owasp-amass/amass · error

missing hostname in database URI

Error message

missing hostname in database URI

What it means

loadEngineURI parsed the engine API URI but u.Hostname() is empty — the URI has a scheme yet no host (e.g. "grpc:///path" or a malformed authority section). Without a hostname the API endpoint cannot be reached, so the guard rejects it. Also exercised by TestLoadEngineEnvSettings_MissingEnvSettings when AMASS_ENGINE_HOST is unset.

Solutions

1. Include the host in the engine URI, e.g. "grpc://127.0.0.1:2301"
2. Set AMASS_ENGINE_HOST (and port) when configuring via environment variables
3. Check for empty url.URL.Hostname() before accepting user- or env-provided URIs

When it happens

Trigger: Thrown at config/engineapi.go:123 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of owasp-amass/amass@79299dce87 (2026-09-06). Data as JSON: /api/errors/9c35dd86ae8709ec. Report an issue: GitHub.

Appendix: source

Thrown at config/engineapi.go:123

	return nil
}

// loadEngineURI takes the Engine API's URI as a string, parses it, and populates the EngAPI structure with the URI's components.
// It performs validations to ensure the URI contains a valid scheme and hostname. If parsing fails or any validation check doesn't pass,
// an error is returned. It also handles extracting authentication information and any additional options provided in the URI query.
func (c *Config) loadEngineURI(apiURI string) error {
	// Parse the raw URI string to a url.URL object. If the URI is malformed, an error is returned.
	u, err := url.Parse(apiURI)
	if err != nil {
		return err
	}
	// Check for valid scheme
	if u.Scheme == "" {
		return fmt.Errorf("missing scheme in database URI")
	}
	// Check for reachable hostname
	if u.Hostname() == "" {
		return fmt.Errorf("missing hostname in database URI")
	}
	// If the path is present in the URI and is more than just a "/", it's trimmed and used.
	// If the path is empty or just a "/", it defaults to an empty string.
	apiURIPath := ""
	// Only get the api file path name if it's not empty or a single slash
	if u.Path != "" && u.Path != "/" {
		apiURIPath = strings.TrimPrefix(u.Path, "/")
	}
	// Initialize a new EngAPI object with data from the parsed URI.
	api := &EngAPI{
		URL:      apiURI,
		Scheme:   u.Scheme,
		Username: u.User.Username(),
		Path:     apiURIPath,
		Host:     u.Hostname(), // Hostname without port
		Port:     u.Port(),     // Get port
	}
	// If a password is set in the URI, it's extracted and stored in the EngAPI object.

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