feat(backups/XO metadata): transfer binary config in base64

@xen-orchestra/backups/RestoreMetadataBackup.mjs

@@ -21,7 +21,12 @@ export class RestoreMetadataBackup {
       })
     } else {
       const metadata = JSON.parse(await handler.readFile(join(backupId, 'metadata.json')))
-      return String(await handler.readFile(resolve(backupId, metadata.data ?? 'data.json')))
+      const dataFileName = resolve(backupId, metadata.data ?? 'data.json')
+      const data = await handler.readFile(dataFileName)
+
+      // if data is JSON, sent it as a plain string, otherwise, consider the data as binary and encode it
+      const isJson = dataFileName.endsWith('.json')
+      return isJson ? data.toString() : { encoding: 'base64', data: data.toString('base64') }
     }
   }
 }

@xen-orchestra/backups/_runners/_XoMetadataBackup.mjs

@@ -22,7 +22,13 @@ export class XoMetadataBackup {
     const dir = `${scheduleDir}/${formatFilenameDate(timestamp)}`
 
     const data = job.xoMetadata
-    const dataBaseName = './data.json'
+    let dataBaseName = './data'
+
+    // JSON data is sent as plain string, binary data is sent as an object with `data` and `encoding properties
+    const isJson = typeof data === 'string'
+    if (isJson) {
+      dataBaseName += '.json'
+    }
 
     const metadata = JSON.stringify(
       {
@@ -54,7 +60,7 @@ export class XoMetadataBackup {
           async () => {
             const handler = adapter.handler
             const dirMode = this._config.dirMode
-            await handler.outputFile(dataFileName, data, { dirMode })
+            await handler.outputFile(dataFileName, isJson ? data : Buffer.from(data.data, data.encoding), { dirMode })
             await handler.outputFile(metaDataFileName, metadata, {
               dirMode,
             })

packages/xo-server/src/xo-mixins/metadata-backups.mjs

@@ -51,7 +51,11 @@ export default class metadataBackup {
     }
 
     const app = this._app
-    job.xoMetadata = job.xoMetadata ? await app.exportConfig() : undefined
+
+    if (job.xoMetadata) {
+      const config = await app.exportConfig()
+      job.xoMetadata = typeof config === 'string' ? config : { encoding: 'base64', data: config.toString('base64') }
+    }
 
     const remoteIds = unboxIdsFromPattern(job.remotes)
     const proxyId = job.proxy
@@ -325,7 +329,8 @@ export default class metadataBackup {
     const onLog = async log => {
       if (type === 'xoConfig' && localTaskIds[log.taskId] === rootTaskId && log.status === 'success') {
         try {
-          await app.importConfig(log.result)
+          const { result } = log
+          await app.importConfig(typeof result === 'string' ? result : Buffer.from(result.data, result.encoding))
 
           // don't log the XO config
           log.result = undefined