cannot supply extra formatting options to the pretty…

Error message

cannot supply extra formatting options to the pretty template

What it means

Identical logic to error 100 but for `docker service inspect`. After resolving the effective format string `f` (from `--format`, or from the Docker config file's `ServiceInspectFormat`, or defaulting to "raw"), this error fires at service/inspect.go:87-88 if `f` starts with "pretty" but is not exactly "pretty". Unlike the secret command, the format can also originate from the config file (`dockerCLI.ConfigFile().ServiceInspectFormat`), so a corrupted config value can trigger this without any `--format` flag on the command line.

Solutions

Use exactly `--format pretty` or a full Go template (no "pretty" prefix)
Check and fix the Docker config file (`~/.docker/config.json`) — look for a malformed `serviceInspectFormat` key and remove or correct it
Use `--pretty` instead of `--format pretty` to bypass the format-string logic entirely

Example fix

# before (command-line)
docker service inspect --format "pretty {{.ID}}" myservice

# after
docker service inspect --pretty myservice

# --- config file fix ---
# before (~/.docker/config.json):
# { "serviceInspectFormat": "pretty extra" }
# after:
# { "serviceInspectFormat": "" }

Defensive patterns

Strategy: validation

Validate before calling

// Validate effective format including config file fallback
func validateServiceFormat(format, configFormat string) error {
    f := format
    if len(f) == 0 {
        f = configFormat
    }
    if strings.HasPrefix(f, "pretty") && f != "pretty" {
        return fmt.Errorf("format %q is invalid: use 'pretty' exactly or a full Go template", f)
    }
    return nil
}

Prevention

Check ~/.docker/config.json for a malformed serviceInspectFormat value when debugging unexpected format errors
Use --pretty instead of --format pretty to avoid the format-string validation entirely
In automation, always pass --format explicitly (even if just 'json') to override any config file default

When it happens

Trigger: Passing `--format "pretty extra"` on the command line; or having `ServiceInspectFormat` set to a value like `"pretty foo"` in the Docker config file (`~/.docker/config.json`) while not passing `--format` on the CLI (lines 78-83 show the config file value is used as fallback).

Common situations: A Docker config file was manually edited or corrupted with a malformed `ServiceInspectFormat` value. Or a user tries to extend the pretty template with additional fields.

Related errors

AI-assisted analysis of docker/cli@4f84911bfe (2026-08-07). Data as JSON: /api/errors/f3035d87c04e6848. Report an issue: GitHub.

Appendix: source

Thrown at cli/command/service/inspect.go:88

		res, err := apiClient.NetworkInspect(ctx, ref, client.NetworkInspectOptions{Scope: "swarm"})
		if err == nil || !errdefs.IsNotFound(err) {
			return res.Network, res.Raw, err
		}
		return nil, nil, fmt.Errorf("no such network: %s", ref)
	}

	f := opts.format
	if len(f) == 0 {
		f = "raw"
		if len(dockerCLI.ConfigFile().ServiceInspectFormat) > 0 {
			f = dockerCLI.ConfigFile().ServiceInspectFormat
		}
	}

	// check if the user is trying to apply a template to the pretty format, which
	// is not supported
	if strings.HasPrefix(f, "pretty") && f != "pretty" {
		return errors.New("cannot supply extra formatting options to the pretty template")
	}

	serviceCtx := formatter.Context{
		Output: dockerCLI.Out(),
		Format: newFormat(f),
	}

	if err := inspectFormatWrite(serviceCtx, opts.refs, getRef, getNetwork); err != nil {
		return cli.StatusError{StatusCode: 1, Status: err.Error()}
	}
	return nil
}

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