Function applyServiceExtends

loader/extends.go:50–134

(ctx context.Context, name string, services map[string]any, opts *Options, tracker *cycleTracker, post PostProcessor)

}

func applyServiceExtends(ctx context.Context, name string, services map[string]any, opts *Options, tracker *cycleTracker, post PostProcessor) (any, error) {
	s := services[name]
	if s == nil {
		return nil, nil
	}
	service, ok := s.(map[string]any)
	if !ok {
		return nil, fmt.Errorf("services.%s must be a mapping", name)
	}
	extends, ok := service["extends"]
	if !ok {
		return s, nil
	}
	filename := ctx.Value(consts.ComposeFileKey{}).(string)
	var (
		err  error
		ref  string
		file any
	)
	switch v := extends.(type) {
	case map[string]any:
		ref, ok = v["service"].(string)
		if !ok {
			return nil, fmt.Errorf("extends.%s.service is required", name)
		}
		file = v["file"]
		opts.ProcessEvent("extends", v)
	case string:
		ref = v
		opts.ProcessEvent("extends", map[string]any{"service": ref})
	}

	var (
		base      any
		processor = post
	)

	if file != nil {
		refFilename := file.(string)
		services, processor, err = getExtendsBaseFromFile(ctx, name, ref, filename, refFilename, opts, tracker)
		if err != nil {
			return nil, err
		}
		filename = refFilename
	} else {
		_, ok := services[ref]
		if !ok {
			return nil, fmt.Errorf("cannot extend service %q in %s: service %q not found", name, filename, ref)
		}
	}

	tracker, err = tracker.Add(filename, name)
	if err != nil {
		return nil, err
	}

	// recursively apply `extends`
	base, err = applyServiceExtends(ctx, ref, services, opts, tracker, processor)