Function runScale

cli/command/service/scale.go:57–93

(ctx context.Context, dockerCLI command.Cli, options *scaleOptions, args []string)

}

func runScale(ctx context.Context, dockerCLI command.Cli, options *scaleOptions, args []string) error {
	apiClient := dockerCLI.Client()
	var (
		errs       []error
		serviceIDs = make([]string, 0, len(args))
	)
	for _, arg := range args {
		serviceID, scaleStr, _ := strings.Cut(arg, "=")

		// validate input arg scale number
		scale, err := strconv.ParseUint(scaleStr, 10, 64)
		if err != nil {
			errs = append(errs, fmt.Errorf("%s: invalid replicas value %s: %v", serviceID, scaleStr, err))
			continue
		}

		warnings, err := runServiceScale(ctx, apiClient, serviceID, scale)
		if err != nil {
			errs = append(errs, fmt.Errorf("%s: %v", serviceID, err))
			continue
		}
		for _, warning := range warnings {
			_, _ = fmt.Fprintln(dockerCLI.Err(), warning)
		}
		_, _ = fmt.Fprintf(dockerCLI.Out(), "%s scaled to %d\n", serviceID, scale)
		serviceIDs = append(serviceIDs, serviceID)
	}

	if len(serviceIDs) > 0 && !options.detach {
		for _, serviceID := range serviceIDs {
			if err := WaitOnService(ctx, dockerCLI, serviceID, false); err != nil {
				errs = append(errs, fmt.Errorf("%s: %v", serviceID, err))
			}
		}
	}
	return errors.Join(errs...)
}

func runServiceScale(ctx context.Context, apiClient client.ServiceAPIClient, serviceID string, scale uint64) (warnings []string, _ error) {
	res, err := apiClient.ServiceInspect(ctx, serviceID, client.ServiceInspectOptions{})