support for file's content64 (compat mode)

cmd/dkl-local-server/render-context.go

@@ -32,6 +32,8 @@ import (
 
 var cmdlineParam = restful.QueryParameter("cmdline", "Linux kernel cmdline addition")
 
+var b64 = base64.StdEncoding.WithPadding(base64.NoPadding)
+
 type renderContext struct {
 	Host      *localconfig.Host
 	SSLConfig *cfsslconfig.Config
@@ -102,11 +104,29 @@ func (ctx *renderContext) Config() (ba []byte, cfg *config.Config, err error) {
 		return
 	}
 
+	// log.Print("rendered config:\n", string(ba))
+
 	cfg = &config.Config{}
 	if err = yaml.Unmarshal(ba, cfg); err != nil {
 		return
 	}
 
+	// compatibility post-processing: decode all base64 content
+	for i := range cfg.Files {
+		file := &cfg.Files[i]
+
+		if file.Content64 != "" {
+			decoded, decodeErr := b64.DecodeString(file.Content64)
+			if decodeErr != nil {
+				err = fmt.Errorf("failed to decode file %s: %w", file.Path, decodeErr)
+				return
+			}
+
+			file.Content = string(decoded)
+			file.Content64 = ""
+		}
+	}
+
 	return
 }
 
@@ -189,6 +209,7 @@ func (ctx *renderContext) TemplateFuncs() map[string]any {
 			enc := base64.StdEncoding.WithPadding(base64.NoPadding)
 			return enc.EncodeToString([]byte(input))
 		},
+
 		"host_ip": func() (s string) {
 			return ctx.Host.IPs[0]
 		},