Add: prototype cleanup_media command

logs_collector/collector/management/commands/cleanup_media.py

@@ -0,0 +1,59 @@
+import os
+from django.core.management.base import BaseCommand
+from django.apps import apps
+from django.db.models import Q
+from django.conf import settings
+from django.db.models import FileField
+
+
+class Command(BaseCommand):
+    # HELP MESSAGE:
+    help_part1 = 'This command deletes all media files from'
+    help_part2 = 'the MEDIA_ROOT directory which are no longer referenced'
+    help_part3 = 'by any of the models from installed_apps'
+    help = f'{help_part1} {help_part2} {help_part3}'
+
+    def handle(self, *args, **options):
+        all_models = apps.get_models()
+        physical_files = set()
+        db_files = set()
+        # Get all files from the database
+        for model in all_models:
+            file_fields = []
+            filters = Q()
+            for f_ in model._meta.fields:
+                if isinstance(f_, FileField):
+                    file_fields.append(f_.name)
+                    is_null = {'{}__isnull'.format(f_.name): True}
+                    is_empty = {'{}__exact'.format(f_.name): ''}
+                    filters &= Q(**is_null) | Q(**is_empty)
+            # only retrieve the models which have non-empty,
+            # non-null file fields
+            if file_fields:
+                files = model.objects.exclude(filters).values_list(
+                    *file_fields,
+                    flat=True
+                ).distinct()
+                db_files.update(files)
+        # Get all files from the MEDIA_ROOT, recursively
+        media_root = getattr(settings, 'MEDIA_ROOT', None)
+        if media_root is not None:
+            for relative_root, dirs, files in os.walk(media_root):
+                for file_ in files:
+                    # Compute the relative file path to the media directory,
+                    # so it can be compared to the values from the db
+                    relative_file = os.path.join(
+                        os.path.relpath(relative_root, media_root), file_
+                    )
+                    physical_files.add(relative_file)
+        # Compute the difference and delete those files
+        deletables = physical_files - db_files
+        if deletables:
+            for file_ in deletables:
+                os.remove(os.path.join(media_root, file_))
+            # Bottom-up - delete all empty folders
+            for relative_root, dirs, files in os.walk(
+                    media_root, topdown=False):
+                for dir_ in dirs:
+                    if not os.listdir(os.path.join(relative_root, dir_)):
+                        os.rmdir(os.path.join(relative_root, dir_))