docker/cli · error

missing mandatory field '%s'

Error message

missing mandatory field '%s'

What it means

Error "missing mandatory field '%s'" thrown in docker/cli.

Source

Thrown at opts/swarmopts/port.go:101

				pConfig.TargetPort = uint32(tPort)
			case portOptPublishedPort:
				pPort, err := strconv.ParseUint(val, 10, 16)
				if err != nil {
					var numErr *strconv.NumError
					if errors.As(err, &numErr) {
						err = numErr.Err
					}
					return fmt.Errorf("invalid published port (%s): value must be an integer: %w", val, err)
				}

				pConfig.PublishedPort = uint32(pPort)
			default:
				return fmt.Errorf("invalid field key: %s", key)
			}
		}

		if pConfig.TargetPort == 0 {
			return fmt.Errorf("missing mandatory field '%s'", portOptTargetPort)
		}

		p.ports = append(p.ports, pConfig)
	} else {
		// short syntax ([ip:]public:private[/proto])
		//
		// TODO(thaJeztah): we need an equivalent that handles the "ip-address" part without depending on the nat package.
		ports, portBindingMap, err := nat.ParsePortSpecs([]string{value})
		if err != nil {
			return err
		}
		for _, portBindings := range portBindingMap {
			for _, portBinding := range portBindings {
				if portBinding.HostIP != "" {
					return errors.New("hostip is not supported")
				}
			}
		}

View on GitHub (pinned to e9452d6e78)

When it happens

Trigger: Thrown at opts/swarmopts/port.go:101 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of docker/cli@e9452d6e78 (2026-08-01). Data as JSON: /data/errors/1d51844427403302.json. Report an issue: GitHub.