server

import (
    "fmt"
    "net/http"
)

Serving

Have a struct that has a func, ServeHTTP will be called to service requests

type Hello struct {}

func (h Hello) ServeHTTP(w http.ResponseWriter, r *http.Request) { 
    fmt.Fprint(w, "<h1> Hello from Go </h1>")//print to writer object
}

Usage

func main() {
    var h Hello
    err := http.ListenAndServe("localhost:4000", h)
    checkError(err)
}