package main import ( "sync" "github.com/pkg/errors" "github.com/projectatomic/libpod/libpod" "github.com/sirupsen/logrus" "github.com/urfave/cli" ) var ( attachFlags = []cli.Flag{ cli.StringFlag{ Name: "detach-keys", Usage: "Override the key sequence for detaching a container. Format is a single character [a-Z] or ctrl- where is one of: a-z, @, ^, [, , or _.", }, cli.BoolFlag{ Name: "no-stdin", Usage: "Do not attach STDIN. The default is false.", }, } attachDescription = "The kpod attach command allows you to attach to a running container using the container's ID or name, either to view its ongoing output or to control it interactively." attachCommand = cli.Command{ Name: "attach", Usage: "Attach to a running container", Description: attachDescription, Flags: attachFlags, Action: attachCmd, ArgsUsage: "", } ) func attachCmd(c *cli.Context) error { args := c.Args() if err := validateFlags(c, attachFlags); err != nil { return err } if len(c.Args()) < 1 || len(c.Args()) > 1 { return errors.Errorf("attach requires the name or id of one running container") } runtime, err := getRuntime(c) if err != nil { return errors.Wrapf(err, "error creating libpod runtime") } defer runtime.Shutdown(false) ctr, err := runtime.LookupContainer(args[0]) if err != nil { return errors.Wrapf(err, "unable to exec into %s", args[0]) } conState, err := ctr.State() if err != nil { return errors.Wrapf(err, "unable to determine state of %s", args[0]) } if conState != libpod.ContainerStateRunning { return errors.Errorf("you can only attach to running containers") } // Create a bool channel to track that the console socket attach // is successful. attached := make(chan bool) // Create a waitgroup so we can sync and wait for all goroutines // to finish before exiting main var wg sync.WaitGroup // We increment the wg counter because we need to do the attach wg.Add(1) // Attach to the running container go func() { logrus.Debug("trying to attach to the container %s", ctr.ID()) defer wg.Done() if err := ctr.Attach(c.Bool("no-stdin"), c.String("detach-keys"), attached); err != nil { logrus.Errorf("unable to attach to container %s: %q", ctr.ID(), err) } }() if !<-attached { return errors.Errorf("unable to attach to container %s", ctr.ID()) } wg.Wait() return nil }