Test for executing commands while using a context to terminate them within a certain time

main.go

package main

import (
	"log"
	"os/exec"
	"strconv"
	"time"

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

func main() {
	basectx := context.Background()

	ctx1, cancel1 := context.WithTimeout(basectx, 10*time.Second)
	defer cancel1()
	log.Printf("Context: 10s, Sleep:  5s, Expected: <nil>, Actual: %v", ex(ctx1, 5))

	ctx2, cancel2 := context.WithTimeout(basectx, 10*time.Second)
	defer cancel2()
	log.Printf("Context: 10s, Sleep: 60s, Expected: error, Actual: %s", ex(ctx2, 60))

}

func ex(ctx context.Context, sleeptime int) error {
	cmd := exec.Command("/bin/bash", "-c", "sleep "+strconv.Itoa(sleeptime))
	cmd.Start()

	cmdDone := make(chan error)
	go func(cmdDone chan error, cmd *exec.Cmd) { cmdDone <- cmd.Wait() }(cmdDone, cmd)

	for {
		select {
		case err := <-cmdDone:
			return err
		case <-ctx.Done():
			cmd.Process.Kill()
		}
	}
}

// Output:
//     # go run main.go
//     2016/07/22 11:08:07 Context: 10s, Sleep:  5s, Expected: <nil>, Actual: <nil>
//     2016/07/22 11:08:17 Context: 10s, Sleep: 60s, Expected: error, Actual: signal: killed