What causes "invalid no_ready_check in dsn: %w" in crowdsecurity/crowdsec?

Use no_ready_check=true or no_ready_check=false in the DSN

invalid no_ready_check in dsn: %w

Error message

invalid no_ready_check in dsn: %w

What it means

ConfigureByDSN validates the optional 'no_ready_check' DSN boolean with strconv.ParseBool. Only 'true'/'false'/'1'/'0'/'t'/'f'/'T'/'F'/'TRUE'/'FALSE' style values are accepted; anything else triggers this error.

Source

Thrown at pkg/acquisition/modules/loki/config.go:211

		l.Config.Limit = limit
	} else {
		l.Config.Limit = 5000 // max limit allowed by loki
	}

	if logLevel := params.Get("log_level"); logLevel != "" {
		level, err := log.ParseLevel(logLevel)
		if err != nil {
			return fmt.Errorf("invalid log_level in dsn: %w", err)
		}

		l.Config.LogLevel = level
		l.logger.Logger.SetLevel(level)
	}

	if noReadyCheck := params.Get("no_ready_check"); noReadyCheck != "" {
		noReadyCheck, err := strconv.ParseBool(noReadyCheck)
		if err != nil {
			return fmt.Errorf("invalid no_ready_check in dsn: %w", err)
		}

		l.Config.NoReadyCheck = noReadyCheck
	}

	l.Config.URL = fmt.Sprintf("%s://%s", scheme, u.Host)
	if u.User != nil {
		l.Config.Auth.Username = u.User.Username()
		l.Config.Auth.Password, _ = u.User.Password()
	}

	clientConfig := lokiclient.Config{
		LokiURL:  l.Config.URL,
		Headers:  l.Config.Headers,
		Limit:    l.Config.Limit,
		Query:    l.Config.Query,
		Since:    l.Config.Since,
		Username: l.Config.Auth.Username,

View on GitHub (pinned to 909b515798)

Solutions

Use no_ready_check=true or no_ready_check=false in the DSN
Remove the parameter (the ready check runs by default)

Example fix

// before
loki://localhost:3100/?no_ready_check=yes
// after
loki://localhost:3100/?no_ready_check=true

Defensive patterns

Strategy: validation

Validate before calling

if v := params.Get("no_ready_check"); v != "" {
    if _, err := strconv.ParseBool(v); err != nil {
        return fmt.Errorf("no_ready_check must be a Go-parseable bool (true/false/1/0/t/f)")
    }
}

Prevention

Only use true/false in URL query booleans
Remember query strings are not YAML — 'yes'/'on' are invalid

When it happens

Trigger: A DSN like loki://host:3100/?no_ready_check=yes or no_ready_check=on is configured.

Common situations: Using YAML-style booleans ('yes'/'no') or 'enabled' in the URL query string.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

AI-assisted analysis of crowdsecurity/crowdsec@909b515798 (2026-09-06). Data as JSON: /api/errors/d20d9919afc2464d. Report an issue: GitHub.