gofr-dev/gofr · error

unsupported config file format: %s (supported: .json, .yaml,

Error message

unsupported config file format: %s (supported: .json, .yaml, .yml): %w

What it means

LoadPermissions only supports .json, .yaml, and .yml config files (extension-less files are treated as JSON). Any other extension — .toml, .conf, .txt, .xml — is rejected with errUnsupportedFormat and the RBAC config is not loaded.

Source

Thrown at pkg/gofr/rbac/config.go:154

	if err != nil {
		return nil, fmt.Errorf("failed to read RBAC config file %s: %w", path, err)
	}

	var config Config

	// Detect file format by extension
	ext := strings.ToLower(filepath.Ext(path))
	switch ext {
	case ".yaml", ".yml":
		if err := yaml.Unmarshal(data, &config); err != nil {
			return nil, fmt.Errorf("failed to parse YAML config file %s: %w", path, err)
		}
	case ".json", "":
		if err := json.Unmarshal(data, &config); err != nil {
			return nil, fmt.Errorf("failed to parse JSON config file %s: %w", path, err)
		}
	default:
		return nil, fmt.Errorf("unsupported config file format: %s (supported: .json, .yaml, .yml): %w", ext, errUnsupportedFormat)
	}

	// Set dependencies
	config.Logger = logger
	config.Metrics = metrics
	config.Tracer = tracer

	// Initialize mux router for pattern matching
	// Use StrictSlash(false) to match the application router's behavior
	config.muxRouter = mux.NewRouter().StrictSlash(false)

	// Validate config before processing
	if err := config.validate(); err != nil {
		return nil, fmt.Errorf("invalid RBAC config: %w", err)
	}

	// Process unified config to build internal maps
	if err := config.processUnifiedConfig(); err != nil {

View on GitHub (pinned to 187eb24962)

Solutions

1. Rename the config file to one of the supported extensions (.json, .yaml, .yml).
2. Convert unsupported formats (TOML/INI/XML) to JSON or YAML.
3. If the file is intentionally extension-less, ensure its content is valid JSON since "" falls into the JSON branch.

Example fix

// before
config, err := rbac.LoadPermissions("configs/rbac.toml", ...)
// after
config, err := rbac.LoadPermissions("configs/rbac.yaml", ...)

ext := strings.ToLower(filepath.Ext(path))
switch ext {
case ".json", "", ".yaml", ".yml":
    // ok
default:
    return fmt.Errorf("config %s has unsupported extension %q; use .json/.yaml/.yml", path, ext)
}

config, err := rbac.LoadPermissions(path, logger, metrics, tracer)
if err != nil && strings.Contains(err.Error(), "unsupported config file format") {
    logger.Fatalf("rename %s to .json/.yaml/.yml", path)
}

When it happens

Trigger: Passing EnableRBAC/LoadPermissions a path ending in an extension outside {.json, .yaml, .yml}, e.g. /etc/app/rbac.toml or rbac.config.

Common situations: Reusing an existing TOML/INI config; a deployment renamed the file to .bak or added a timestamp suffix; writing config as .yml.txt due to editor auto-extension.

Related errors

• failed to parse YAML config file %s: %w
• failed to parse JSON config file %s: %w
• invalid RBAC config: %w
• failed to process unified config: %w
• endpoint[%d]: %w: %s

AI-assisted analysis of gofr-dev/gofr@187eb24962 (2026-09-01). Data as JSON: /api/errors/82bfaa05f6d10d3a. Report an issue: GitHub.