stress.go

package main

import (
        "flag"
        "fmt"
        "os"
        "os/exec"
        "os/signal"
        "sync"
)

var cliCount = flag.Int("n", 1, "number of concurrent CLIs")
var echoOutput = flag.Bool("e", false, "echo output from CLIs")
var appName = flag.String("a", "", "app name to tail logs for")

func main() {
        flag.Parse()

        killChan := make(chan os.Signal)
        signal.Notify(killChan, os.Kill, os.Interrupt)

        stopCommandsChan := make(chan struct{})

        go func() {
                <-killChan
                close(stopCommandsChan)
        }()

        procs := sync.WaitGroup{}
        counter := *cliCount
        for i := 0; i < *cliCount; i++ {
                fmt.Printf("Starting cli #%d\n", i)
                cmd := exec.Command("cf", "logs", *appName)

                if *echoOutput {
                        cmd.Stdout = os.Stdout
                        cmd.Stderr = os.Stderr
                }

                cmd.Start()
                go func() {
                        cmd.Wait()
                        counter--
                        println("###########################################################")
                        fmt.Printf("Lost one connection. Connections left: %d\n", counter)
                }()
                go func() {
                        <-stopCommandsChan
                        cmd.Process.Kill()
                        procs.Done()
                }()

                procs.Add(1)
        }

        procs.Wait()
}