400-exit-code

400-exit-codes

Just like os/exec package, dexec also returns an ExitError type that you can collect valuable information such as:

• ExitCode int
• Stderr []byte if process was started using Output() method.

In this example, we start a program that is supposed to fail:

/bin/sh -c "exit 255;"

To run this example:

$ docker pull busybox
$ go run main.go
exit code=255

Migration from os/exec

> 	cl, _ := docker.NewClientFromEnv()
> 	d := dexec.Docker{cl}
> 
> 	m, _ := dexec.ByCreatingContainer(docker.CreateContainerOptions{
> 		Config: &docker.Config{Image: "busybox"}})
> 
< 	cmd := exec.Command("sh", "-c", "exit 255;")
> 	cmd := d.Command(m, "sh", "-c", "exit 255;")
< 	if ee, ok := err.(*exec.ExitError); ok {
< 		fmt.Printf("exit code=%d\n", ee.Sys().(syscall.WaitStatus).ExitStatus())
> 	if ee, ok := err.(*dexec.ExitError); ok {
> 		fmt.Printf("exit code=%d\n", ee.ExitCode)