feat(xo-server/api): backupNg.{,un}mountPartition (#7176)

Manual method to mount a backup partition on the XOA.

@vates/multi-key-map/.USAGE.md

@@ -17,4 +17,14 @@ map.get(['foo', 'bar']) // 2
 map.get(['bar', 'foo']) // 3
 map.get([OBJ]) // 4
 map.get([{}]) // undefined
+
+map.delete([])
+
+for (const [key, value] of map.entries() {
+  console.log(key, value)
+}
+
+for (const  value of map.values()) {
+  console.log(value)
+}
 ```

@vates/multi-key-map/README.md

@@ -35,6 +35,16 @@ map.get(['foo', 'bar']) // 2
 map.get(['bar', 'foo']) // 3
 map.get([OBJ]) // 4
 map.get([{}]) // undefined
+
+map.delete([])
+
+for (const [key, value] of map.entries() {
+  console.log(key, value)
+}
+
+for (const  value of map.values()) {
+  console.log(value)
+}
 ```
 
 ## Contributions

@vates/multi-key-map/index.js

@@ -36,6 +36,23 @@ function del(node, i, keys) {
   return node
 }
 
+function* entries(node, key) {
+  if (node !== undefined) {
+    if (node instanceof Node) {
+      const { value } = node
+      if (value !== undefined) {
+        yield [key, node.value]
+      }
+
+      for (const [childKey, child] of node.children.entries()) {
+        yield* entries(child, key.concat(childKey))
+      }
+    } else {
+      yield [key, node]
+    }
+  }
+}
+
 function get(node, i, keys) {
   return i === keys.length
     ? node instanceof Node
@@ -69,6 +86,22 @@ function set(node, i, keys, value) {
   return node
 }
 
+function* values(node) {
+  if (node !== undefined) {
+    if (node instanceof Node) {
+      const { value } = node
+      if (value !== undefined) {
+        yield node.value
+      }
+      for (const child of node.children.values()) {
+        yield* values(child)
+      }
+    } else {
+      yield node
+    }
+  }
+}
+
 exports.MultiKeyMap = class MultiKeyMap {
   constructor() {
     // each node is either a value or a Node if it contains children
@@ -79,6 +112,10 @@ exports.MultiKeyMap = class MultiKeyMap {
     this._root = del(this._root, 0, keys)
   }
 
+  entries() {
+    return entries(this._root, [])
+  }
+
   get(keys) {
     return get(this._root, 0, keys)
   }
@@ -86,4 +123,8 @@ exports.MultiKeyMap = class MultiKeyMap {
   set(keys, value) {
     this._root = set(this._root, 0, keys, value)
   }
+
+  values() {
+    return values(this._root)
+  }
 }

@vates/multi-key-map/index.test.js

@@ -19,7 +19,7 @@ describe('MultiKeyMap', () => {
       // reverse composite key
       ['bar', 'foo'],
     ]
-    const values = keys.map(() => ({}))
+    const values = keys.map(() => Math.random())
 
     // set all values first to make sure they are all stored and not only the
     // last one
@@ -27,6 +27,12 @@ describe('MultiKeyMap', () => {
       map.set(key, values[i])
     })
 
+    assert.deepEqual(
+      Array.from(map.entries()),
+      keys.map((key, i) => [key, values[i]])
+    )
+    assert.deepEqual(Array.from(map.values()), values)
+
     keys.forEach((key, i) => {
       // copy the key to make sure the array itself is not the key
       assert.strictEqual(map.get(key.slice()), values[i])

CHANGELOG.unreleased.md

@@ -14,6 +14,7 @@
 - [VM Creation] Added ISO option in new VM form when creating from template with a disk [#3464](https://github.com/vatesfr/xen-orchestra/issues/3464) (PR [#7166](https://github.com/vatesfr/xen-orchestra/pull/7166))
 - [REST API] `tags` property can be updated (PR [#7196](https://github.com/vatesfr/xen-orchestra/pull/7196))
 - [REST API] A VDI export can now be imported in an existing VDI (PR [#7199](https://github.com/vatesfr/xen-orchestra/pull/7199))
+- [File Restore] API method `backupNg.mountPartition` to manually mount a backup disk on the XOA
 
 ### Bug fixes
 
@@ -40,6 +41,7 @@
 
 <!--packages-start-->
 
+- @vates/multi-key-map minor
 - @vates/nbd-client patch
 - @xen-orchestra/backups minor
 - @xen-orchestra/cr-seed-cli major
@@ -51,5 +53,6 @@
 - xo-server-netbox minor
 - xo-vmdk-to-vhd patch
 - xo-web minor
+- xo-server minor
 
 <!--packages-end-->

packages/xo-server/config.toml

@@ -76,6 +76,8 @@ defaultSignInPage = '/signin'
 throttlingDelay = '2 seconds'
 
