docker/cli · error

invalid field in config request

Error message

invalid field in config request: %s

What it means

Thrown by ConfigOpt.Set (config.go:67) when a config field key is not one of the recognized names: source/src, target, uid, gid, mode. Any other key (including typos or unsupported options) falls into the default switch case and is rejected with the offending key name.

Solutions

1. Use only the supported keys: source (or src), target, uid, gid, mode.
2. Check the Docker CLI/engine version — field sets differ across releases.
3. Spell the key exactly; although case-insensitive, the name must match the allowed set.
4. Consult `docker service create --help` for the current config syntax.

Example fix

// before
--config name=myconf,target=/etc/c
// after
--config source=myconf,target=/etc/c

// Allowlist the recognized --config field keys before submission.
var configKeys = map[string]bool{"source": true, "src": true, "target": true, "uid": true, "gid": true, "mode": true}
for _, f := range strings.Split(cfgVal, ",") {
    k, _, _ := strings.Cut(strings.ToLower(strings.TrimSpace(f)), "=")
    if !configKeys[k] { return fmt.Errorf("unknown config key %q", k) }
}

When it happens

Trigger: Passing `--config name=myconf` (should be `source=`), `--config path=/x`, `--config owner=root`, or any unrecognized key. The switch at line 50 lowercases the key, so case mismatches are tolerated but unknown keys hit default at line 66.

Common situations: Using the generic 'name' instead of 'source', inventing fields like 'path'/'owner'/'perms', or version skew where an older engine doesn't yet support a field you assumed existed.

Related errors

• invalid field ' ' must be a key=value pair
• invalid mode specified
• invalid field ' ' must be a key=value pair
• invalid field
• invalid protocol value

AI-assisted analysis of docker/cli@4f84911bfe (2026-08-07). Data as JSON: /api/errors/4024d48f8f272eaa. Report an issue: GitHub.

Appendix: source

Thrown at opts/swarmopts/config.go:67

		// TODO(thaJeztah): these options should not be case-insensitive.
		switch strings.ToLower(key) {
		case "source", "src":
			options.ConfigName = val
		case "target":
			options.File.Name = val
		case "uid":
			options.File.UID = val
		case "gid":
			options.File.GID = val
		case "mode":
			m, err := strconv.ParseUint(val, 0, 32)
			if err != nil {
				return fmt.Errorf("invalid mode specified: %v", err)
			}

			options.File.Mode = os.FileMode(m)
		default:
			return fmt.Errorf("invalid field in config request: %s", key)
		}
	}

	if options.ConfigName == "" {
		return errors.New("source is required")
	}
	if options.File.Name == "" {
		options.File.Name = options.ConfigName
	}

	o.values = append(o.values, options)
	return nil
}

// Type returns the type of this option
func (*ConfigOpt) Type() string {
	return "config"
}

View on GitHub (pinned to 4f84911bfe)