Gorilla mux custom middleware

softshipper picture softshipper · Oct 5, 2014 · Viewed 32.5k times · Source

I am using gorilla mux for manage routing. What I am missing is to integrate a middleware between every request.

For example

package main

import (
    "fmt"
    "github.com/gorilla/mux"
    "log"
    "net/http"
    "strconv"
)

func HomeHandler(response http.ResponseWriter, request *http.Request) {

    fmt.Fprintf(response, "Hello home")
}

func main() {

    port := 3000
    portstring := strconv.Itoa(port)

    r := mux.NewRouter()
    r.HandleFunc("/", HomeHandler)
    http.Handle("/", r)

    log.Print("Listening on port " + portstring + " ... ")
    err := http.ListenAndServe(":"+portstring, nil)
    if err != nil {
        log.Fatal("ListenAndServe error: ", err)
    }
}

Every incoming request should pass through the middleware. How can I integrate here a midleware?

Update

I will use it in combination with gorilla/sessions, and they say:

Important Note: If you aren't using gorilla/mux, you need to wrap your handlers with context.ClearHandler as or else you will leak memory! An easy way to do this is to wrap the top-level mux when calling http.ListenAndServe:

How can I prevent this scenario?

Answer

OneOfOne picture OneOfOne · Oct 5, 2014

Just create a wrapper, it's rather easy in Go:

func HomeHandler(response http.ResponseWriter, request *http.Request) {

    fmt.Fprintf(response, "Hello home")
}

func Middleware(h http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        log.Println("middleware", r.URL)
        h.ServeHTTP(w, r)
    })
}
func main() {
    r := mux.NewRouter()
    r.HandleFunc("/", HomeHandler)
    http.Handle("/", Middleware(r))
}