Golang http vomit comet

main.go

package main

import (
	"crypto/rand"
	"errors"
	"fmt"
	"io"
	"net/http"
	"strconv"
)

func writeRand(s int, writer io.Writer) error {
	b := make([]byte, s)
	_, err := rand.Read(b)
	if err != nil {
		return err
	}
	writer.Write(b)
	return nil
}

func getRoot(w http.ResponseWriter, r *http.Request) {
	hasSize := r.URL.Query().Has("size")
	size := r.URL.Query().Get("size")
	if hasSize {
		s, err := strconv.Atoi(size)
		if err != nil {
			http.Error(w, fmt.Sprintf("unable to convert size to integer: %v", err), http.StatusBadRequest)
		}
		err = writeRand(s, w)
		if err != nil {
			http.Error(w, fmt.Sprintf("unable to copy data to socket: %v", err), http.StatusBadRequest)
		}
		return
	}
	io.WriteString(w, "Hello world\n")
}

func main() {
	mux := http.NewServeMux()
	mux.HandleFunc("/", getRoot)

	server := &http.Server{
		Addr:    ":3333",
		Handler: mux,
	}

	err := server.ListenAndServe()
	if errors.Is(err, http.ErrServerClosed) {
		fmt.Printf("server closed\n")
	} else if err != nil {
		fmt.Printf("error listening for server: %s\n", err)
	}
}