backups: When restoring, only list apps included in backup

Signed-off-by: James Valleroy <jvalleroy@mailbox.org>
Reviewed-by: Joseph Nuthalapati <njoseph@thoughtworks.com>

actions/backups

@@ -25,6 +25,7 @@ import glob
 import json
 import os
 import subprocess
+import tarfile
 
 REPOSITORY = '/var/lib/freedombox/borgbackup'
 
@@ -62,6 +63,12 @@ def parse_arguments():
     list_exports.add_argument('--location', required=True,
                               help='location to check')
 
+    get_export_apps = subparsers.add_parser(
+        'get-export-apps',
+        help='Get list of apps included in exported archive file')
+    get_export_apps.add_argument(
+        '--filename', help='Tarball file name', required=True)
+
     restore = subparsers.add_parser(
         'restore', help='Restore files from an exported archive')
     restore.add_argument('--filename', help='Tarball file name', required=True)
@@ -144,6 +151,23 @@ def subcommand_list_exports(arguments):
     print(json.dumps(exports))
 
 
+def subcommand_get_export_apps(arguments):
+    """Get list of apps included in exported archive file."""
+    manifest = None
+    with tarfile.open(arguments.filename) as t:
+        filenames = t.getnames()
+        for name in filenames:
+            if 'var/lib/plinth/backups-manifests/' in name \
+               and name.endswith('.json'):
+                manifest_data = t.extractfile(name).read()
+                manifest = json.loads(manifest_data)
+                break
+
+    if manifest:
+        for app in manifest:
+            print(app['name'])
+
+
 def subcommand_restore(arguments):
     """Restore files from an exported archive."""
     prev_dir = os.getcwd()

plinth/modules/backups/__init__.py

@@ -140,7 +140,7 @@ def get_export_files():
     return export_files
 
 
-def _find_exported_archive(disk_label, archive_name):
+def find_exported_archive(disk_label, archive_name):
     """Return the full path for the exported archive file."""
     path = None
     locations = get_export_locations()
@@ -155,9 +155,16 @@ def _find_exported_archive(disk_label, archive_name):
     return path
 
 
+def get_export_apps(filename):
+    """Get list of apps included in exported archive file."""
+    output = actions.superuser_run(
+        'backups', ['get-export-apps', '--filename', filename])
+    return output.splitlines()
+
+
 def restore_exported(label, name, apps=None):
     """Restore files from exported backup archive."""
-    filename = _find_exported_archive(label, name)
+    filename = find_exported_archive(label, name)
     if filename:
         # TODO: Use backups API.
         actions.superuser_run(

plinth/modules/backups/forms.py

@@ -67,9 +67,8 @@ class RestoreForm(forms.Form):
 
     def __init__(self, *args, **kwargs):
         """Initialize the form with selectable apps."""
+        apps = kwargs.pop('apps')
         super().__init__(*args, **kwargs)
-        apps = _list_of_all_apps_for_backup()
-        # TODO: Only list apps included in the backup file.
         self.fields['selected_apps'].choices = [
             (app[0], app[1].name) for app in apps]
         self.fields['selected_apps'].initial = [app[0] for app in apps]

plinth/modules/backups/views.py

@@ -30,6 +30,7 @@ from django.views.generic import FormView, TemplateView
 from urllib.parse import unquote
 
 from plinth.modules import backups
+from . import find_exported_archive, get_export_apps
 from .backups import _list_of_all_apps_for_backup
 from .forms import CreateArchiveForm, ExportArchiveForm, RestoreForm
 
@@ -133,6 +134,31 @@ class RestoreView(SuccessMessageMixin, FormView):
     success_url = reverse_lazy('backups:index')
     success_message = _('Restored files from backup.')
 
+    def collect_data(self, label, name):
+        """Save some data used to instantiate the form."""
+        self.label = unquote(label)
+        self.name = unquote(name)
+        self.filename = find_exported_archive(self.label, self.name)
+        self.installed_apps = _list_of_all_apps_for_backup()
+        self.included_apps = get_export_apps(self.filename)
+
+    def get(self, request, *args, **kwargs):
+        """Save request parameters for later."""
+        self.collect_data(kwargs['label'], kwargs['name'])
+        return super().get(request, *args, **kwargs)
+
+    def post(self, request, *args, **kwargs):
+        """Save request parameters for later."""
+        self.collect_data(kwargs['label'], kwargs['name'])
+        return super().post(request, *args, **kwargs)
+
+    def get_form_kwargs(self):
+        """Pass additional keyword args for instantiating the form."""
+        kwargs = super().get_form_kwargs()
+        kwargs['apps'] = [
+            x for x in self.installed_apps if x[0] in self.included_apps]
+        return kwargs
+
     def get_context_data(self, **kwargs):
         """Return additional context for rendering the template."""
         context = super().get_context_data(**kwargs)