feat(backups): add restore_snapshot and restore_service_from_snapshot

selfprivacy_api/backup/__init__.py

@@ -4,12 +4,14 @@ from selfprivacy_api.models.backup.snapshot import Snapshot
 
 from selfprivacy_api.utils.singleton_metaclass import SingletonMetaclass
 
+from selfprivacy_api.services import get_service_by_id
 from selfprivacy_api.services.service import Service
+
 from selfprivacy_api.backup.providers.provider import AbstractBackupProvider
 from selfprivacy_api.backup.providers import get_provider
 from selfprivacy_api.graphql.queries.providers import BackupProvider
 
-
+# Singleton has a property of being persistent between tests. I don't know what to do with this yet
 # class Backups(metaclass=SingletonMetaclass):
 class Backups:
     """A singleton controller for backups"""
@@ -63,3 +65,15 @@ class Backups:
         repo_name = service.get_id()
 
         return self.provider.backuper.get_snapshots(repo_name)
+
+    def restore_service_from_snapshot(self, service: Service, snapshot_id: str):
+        repo_name = service.get_id()
+        folder = service.get_location()
+
+        self.provider.backuper.restore_from_backup(repo_name, snapshot_id, folder)
+
+    # Our dummy service is not yet globally registered so this is not testable yet
+    def restore_snapshot(self, snapshot: Snapshot):
+        self.restore_service_from_snapshot(
+            get_service_by_id(snapshot.service_name), snapshot.id
+        )

selfprivacy_api/backup/backuper.py

@@ -20,3 +20,8 @@ class AbstractBackuper(ABC):
     @abstractmethod
     def init(self, repo_name):
         raise NotImplementedError
+
+    @abstractmethod
+    def restore_from_backup(self, repo_name: str, snapshot_id: str, folder: str):
+        """Restore a target folder using a snapshot"""
+        raise NotImplementedError

selfprivacy_api/backup/restic_backuper.py

@@ -98,7 +98,13 @@ class ResticBackuper(AbstractBackuper):
             repo_name, "restore", snapshot_id, "--target", folder
         )
 
-        subprocess.run(restore_command, shell=False)
+        with subprocess.Popen(
+            restore_command, stdout=subprocess.PIPE, shell=False
+        ) as handle:
+
+            output = handle.communicate()[0].decode("utf-8")
+            if "restored" not in output:
+                raise ValueError("cannot restore a snapshot: " + output)
 
     def _load_snapshots(self, repo_name) -> object:
         """