Int

func init() {
    counter = expvar.NewInt("counter")
}

func rootHandler(w http.ResponseWriter, r *http.Request) {
    w.Write([]byte("Hello world!\n"))
    counter.Add(1)
}

func main() {
    r := mux.NewRouter()
    r.HandleFunc("/", rootHandler)
    r.Handle("/debug/vars", http.DefaultServeMux)
    log.Fatal(http.ListenAndServe(":8000", r))
}

If you use Mux.Handle("/debug/{*}", http.DefaultServeMux) then as well as the /debug/vars routes the traces

• /debug/requests
• /debug/events

Routes are also served.