backups: Simplify export of backup archive files

- Allow selection of Root Filesystem or any removable drive.
- Export to FreedomBox-backups folder in selection location.
- Handle export location without / at the end

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

actions/backups

@@ -104,6 +104,10 @@ def subcommand_extract(arguments):
 
 def subcommand_export(arguments):
     """Export archive contents as tarball."""
+    path = os.path.dirname(arguments.filename)
+    if not os.path.exists(path):
+        os.makedirs(path)
+
     subprocess.run([
         'borg', 'export-tar', REPOSITORY + '::' + arguments.name,
         arguments.filename

plinth/modules/backups/__init__.py

@@ -24,6 +24,7 @@ from django.utils.translation import ugettext_lazy as _
 
 from plinth import actions
 from plinth.menu import main_menu
+from plinth.modules import udiskie
 
 version = 1
 
@@ -80,6 +81,22 @@ def extract_archive(name, destination):
         'backups', ['extract', '--name', name, '--destination', destination])
 
 
-def export_archive(name, filename):
+def export_archive(name, location):
+    if location[-1] != '/':
+        location += '/'
+    filename = location + 'FreedomBox-backups/' + name + '.tar.gz'
     actions.superuser_run('backups',
                           ['export', '--name', name, '--filename', filename])
+
+
+def get_export_locations():
+    """Return a list of storage locations for exported backup archives."""
+    locations = [('/var/lib/freedombox/', _('Root Filesystem'))]
+    if udiskie.is_running():
+        devices = udiskie.udisks2.list_devices()
+        for device in devices:
+            if 'mount_points' in device and len(device['mount_points']) > 0:
+                name = device['label'] or device['device']
+                locations.append((device['mount_points'][0], name))
+
+    return locations

plinth/modules/backups/forms.py

@@ -22,6 +22,8 @@ from django import forms
 from django.core import validators
 from django.utils.translation import ugettext_lazy as _
 
+from . import get_export_locations
+
 
 class CreateArchiveForm(forms.Form):
     name = forms.CharField(
@@ -42,6 +44,12 @@ class ExtractArchiveForm(forms.Form):
 
 
 class ExportArchiveForm(forms.Form):
-    filename = forms.CharField(
-        label=_('Exported filename'), strip=True,
-        help_text=_('Name for the tar file exported from the archive.'))
+    disk = forms.ChoiceField(
+        label=_('Disk'), widget=forms.RadioSelect(),
+        help_text=_('Disk or removable storage where the backup archive will '
+                    'be saved.'))
+
+    def __init__(self, *args, **kwargs):
+        """Initialize the form with disk choices."""
+        super().__init__(*args, **kwargs)
+        self.fields['disk'].choices = get_export_locations()

plinth/modules/backups/views.py

@@ -132,5 +132,5 @@ class ExportArchiveView(SuccessMessageMixin, FormView):
     def form_valid(self, form):
         """Create the archive on valid form submission."""
         backups.export_archive(self.kwargs['name'],
-                               form.cleaned_data['filename'])
+                               form.cleaned_data['disk'])
         return super().form_valid(form)