client.go

package main

import (
	"context"
	"crypto/rand"
	"crypto/tls"
	"fmt"
	"io"
	"net"
	"net/http"
	"os"
	"strings"
	"time"

	"golang.org/x/net/http2"
)

func connectionUsingRandomClient(address string, numberOfBytes int, batchSize int, timeBetweenBatches int) error {
	fmt.Fprintf(os.Stdout, "%d bytes will be send to %s \n", numberOfBytes, address)

	transport := &http2.Transport{
		// So http2.Transport doesn't complain the URL scheme isn't 'https'
		AllowHTTP:       true,
		TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
	}

	if strings.HasPrefix(address, "http:") {
		transport.DialTLSContext = func(ctx context.Context, network, addr string, _ *tls.Config) (net.Conn, error) {
			var d net.Dialer
			return d.DialContext(ctx, network, addr)
		}
	}

	client := http.Client{
		Transport: transport,
	}

	r, w := io.Pipe()

	go func() {
		defer w.Close()
		for i := 0; i < numberOfBytes || numberOfBytes < 0; {
			size := batchSize
			if size+i > numberOfBytes && numberOfBytes > -1 {
				size = numberOfBytes - i
			}

			out := make([]byte, size)

			rand.Read(out)

			i += size

			fmt.Println("Sending data")
			_, _ = w.Write(out)

			time.Sleep(time.Duration(timeBetweenBatches) * time.Millisecond)
		}
	}()

	resp, err := client.Post(address, "", r)

	if err != nil {
		return err
	}

	bIn := make([]byte, 1024)

	received := 0
	n, err := resp.Body.Read(bIn)

	for ; err == nil; n, err = resp.Body.Read(bIn) {

		if n == 0 {
			continue
		}
		fmt.Println("Receiving data")
		received += n
	}

	fmt.Fprintf(os.Stdout, "%d bytes received from %s \n", received, address)

	if err != io.EOF {
		return err
	}

	return nil

}