package main

...

func (app *application) logRequest(next http.Handler) http.Handler {
    return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
        var (
            ip     = r.RemoteAddr
            proto  = r.Proto
            method = r.Method
            uri    = r.URL.RequestURI()
        )

        app.logger.Info("received request", "ip", ip, "proto", proto, "method", method, "uri", uri)

        next.ServeHTTP(w, r)
    })
}

package main

import "net/http"

func (app *application) routes() http.Handler {
    mux := http.NewServeMux()

    fileServer := http.FileServer(http.Dir("./ui/static/"))
    mux.Handle("GET /static/", http.StripPrefix("/static", fileServer))

    mux.HandleFunc("GET /{$}", app.home)
    mux.HandleFunc("GET /snippet/view/{id}", app.snippetView)
    mux.HandleFunc("GET /snippet/create", app.snippetCreate)
    mux.HandleFunc("POST /snippet/create", app.snippetCreatePost)

    // Wrap the existing chain with the logRequest middleware.
    return app.logRequest(commonHeaders(mux))
}