golang-http-header/main.go

package main

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

func handler(w http.ResponseWriter, r *http.Request) {
	// Get the hostname of the server
	hostname, err := os.Hostname()
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	// Set the hostname in the response header
	w.Header().Set("Server-Hostname", hostname)

	// Send a response
	fmt.Fprintf(w, "This is server: %s\n", hostname)
}

func main() {
	// Define the handler function for incoming requests
	http.HandleFunc("/", handler)

	// Start the HTTP server on port 8000
	fmt.Println("Server listening on :8000...")
	err := http.ListenAndServe(":8000", nil)
	if err != nil {
		fmt.Println("Error:", err)
	}
}