fix(xo-server/disk.exportContent): better HTTP properties handling

packages/xo-server/src/api/disk.mjs

@@ -93,10 +93,18 @@ async function handleExportContent(req, res, { filename, format, vdi }) {
       : await vdi.$exportContent({ format: VDI_FORMAT_VHD })
   req.on('close', () => stream.destroy())
 
-  // Remove the filename as it is already part of the URL.
-  stream.headers['content-disposition'] = 'attachment'
+  // stream can be an HTTP response, in this case, extract interesting data
+  const { headers = {}, length, statusCode = 200, statusMessage = 'OK' } = stream
 
-  res.writeHead(stream.statusCode, stream.statusMessage != null ? stream.statusMessage : '', stream.headers)
+  // Set the correct disposition
+  headers['content-disposition'] = 'attachment'
+
+  // expose the stream length if known
+  if (headers['content-length'] === undefined && length !== undefined) {
+    headers['content-length'] = length
+  }
+
+  res.writeHead(statusCode, statusMessage != null ? statusMessage : '', headers)
   pipeline(stream, res, error => {
     if (error != null) {
       log.warn('disk.exportContent', { error })

packages/xo-server/src/xapi/index.mjs

@@ -1118,13 +1118,6 @@ export default class Xapi extends XapiBase {
       vhdResult = await this.VDI_exportContent(vdi.$ref, params)
       return vhdResult
     })
-    // callers expect the stream to be an HTTP response.
-    vmdkStream.headers = {
-      ...vhdResult.headers,
-      'content-type': 'application/x-vmdk',
-    }
-    vmdkStream.statusCode = vhdResult.statusCode
-    vmdkStream.statusMessage = vhdResult.statusMessage
     return vmdkStream
   }