Function parseLinuxDevice

cli/command/container/opts.go:1009–1040

parseLinuxDevice parses a device mapping string to a container.DeviceMapping struct knowing that the target is a Linux daemon

(device string)

// parseLinuxDevice parses a device mapping string to a container.DeviceMapping struct
// knowing that the target is a Linux daemon
func parseLinuxDevice(device string) (container.DeviceMapping, error) {
	var src, dst string
	permissions := "rwm"
	// We expect 3 parts at maximum; limit to 4 parts to detect invalid options.
	arr := strings.SplitN(device, ":", 4)
	switch len(arr) {
	case 3:
		permissions = arr[2]
		fallthrough
	case 2:
		if validDeviceMode(arr[1]) {
			permissions = arr[1]
		} else {
			dst = arr[1]
		}
		fallthrough
	case 1:
		src = arr[0]
	default:
		return container.DeviceMapping{}, fmt.Errorf("invalid device specification: %s", device)
	}

	if dst == "" {
		dst = src
	}

	return container.DeviceMapping{
		PathOnHost:        src,
		PathInContainer:   dst,
		CgroupPermissions: permissions,
	}, nil
}

// validateDeviceCgroupRule validates a device cgroup rule string format
// It will make sure 'val' is in the form: