ctr: move tasks, run to commands package

Signed-off-by: Jess Valarezo <valarezo.jessica@gmail.com>

cmd/ctr/commands/tasks/tasks_unix.go

@@ -0,0 +1,64 @@
+// +build !windows
+
+package tasks
+
+import (
+	gocontext "context"
+	"os"
+	"os/signal"
+
+	"github.com/containerd/console"
+	"github.com/containerd/containerd"
+	"github.com/containerd/containerd/log"
+	"github.com/pkg/errors"
+	"golang.org/x/sys/unix"
+)
+
+// HandleConsoleResize resizes the console
+func HandleConsoleResize(ctx gocontext.Context, task resizer, con console.Console) error {
+	// do an initial resize of the console
+	size, err := con.Size()
+	if err != nil {
+		return err
+	}
+	if err := task.Resize(ctx, uint32(size.Width), uint32(size.Height)); err != nil {
+		log.G(ctx).WithError(err).Error("resize pty")
+	}
+	s := make(chan os.Signal, 16)
+	signal.Notify(s, unix.SIGWINCH)
+	go func() {
+		for range s {
+			size, err := con.Size()
+			if err != nil {
+				log.G(ctx).WithError(err).Error("get pty size")
+				continue
+			}
+			if err := task.Resize(ctx, uint32(size.Width), uint32(size.Height)); err != nil {
+				log.G(ctx).WithError(err).Error("resize pty")
+			}
+		}
+	}()
+	return nil
+}
+
+// NewTask creates a new task
+func NewTask(ctx gocontext.Context, client *containerd.Client, container containerd.Container, checkpoint string, tty, nullIO bool) (containerd.Task, error) {
+	if checkpoint == "" {
+		io := containerd.Stdio
+		if tty {
+			io = containerd.StdioTerminal
+		}
+		if nullIO {
+			if tty {
+				return nil, errors.New("tty and null-io cannot be used together")
+			}
+			io = containerd.NullIO
+		}
+		return container.NewTask(ctx, io)
+	}
+	im, err := client.GetImage(ctx, checkpoint)
+	if err != nil {
+		return nil, err
+	}
+	return container.NewTask(ctx, containerd.Stdio, containerd.WithTaskCheckpoint(im))
+}