func checkSandbox(t *testing.T, info libnetwork.EndpointInfo) {
	origns, err := netns.Get()
	if err != nil {
		t.Fatalf("Could not get the current netns: %v", err)
	}
	defer origns.Close()

	key := info.Sandbox().Key()
	f, err := os.OpenFile(key, os.O_RDONLY, 0)
	if err != nil {
		t.Fatalf("Failed to open network namespace path %q: %v", key, err)
	}
	defer f.Close()

	runtime.LockOSThread()
	defer runtime.UnlockOSThread()

	nsFD := f.Fd()
	if err = netns.Set(netns.NsHandle(nsFD)); err != nil {
		t.Fatalf("Setting to the namespace pointed to by the sandbox %s failed: %v", key, err)
	}
	defer netns.Set(origns)

	_, err = netlink.LinkByName("eth0")
	if err != nil {
		t.Fatalf("Could not find the interface eth0 inside the sandbox: %v", err)
	}

	_, err = netlink.LinkByName("eth1")
	if err != nil {
		t.Fatalf("Could not find the interface eth1 inside the sandbox: %v", err)
	}
}
func checkSandbox(t *testing.T, info libnetwork.EndpointInfo) {
	key := info.Sandbox().Key()
	sbNs, err := netns.GetFromPath(key)
	if err != nil {
		t.Fatalf("Failed to get network namespace path %q: %v", key, err)
	}
	defer sbNs.Close()

	nh, err := netlink.NewHandleAt(sbNs)
	if err != nil {
		t.Fatal(err)
	}

	_, err = nh.LinkByName("eth0")
	if err != nil {
		t.Fatalf("Could not find the interface eth0 inside the sandbox: %v", err)
	}

	_, err = nh.LinkByName("eth1")
	if err != nil {
		t.Fatalf("Could not find the interface eth1 inside the sandbox: %v", err)
	}
}