feat: new openid connect authentication layer

internal/proxy/director/layer/authn/layer_options.go

@@ -0,0 +1,92 @@
+package authn
+
+import (
+	"reflect"
+	"time"
+
+	"forge.cadoles.com/cadoles/bouncer/internal/store"
+	"github.com/mitchellh/mapstructure"
+	"github.com/pkg/errors"
+)
+
+type LayerOptions struct {
+	MatchURLs []string       `mapstructure:"matchURLs"`
+	Headers   HeadersOptions `mapstructure:"headers"`
+}
+
+type HeadersOptions struct {
+	Rules []string `mapstructure:"rules"`
+}
+
+func DefaultLayerOptions() LayerOptions {
+	return LayerOptions{
+		MatchURLs: []string{"*"},
+		Headers: HeadersOptions{
+			Rules: []string{
+				"del_headers('Remote-*')",
+				"set_header('Remote-User', user.subject)",
+				`map(
+					toPairs(user.attrs), {
+						let name = replace(lower(string(get(#, 0))), '_', '-');
+						set_header(
+							'Remote-User-Attr-' + name, 
+							get(#, 1)
+						) 
+					})
+				`,
+			},
+		},
+	}
+}
+
+func fromStoreOptions(storeOptions store.LayerOptions) (*LayerOptions, error) {
+	layerOptions := DefaultLayerOptions()
+
+	if err := FromStoreOptions(storeOptions, &layerOptions); err != nil {
+		return nil, errors.WithStack(err)
+	}
+
+	return &layerOptions, nil
+}
+
+func FromStoreOptions(storeOptions store.LayerOptions, dest any) error {
+	config := mapstructure.DecoderConfig{
+		Result:     dest,
+		ZeroFields: true,
+		DecodeHook: mapstructure.ComposeDecodeHookFunc(
+			toDurationHookFunc(),
+		),
+	}
+
+	decoder, err := mapstructure.NewDecoder(&config)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	if err := decoder.Decode(storeOptions); err != nil {
+		return errors.WithStack(err)
+	}
+
+	return nil
+}
+
+func toDurationHookFunc() mapstructure.DecodeHookFunc {
+	return func(
+		f reflect.Type,
+		t reflect.Type,
+		data interface{}) (interface{}, error) {
+		if t != reflect.TypeOf(*new(time.Duration)) {
+			return data, nil
+		}
+
+		switch f.Kind() {
+		case reflect.String:
+			return time.ParseDuration(data.(string))
+		case reflect.Int64:
+			return time.Duration(data.(int64) * int64(time.Second)), nil
+		default:
+			return data, nil
+		}
+		// Convert it by parsing
+	}
+}