Built-in Go HTTP server

Go has a built-in HTTP server in net/http.

Here’s me playing around using it:

package main

import (
	"fmt"
	"net/http"
	"strings"
)

func hello(w http.ResponseWriter, req *http.Request) {

	fmt.Fprintf(w, "hello\n")
}

func details(w http.ResponseWriter, req *http.Request) {

	resp := []string{}

	resp = append(resp, "Request Details:")
	resp = append(resp, fmt.Sprintf("- Request proto: %s", req.Proto))

	resp = append(resp, fmt.Sprintf("- Headers:"))
	for name, val := range req.Header {
		resp = append(resp, fmt.Sprintf("\t- %s: %s", name, val))
	}

	resp = append(resp, "\n")
	fmt.Fprintf(w, strings.Join(resp, "\n"))
}

func main() {

	http.HandleFunc("/hello", hello)
	http.HandleFunc("/details", details)

	fmt.Println("Started.")
	http.ListenAndServe("127.0.0.1:9999", nil)
	fmt.Println("Exiting.")
}

The /details endpoint returns interesting stuff about the HTTP request, like its protocol and headers:

$ curl -s -H "X-Simas-Token: hunter2" localhost:9999/details
Request Details:
- Request proto: HTTP/1.1
- Headers:
	- User-Agent: [curl/7.79.1]
	- Accept: [*/*]
	- X-Simas-Token: [hunter2]

There’s some fantastic examples of what this is capable of in Eli Bendersky’s post Serving static files and web apps in Go.