How can I read a header from an http request in golang?

Question

If I receive a request of type http.Request, how can I read the value of a specific header? In this case I want to pull the value of a jwt token out of the request header.

Answer 1

You can use the r.Header.Get:

func yourHandler(w http.ResponseWriter, r *http.Request) {     ua := r.Header.Get("User-Agent")     ... } 

Answer 2

package main  import (     "fmt"     "log"     "net/http" )  func main() {     http.HandleFunc("/", handler)     log.Fatal(http.ListenAndServe("localhost:8000", nil)) }  func handler(w http.ResponseWriter, r *http.Request) {     fmt.Fprintf(w, "%s %s %s \n", r.Method, r.URL, r.Proto)     //Iterate over all header fields     for k, v := range r.Header {         fmt.Fprintf(w, "Header field %q, Value %q\n", k, v)     }      fmt.Fprintf(w, "Host = %q\n", r.Host)     fmt.Fprintf(w, "RemoteAddr= %q\n", r.RemoteAddr)     //Get value for a specified token     fmt.Fprintf(w, "\n\nFinding value of \"Accept\" %q", r.Header["Accept"]) } 

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Connecting to http://localhost:8000/ from a browser will print the output in the browser.