func doCmd(instance *beam.Object, args []string) error {
if len(args) == 0 {
return fmt.Errorf("no command supplied")
}
if args[0] == "ps" {
if len(args) != 1 {
return fmt.Errorf("usage: ps")
}
names, err := instance.Ls()
if err != nil {
return err
}
fmt.Println(strings.Join(names, "\n"))
return nil
}
if args[0] == "run" {
if len(args) < 3 {
return fmt.Errorf("usage: run IMAGE COMMAND...")
}
containerJson, err := json.Marshal(&runconfig.Config{
Image: args[1],
Cmd: args[2:],
AttachStdin: false,
AttachStdout: true,
AttachStderr: true,
})
if err != nil {
return err
}
container, err := instance.Spawn(string(containerJson))
if err != nil {
return fmt.Errorf("spawn: %v", err)
}
logs, _, err := container.Attach("")
if err != nil {
return fmt.Errorf("attach: %v", err)
}
if err = container.Start(); err != nil {
return fmt.Errorf("start: %v", err)
}
for {
msg, err := logs.Receive(beam.Ret)
if err != nil {
if err.Error() == "EOF" {
break
}
return fmt.Errorf("error reading from container: %v", err)
}
if msg.Verb != beam.Log {
return fmt.Errorf("unexpected message reading from container: %v", msg)
}
if len(msg.Args) != 2 {
return fmt.Errorf("expected exactly 2 args to log message, got %d", len(msg.Args))
}
tag, chunk := msg.Args[0], msg.Args[1]
var stream io.Writer
if tag == "stdout" {
stream = os.Stdout
} else if tag == "stderr" {
stream = os.Stderr
} else {
return fmt.Errorf("unrecognised tag: %s", tag)
}
fmt.Fprint(stream, chunk)
}
return nil
}
if args[0] == "inspect" {
if len(args) != 2 {
return fmt.Errorf("usage: inspect CONTAINER")
}
_, container, err := instance.Attach(args[1])
if err != nil {
return fmt.Errorf("attach: %v", err)
}
json, err := container.Get()
if err != nil {
return fmt.Errorf("get: %v", err)
}
fmt.Println(json)
return nil
}
return fmt.Errorf("unrecognised command: %s", args[0])
}
