crowdsecurity/crowdsec · error

empty host

Error message

empty host

What it means

When a VictoriaLogs datasource is configured via DSN string (victorialogs://...), ConfigureByDSN parses it as a URL and requires a host portion identifying the VictoriaLogs server. A DSN like 'victorialogs://' with no host returns 'empty host'.

Source

Thrown at pkg/acquisition/modules/victorialogs/config.go:134

func (s *Source) ConfigureByDSN(_ context.Context, dsn string, labels map[string]string, logger *log.Entry, uuid string) error {
	s.logger = logger
	s.Config = Configuration{}
	s.Config.Mode = configuration.CAT_MODE
	s.Config.Labels = labels
	s.Config.UniqueId = uuid

	u, err := url.Parse(dsn)
	if err != nil {
		return fmt.Errorf("while parsing dsn '%s': %w", dsn, err)
	}

	if u.Scheme != "victorialogs" {
		return fmt.Errorf("invalid DSN %s for VictoriaLogs source, must start with victorialogs://", dsn)
	}

	if u.Host == "" {
		return errors.New("empty host")
	}

	scheme := "http"

	params := u.Query()

	if q := params.Get("ssl"); q != "" {
		scheme = "https"
	}

	if q := params.Get("query"); q != "" {
		s.Config.Query = q
	}

	if w := params.Get("wait_for_ready"); w != "" {
		s.Config.WaitForReady, err = time.ParseDuration(w)
		if err != nil {
			return err

View on GitHub (pinned to 909b515798)

Solutions

1. Add the host to the DSN: victorialogs://victorialogs:9428
2. Include the full address with port if non-default
3. If config is generated, check the template renders the host variable

Example fix

// before
source: victorialogs://
// after
source: victorialogs://victorialogs:9428

// validate DSN shape before use
u, err := url.Parse(dsn)
if err != nil || u.Scheme != "victorialogs" || u.Host == "" { return errors.New("DSN must be victorialogs://host[:port]") }

When it happens

Trigger: DSN of the form 'victorialogs://' or 'victorialogs:///path' with no authority component in the acquisition config's 'source:' field.

Common situations: Incomplete DSN left in acquis.d/config after copying docs; host removed when templating; missing scheme+host because the user pasted only the path.

Understand the failure class

Background: "Invalid URL" / "URL cannot be empty": fix the malformed or missing URL behind request-construction failures — this error's family across 50 libraries.

Related errors

• VictoriaLogs url is mandatory
• VictoriaLogs query is mandatory
• invalid DSN %s for journalctl source, must start with journa
• unsupported key %s in journalctl DSN
• unknown parameter %s

AI-assisted analysis of crowdsecurity/crowdsec@909b515798 (2026-09-06). Data as JSON: /api/errors/72f364a95f071c96. Report an issue: GitHub.