Generating concurrent HTTP/HTTPS requests

conreq.go

package main

import (
	"flag"
	"fmt"
	"net/http"
	"strconv"
	"time"
)

func worker(id int, jobs <-chan string, results chan<- string) {
	for url := range jobs {
		fmt.Println("worker", id, "requesting to", url)
		resp, err := http.Get(url)
		if err != nil {
			fmt.Println(err)
			time.Sleep(time.Second)
			continue
		}
		resp.Body.Close()
		fmt.Println("worker", id, "got response for", url, "status:", resp.StatusCode)
		results <- resp.Status
	}
}

func main() {
	// The tool needs three parameters.
	// Number of workers (Default: 5)
	// Number of HTTP requests (Default: 1)
	// Target URL (Default: https://repro.global.ssl.fastly.net/"

	// For 20 workers to process 10000 requests toward the default target URL
	// go run conreq.go -w 20 -r 10000
	var requestCnt, workerCnt int
	var baseUrl string
	m := make(map[string]int)
	flag.IntVar(&workerCnt, "w", 5, "Number of workers")
	flag.IntVar(&requestCnt, "r", 1, "Number of HTTP requests")
	flag.StringVar(&baseUrl, "u", "https://repro.global.ssl.fastly.net/", "Target URL")
	flag.Parse()

	jobs := make(chan string, requestCnt)
	results := make(chan string, requestCnt)

	for w := 1; w <= workerCnt; w++ {
		go worker(w, jobs, results)
	}

	for j := 1; j <= requestCnt; j++ {
		url := baseUrl + strconv.Itoa(j)
		jobs <- url
	}
	close(jobs)

	for a := 1; a <= requestCnt; a++ {
		status := <-results
		m[status]++
	}

	fmt.Println("------------------------------")
	for status, count := range m {
		fmt.Printf("%v / %v\n", status, count)
	}
}