feat(xo-server): provide zstd compression for VM export (#3878)

See #3773

packages/xo-server/src/api/backup-ng.js

@@ -11,7 +11,7 @@ export function createJob({ schedules, ...job }) {
 createJob.permission = 'admin'
 createJob.params = {
   compression: {
-    enum: ['', 'native'],
+    enum: ['', 'native', 'zstd'],
     optional: true,
   },
   mode: {
@@ -68,7 +68,7 @@ export function editJob(props) {
 editJob.permission = 'admin'
 editJob.params = {
   compression: {
-    enum: ['', 'native'],
+    enum: ['', 'native', 'zstd'],
     optional: true,
   },
   id: {

packages/xo-server/src/api/vm.js

@@ -706,7 +706,7 @@ export async function copy({ compress, name: nameLabel, sr, vm }) {
 
 copy.params = {
   compress: {
-    type: 'boolean',
+    type: ['boolean', 'string'],
     optional: true,
   },
   name: {
@@ -1132,7 +1132,7 @@ revert.resolve = {
 
 async function handleExport(req, res, { xapi, id, compress }) {
   const stream = await xapi.exportVm(id, {
-    compress: compress != null ? compress : true,
+    compress,
   })
   res.on('close', () => stream.cancel())
   // Remove the filename as it is already part of the URL.
@@ -1167,7 +1167,7 @@ async function export_({ vm, compress }) {
 
 export_.params = {
   vm: { type: 'string' },
-  compress: { type: 'boolean', optional: true },
+  compress: { type: ['boolean', 'string'], optional: true },
 }
 
 export_.resolve = {

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

@@ -539,7 +539,7 @@ export default class Xapi extends XapiBase {
     vmId,
     targetXapi,
     targetSrId,
-    { compress = true, nameLabel = undefined } = {}
+    { compress, nameLabel = undefined } = {}
   ) {
     // Fall back on local copy if possible.
     if (targetXapi === this) {
@@ -783,7 +783,7 @@ export default class Xapi extends XapiBase {
   // Returns a stream to the exported VM.
   @concurrency(2, stream => stream.then(stream => fromEvent(stream, 'end')))
   @cancelable
-  async exportVm($cancelToken, vmId, { compress = true } = {}) {
+  async exportVm($cancelToken, vmId, { compress = false } = {}) {
     const vm = this.getObject(vmId)
     const useSnapshot = isVmRunning(vm)
     const exportedVm = useSnapshot
@@ -793,7 +793,12 @@ export default class Xapi extends XapiBase {
     const promise = this.getResource($cancelToken, '/export/', {
       query: {
         ref: exportedVm.$ref,
-        use_compression: compress ? 'true' : 'false',
+        use_compression:
+          compress === 'zstd'
+            ? 'zstd'
+            : compress === true || compress === 'gzip'
+            ? 'true'
+            : 'false',
       },
       task: this.createTask('VM export', vm.name_label),
     }).catch(error => {

packages/xo-server/src/xapi/index.js.flow

@@ -93,7 +93,7 @@ declare export class Xapi {
   exportVm(
     cancelToken: mixed,
     vm: Vm,
-    options ?: Object
+    options?: { compress?: true | false | 'gzip' | 'zstd' }
   ): Promise<AugmentedReadable>;
   getObject(object: Id): XapiObject;
   importDeltaVm(data: DeltaVmImport, options: Object): Promise<{ vm: Vm }>;

packages/xo-server/src/xo-mixins/backups-ng/index.js

@@ -81,7 +81,7 @@ type SimpleIdPattern = {|
 
 export type BackupJob = {|
   ...$Exact<Job>,
-  compression?: 'native',
+  compression?: 'native' | 'zstd' | '',
   mode: Mode,
   remotes?: SimpleIdPattern,
   settings: $Dict<Settings>,
@@ -177,6 +177,9 @@ const isMetadataFile = (filename: string) => filename.endsWith('.json')
 const isVhd = (filename: string) => filename.endsWith('.vhd')
 const isXva = (filename: string) => filename.endsWith('.xva')
 
+const getJobCompression = ({ compression: c }) =>
+  c === undefined || c === '' ? false : c === 'native' ? 'gzip' : 'zstd'
+
 const listReplicatedVms = (
   xapi: Xapi,
   scheduleId: string,
@@ -1119,7 +1122,7 @@ export default class BackupNg {
           parentId: taskId,
         },
         xapi.exportVm($cancelToken, snapshot, {
-          compress: job.compression === 'native',
+          compress: getJobCompression(job),
         })
       )
       const exportTask = xva.task