Add tool for downloading files from a backup.

astacus/manifest.py

@@ -8,6 +8,7 @@
 
 from astacus.common import ipc
 from astacus.common.rohmustorage import RohmuConfig, RohmuStorage
+from pathlib import Path
 
 import json
 import msgspec
@@ -48,6 +49,31 @@ def create_dump_parser(subparsers):
     p_dump.set_defaults(func=_run_dump)
 
 
+def create_download_files_parser(subparsers):
+    p_download_files = subparsers.add_parser("download-from", help="Download files from a backup manifest")
+    p_download_files.add_argument(
+        "manifest", type=str, help="Manifest object name (can be obtained by running manifest list)", required=True
+    )
+    p_download_files.add_argument("destination", type=str, help="Destination directory to download files to", required=True)
+    p_download_files.add_argument("--prefix", type=str, help="Prefix to filter files", required=True)
+    p_download_files.set_defaults(func=_run_download_files)
+
+
+def _run_download_files(args):
+    rohmu_storage = _create_rohmu_storage(args.config, args.storage)
+    manifest = rohmu_storage.download_json(args.manifest, ipc.BackupManifest)
+    destination = Path(args.destination)
+    for snapshot_result in manifest.snapshot_results:
+        assert snapshot_result.state
+        for snapshot_file in snapshot_result.state.files:
+            if args.prefix and not snapshot_file.relative_path.startswith(args.prefix):
+                continue
+
+            path = destination / snapshot_file.relative_path
+            path.parent.mkdir(parents=True, exist_ok=True)
+            rohmu_storage.download_hexdigest_to_path(snapshot_file.hexdigest, path)
+
+
 def _run_list(args):
     rohmu_storage = _create_rohmu_storage(args.config, args.storage)
     json_names = rohmu_storage.list_jsons()