Raw HTTP packet digest with Golang

raw-http.go

package main

import (
 "io/ioutil"
 "net/http"
 "strings"
 "fmt"
 "log"
)

func main() {
 // GET request
 http.HandleFunc("/", getHandler)
 // POST request
 http.HandleFunc("/data", postHandler)
 // Server
 http.ListenAndServe(":9000", nil)
}

func getHandler(w http.ResponseWriter, r *http.Request) {
 // HTTP Version
 proto := r.Proto
 fmt.Fprintln(w, "Proto: ", proto)
 // Method
 method := r.Method
 fmt.Fprintln(w, "Method: ", method)
 // Showing the URI
 requestURI := r.RequestURI
 fmt.Fprintln(w, "Request URI: ", requestURI)
 // The complete URL
 url := r.URL
 //URL Has parts
 fmt.Fprintln(w, "URL: ", url.String())
 fmt.Fprintln(w, "URL Scheme: ", url.Scheme)
 fmt.Fprintln(w, "URL Host: ", url.Host)
 fmt.Fprintln(w, "URL Path: ", url.Path)
 fmt.Fprintln(w, "URL RawQuery: ", url.RawQuery)
 fmt.Fprintln(w, "URL Fragment: ", url.Fragment)
 // Hostname and Port
 hostname := url.Hostname()
 port := url.Port()
 fmt.Fprintln(w, "Hostname: ", hostname, ", Port: ", port)
 // Handling query params (map)
 queryValues := url.Query()
 fmt.Fprintln(w, "Query Values: ")
 // Iterating
 for key, val := range queryValues {
  fmt.Fprintln(w, key+": "+strings.Join(val, ","))
 }
 // Headers
 headers := ""
 for k, v := range r.Header {
   headers += k + "=" + strings.Join(v, ",") + "\n"
 }
 // Printing headers
 fmt.Fprintln(w, "Headers: \n"+headers)
 // Custom-Header
 myHeader := r.Header.Get("Custom-Header")
 fmt.Fprintln(w, "Custom-Header: "+myHeader)
 // Another headers
 fmt.Fprintln(w, "Referer: "+r.Referer())     //Refering URL
 fmt.Fprintln(w, "UserAgent: "+r.UserAgent()) //Client
 // Remote address
 remoteAddress := r.RemoteAddr
 fmt.Fprintln(w, "Remote Address: "+remoteAddress)
 // Body
 body, err := ioutil.ReadAll(r.Body)
 if err != nil {
   log.Println("Error Reading Body")
 }
 // converting body in string
 fmt.Fprintln(w, "Body: ", string(body))
}

func postHandler(w http.ResponseWriter, r *http.Request) {
 //First we need to call ParseForm
 err := r.ParseForm()
 if err != nil {
  fmt.Fprintf(w, "Error with form")
 }
 // method
 method := r.Method
 fmt.Fprintln(w, "Method: ", method)
 // Request URI
 requestURI := r.RequestURI
 fmt.Fprintln(w, "Request URI: ", requestURI)
 //Post and Patch values And Also Querystring
 for key, val := range r.Form {
   fmt.Fprintln(w, key,  ": ", strings.Join(val, ","))
 }
 // Get an individual value from form
 custom := r.Form.Get("Custom-value")
 fmt.Fprintln(w, "Custom-value: "+ custom)
}