fix(internal/config): properly use a flat data structure for reading …

…and storing driver config.

Convert it in `config.Driverer` to the exposed structure with driver.Type resolved to its interface.

Signed-off-by: Federico Di Pierro <[email protected]>

internal/config/config.go

@@ -51,7 +51,7 @@ var (
 	// DefaultRegistryCredentialConfPath is the default path for the credential store configuration file.
 	DefaultRegistryCredentialConfPath = filepath.Join(config.Dir(), "config.json")
 	// DefaultDriver is the default config for the falcosecurity organization.
-	DefaultDriver Driver
+	DefaultDriver driver
 
 	// Useful regexps for parsing.
 
@@ -116,16 +116,6 @@ const (
 
 	// DriverKey is the Viper key for driver structure.
 	DriverKey = "driver"
-	// DriverTypeKey is the Viper key for the driver type.
-	DriverTypeKey = "driver.type"
-	// DriverVersionKey is the Viper key for the driver version.
-	DriverVersionKey = "driver.version"
-	// DriverReposKey is the Viper key for the driver repositories.
-	DriverReposKey = "driver.repos"
-	// DriverNameKey is the Viper key for the driver name.
-	DriverNameKey = "driver.name"
-	// DriverHostRootKey is the Viper key for the driver host root.
-	DriverHostRootKey = "driver.hostRoot"
 )
 
 // Index represents a configured index.
@@ -175,7 +165,16 @@ type Install struct {
 	NoVerify      bool     `mapstructure:"noVerify"`
 }
 
-// Driver represents a configured driver.
+// driver represents the internal driver configuration (with Type string).
+type driver struct {
+	Type     string   `mapstructure:"type"`
+	Name     string   `mapstructure:"name"`
+	Repos    []string `mapstructure:"repos"`
+	Version  string   `mapstructure:"version"`
+	HostRoot string   `mapstructure:"hostRoot"`
+}
+
+// Driver represents the resolved driver configuration, exposed to be consumed.
 type Driver struct {
 	Type     drivertype.DriverType `mapstructure:"type"`
 	Name     string                `mapstructure:"name"`
@@ -194,9 +193,8 @@ func init() {
 		Name: "falcosecurity",
 		URL:  "https://falcosecurity.github.io/falcoctl/index.yaml",
 	}
-	kmodType, _ := drivertype.Parse(drivertype.TypeKmod)
-	DefaultDriver = Driver{
-		Type:     kmodType,
+	DefaultDriver = driver{
+		Type:     drivertype.TypeKmod,
 		Name:     "falco",
 		Repos:    []string{"https://download.falco.org/driver"},
 		Version:  "",
@@ -492,33 +490,6 @@ func gcpAuthListHookFunc() mapstructure.DecodeHookFuncType {
 	}
 }
 
-// driverHookFunc returns a DecodeHookFunc that converts
-// strings to string slices, when the target type is DotSeparatedStringList.
-// when passed as env should be in the following format:
-// "registry;registry1".
-// Moreover, it also converts driver.type string to drivertype.Type.
-func driverHookFunc() mapstructure.DecodeHookFuncType {
-	return func(f reflect.Type, t reflect.Type, data interface{}) (interface{}, error) {
-		if f.Kind() != reflect.Struct && f.Kind() != reflect.String {
-			return data, nil
-		}
-
-		if t != reflect.TypeOf(Driver{}) && t != reflect.TypeOf((*drivertype.DriverType)(nil)).Elem() {
-			return data, fmt.Errorf("unable to decode data since destination variable is not of type %T nor DriverType", Driver{})
-		}
-
-		// Format/decode/parse the data and return the new value
-		switch f.Kind() {
-		case reflect.String:
-			return drivertype.Parse(data.(string))
-		case reflect.Struct:
-			return data, nil
-		default:
-			return nil, nil
-		}
-	}
-}
-
 // Follower retrieves the follower section of the config file.
 func Follower() (Follow, error) {
 	// with Follow we can just use nested keys.
@@ -565,10 +536,13 @@ func Installer() (Install, error) {
 
 // Driverer retrieves the driver section of the config file.
 func Driverer() (Driver, error) {
-	var drvCfg Driver
+	var (
+		drvCfg         driver
+		resolvedDrvCfg Driver
+	)
 
-	if err := viper.UnmarshalKey(DriverKey, &drvCfg, viper.DecodeHook(driverHookFunc())); err != nil {
-		return drvCfg, fmt.Errorf("unable to get driver: %w", err)
+	if err := viper.UnmarshalKey(DriverKey, &drvCfg); err != nil {
+		return resolvedDrvCfg, fmt.Errorf("unable to get driver: %w", err)
 	}
 
 	// Try to load it automatically from /usr/src sub folders,
@@ -593,7 +567,16 @@ func Driverer() (Driver, error) {
 		}
 	}
 
-	return drvCfg, nil
+	drvType, err := drivertype.Parse(drvCfg.Type)
+	if err != nil {
+		return resolvedDrvCfg, err
+	}
+	resolvedDrvCfg.Type = drvType
+	resolvedDrvCfg.Name = drvCfg.Name
+	resolvedDrvCfg.HostRoot = drvCfg.HostRoot
+	resolvedDrvCfg.Version = drvCfg.Version
+	resolvedDrvCfg.Repos = drvCfg.Repos
+	return resolvedDrvCfg, nil
 }
 
 // StoreDriver stores a driver conf in config file.