docker/cli · error

invalid field: %s

Error message

invalid field: %s

What it means

Error "invalid field: %s" thrown in docker/cli.

Source

Thrown at opts/swarmopts/port.go:56

	if err != nil {
		return err
	}
	if longSyntax {
		csvReader := csv.NewReader(strings.NewReader(value))
		fields, err := csvReader.Read()
		if err != nil {
			return err
		}

		pConfig := swarm.PortConfig{
			Protocol:    network.TCP,
			PublishMode: swarm.PortConfigPublishModeIngress,
		}
		for _, field := range fields {
			// TODO(thaJeztah): these options should not be case-insensitive.
			key, val, ok := strings.Cut(strings.ToLower(field), "=")
			if !ok || key == "" {
				return fmt.Errorf("invalid field: %s", field)
			}
			switch key {
			case portOptProtocol:
				switch proto := network.IPProtocol(val); proto {
				case network.TCP, network.UDP, network.SCTP:
					pConfig.Protocol = proto
				default:
					return fmt.Errorf("invalid protocol value '%s'", val)
				}
			case portOptMode:
				switch swarm.PortConfigPublishMode(val) {
				case swarm.PortConfigPublishModeIngress, swarm.PortConfigPublishModeHost:
					pConfig.PublishMode = swarm.PortConfigPublishMode(val)
				default:
					return fmt.Errorf("invalid publish mode value (%s): must be either '%s' or '%s'", val, swarm.PortConfigPublishModeIngress, swarm.PortConfigPublishModeHost)
				}
			case portOptTargetPort:
				tPort, err := strconv.ParseUint(val, 10, 16)

View on GitHub (pinned to e9452d6e78)

When it happens

Trigger: Thrown at opts/swarmopts/port.go:56 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/87ef418f49b0de67.json. Report an issue: GitHub.