func LoadConfig()

in plugins/internal/plugin/plugin_configuration.go [73:145]
45 lines of code
8 McCabe index (conditional complexity)

func LoadConfig(pluginName string, logger *zap.SugaredLogger) (*PluginConfig, error) {

	// Set our default configuration values
	v := viper.New()
	v.SetDefault("multitenancy", 0)
	v.SetDefault("includeIntegrated", false)
	v.SetDefault("includeDetachable", false)
	v.SetDefault("additionalMounts", make(map[string][]*discovery.RuntimeFile))
	v.SetDefault("additionalMountsWow64", make(map[string][]*discovery.RuntimeFile))

	// The names of our environment variables reflect the plugin name
	envPrefix := fmt.Sprint(strings.ToUpper(pluginName), "_DEVICE_PLUGIN_")
	v.BindEnv("multitenancy", fmt.Sprint(envPrefix, "MULTITENANCY"))
	v.BindEnv("includeIntegrated", fmt.Sprint(envPrefix, "INCLUDE_INTEGRATED"))
	v.BindEnv("includeDetachable", fmt.Sprint(envPrefix, "INCLUDE_DETACHABLE"))

	// Check if a config file path was explicitly specified through an environment variable
	configPath, configPathExists := os.LookupEnv(fmt.Sprint(envPrefix, "CONFIG_FILE"))
	if configPathExists {

		// Verify that the specified value is an absolute path
		if !filepath.IsAbs(configPath) {
			return nil, errors.New("configuration file path must be an absolute path")
		}

		// Verify that the specified file exists
		if _, err := os.Stat(configPath); errors.Is(err, fs.ErrNotExist) {
			return nil, fmt.Errorf("specified configuration file does not exist: %s", configPath)
		}

		// Use the specified path
		v.SetConfigFile(configPath)

	} else {

		// The default name of our YAML configuration file reflects the plugin name
		v.SetConfigName(pluginName)
		v.SetConfigType("yaml")

		// We search for the configuration file in both our global config directory and the current working directory
		v.AddConfigPath(".")
		v.AddConfigPath("\\etc\\directx-device-plugins")
	}

	// Attempt to parse our YAML configuration file if it exists
	if err := v.ReadInConfig(); err != nil {
		if _, ok := err.(viper.ConfigFileNotFoundError); ok {
			logger.Infow("Configuration file not found, using configuration values from environment variables")
		} else {
			return nil, err
		}
	}

	// Load the parsed configuration values into our struct
	c := &PluginConfig{}
	if err := v.Unmarshal(c); err != nil {
		return nil, err
	}

	// Enforce a minimum value of 1 for multitenancy
	if c.Multitenancy == 0 {
		c.Multitenancy = 1
	}

	// Append our default mounts to any user-supplied values
	c.AdditionalMounts = appendMounts(c.AdditionalMounts, mount.DefaultMounts)
	c.AdditionalMountsWow64 = appendMounts(c.AdditionalMountsWow64, mount.DefaultMountsWow64)

	// Log the parsed configuration values
	logger.Infow("Parsed configuration data", "config", c)

	return c, nil
}