Function validateUserConfig

pkg/alertmanager/api.go:204–290

Partially copied from: https://github.com/prometheus/alertmanager/blob/8e861c646bf67599a1704fc843c6a94d519ce312/cli/check_config.go#L65-L96

(logger log.Logger, cfg alertspb.AlertConfigDesc, limits Limits, user string)

// Partially copied from: https://github.com/prometheus/alertmanager/blob/8e861c646bf67599a1704fc843c6a94d519ce312/cli/check_config.go#L65-L96
func validateUserConfig(logger log.Logger, cfg alertspb.AlertConfigDesc, limits Limits, user string) error {
	// We don't have a valid use case for empty configurations. If a tenant does not have a
	// configuration set and issue a request to the Alertmanager, we'll a) upload an empty
	// config and b) immediately start an Alertmanager instance for them if a fallback
	// configuration is provisioned.
	if cfg.RawConfig == "" {
		return fmt.Errorf("configuration provided is empty, if you'd like to remove your configuration please use the delete configuration endpoint")
	}

	amCfg, err := config.Load(cfg.RawConfig)
	if err != nil {
		return err
	}

	// Validate the config recursively scanning it.
	if err := validateAlertmanagerConfig(amCfg); err != nil {
		return err
	}

	// Validate templates referenced in the alertmanager config.
	for _, name := range amCfg.Templates {
		if err := validateTemplateFilename(name); err != nil {
			return err
		}
	}

	// Check template limits.
	if l := limits.AlertmanagerMaxTemplatesCount(user); l > 0 && len(cfg.Templates) > l {
		return fmt.Errorf(errTooManyTemplates, len(cfg.Templates), l)
	}

	if maxSize := limits.AlertmanagerMaxTemplateSize(user); maxSize > 0 {
		for _, tmpl := range cfg.Templates {
			if size := len(tmpl.GetBody()); size > maxSize {
				return fmt.Errorf(errTemplateTooBig, tmpl.GetFilename(), size, maxSize)
			}
		}
	}

	// Validate template files.
	for _, tmpl := range cfg.Templates {
		if err := validateTemplateFilename(tmpl.Filename); err != nil {
			return err
		}
	}

	// Create templates on disk in a temporary directory.
	// Note: This means the validation will succeed if we can write to tmp but
	// not to configured data dir, and on the flipside, it'll fail if we can't write
	// to tmpDir. Ignoring both cases for now as they're ultra rare but will revisit if
	// we see this in the wild.
	userTempDir, err := os.MkdirTemp("", "validate-config-"+cfg.User)
	if err != nil {
		return err
	}
	defer os.RemoveAll(userTempDir)

	for _, tmpl := range cfg.Templates {