 [backups]
+autoUnmountPartitionDelay = '24h'
+
 disableMergeWorker = false
 
 # Mode to use for newly created backup directories

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

@@ -380,3 +380,47 @@ fetchFiles.params = {
     type: 'string',
   },
 }
+
+export function listMountedPartitions() {
+  return this.listMountedPartitions()
+}
+
+listMountedPartitions.permission = 'admin'
+
+export function mountPartition({ remote, disk, partition }) {
+  return this.mountPartition(remote, disk, partition)
+}
+
+mountPartition.permission = 'admin'
+
+mountPartition.params = {
+  disk: {
+    type: 'string',
+  },
+  partition: {
+    optional: true,
+    type: 'string',
+  },
+  remote: {
+    type: 'string',
+  },
+}
+
+export function unmountPartition({ remote, disk, partition }) {
+  return this.unmountPartition(remote, disk, partition)
+}
+
+unmountPartition.permission = 'admin'
+
+unmountPartition.params = {
+  disk: {
+    type: 'string',
+  },
+  partition: {
+    optional: true,
+    type: 'string',
+  },
+  remote: {
+    type: 'string',
+  },
+}

packages/xo-server/src/xo-mixins/file-restore-ng.mjs

@@ -1,5 +1,12 @@
 import Disposable from 'promise-toolbox/Disposable'
+import isPromise from 'promise-toolbox/isPromise'
+import { asyncEach } from '@vates/async-each'
+import { createLogger } from '@xen-orchestra/log'
+import { decorateWith } from '@vates/decorate-with'
 import { execa } from 'execa'
+import { MultiKeyMap } from '@vates/multi-key-map'
+
+const { warn } = createLogger('xo:mixins:file-restore-ng')
 
 // - [x] list partitions
 // - [x] list files in a partition
@@ -22,6 +29,8 @@ import { execa } from 'execa'
 //       - [ ] getMountedPartitions
 //       - [ ] unmountPartition
 export default class BackupNgFileRestore {
+  #mounts = new MultiKeyMap()
+
   constructor(app) {
     this._app = app
 
@@ -31,6 +40,16 @@ export default class BackupNgFileRestore {
       await Promise.all([execa('losetup', ['-D']), execa('vgchange', ['-an'])])
       await execa('pvscan', ['--cache'])
     })
+
+    app.hooks.on('stop', () =>
+      asyncEach(
+        this.#mounts.values(),
+        async pDisposable => {
+          await (await pDisposable).dispose()
+        },
+        { stopOnError: false }
+      )
+    )
   }
 
   async fetchBackupNgPartitionFiles(remoteId, diskId, partitionId, paths, format) {
@@ -108,4 +127,77 @@ export default class BackupNgFileRestore {
           adapter.listPartitionFiles(diskId, partitionId, path)
         )
   }
+
+  listMountedPartitions() {
+    const mounts = []
+    for (const [key, disposable] of this.#mounts.entries()) {
+      if (!isPromise(disposable)) {
+        const [remote, disk, partition] = key
+        mounts.push({ remote, disk, partition, path: disposable.value })
+      }
+    }
+    return mounts
+  }
+
+  @decorateWith(Disposable.factory)
+  *_mountPartition(remoteId, diskId, partitionId) {
+    const adapter = yield this._app.getBackupsRemoteAdapter(remoteId)
+
+    // yield(2) the disposable to use it
+    // yield(1) the value to make it available
+    yield yield adapter.getPartition(diskId, partitionId)
+  }
+
+  async mountPartition(remoteId, diskId, partitionId) {
+    const mounts = this.#mounts
+    const key = [remoteId, diskId, partitionId]
+
+    let pDisposable = mounts.get(key)
+    if (pDisposable !== undefined) {
+      return (await pDisposable).value
+    }
+
+    pDisposable = this._mountPartition(remoteId, diskId, partitionId)
+    mounts.set(key, pDisposable)
+    pDisposable.catch(() => mounts.delete(key))
+
+    const disposable = await pDisposable
+
+    // replace the promise by it's value so that it can be used directly in
+    // listMountedPartitions without breaking other uses
+    mounts.set(key, disposable)
+
+    const delay = await this._app.config.getDuration('backups.autoUnmountPartitionDelay')
+    if (delay !== 0) {
+      const dispose = disposable.dispose.bind(disposable)
+
+      const handle = setTimeout(
+        () =>
+          disposable.dispose().catch(error => {
+            warn('unmounting partition', { error })
+          }),
+        delay
+      )
+      disposable.dispose = () => {
+        clearTimeout(handle)
+        return dispose()
+      }
+    }
+
+    return disposable.value
+  }
+
+  async unmountPartition(remoteId, diskId, partitionId) {
+    const mounts = this.#mounts
+    const key = [remoteId, diskId, partitionId]
+
+    const pDisposable = mounts.get(key)
+    if (pDisposable === undefined) {
+      return
+    }
+
+    mounts.delete(key)
+
+    await (await pDisposable).dispose()
+  }
 }