dbbackup --clean not working

[oliverbienert]

Current Situation

The commandline switch -c/--clean does not work when issueing a backup:

python manage.py dbbackup -c -q -z.

Nothing get deleted. Setting DBBACKUP_CLEANUP_KEEP to another value (e.g. 5) does not help.
However, issueing a media backup:

python manage.py mediabackup -c -q -z

works as expected, only the last 10 files are being kept.
Here are my filename templates:

DBBACKUP_FILENAME_TEMPLATE = "db-{datetime}.{extension}"
DBBACKUP_MEDIA_FILENAME_TEMPLATE = "media-{datetime}.{extension}"

Tested with version 4.3 and 5.0.

The logs do not help:

2025-10-09 14:53:18,102 dbbackup.command INFO     Backing Up Database: bze3_portal_dev
2025-10-09 14:53:18,102 dbbackup.command DEBUG     pg_dump --dbname=postgresql://postgres@localhost/bze3_portal_dev --format=custom 
2025-10-09 14:53:18,208 dbbackup.command DEBUG    Backup size: 115.6 KiB
2025-10-09 14:53:18,208 dbbackup.command INFO     Writing file to db-2025-10-09-145318.psql.bin.gz

Proposed Actions

No response

System Information

Occurs on both my development and my production system: Ubuntu 24.04
Django 5.2.1
Postgresql 16

[oliverbienert]

Sorry for the noise:
My template filename {databasename} prefix differed from the database key. When it starts with 'default', as my settings in DATABASES and DBBACKUP_CONNECTORS, everything works as expected.

[UDAR-TomH]

I'd argue that this issue should be re-opened. This looks like an undocumented change to how the package works.

[oliverbienert]

Perhaps the documentation should state more clearly that the database key(s) from the Django setting DATABASES is the crucial setting here. It is used in different places (DBBACKUP_DATABASES, DBBACKUP_CONNECTORS), but I personally think the docs are sufficient here.
As for the Clean-up: The filter looks for the {databasename} when to figure whether a file should deleted/kept. That means that the substitute template {databasename} should be part of DBBACKUP_FILENAME_TEMPLATE, especially when dealing with more than one database, otherwise the filter wouldn't find the files to be handled by the clean up. That's the part that was a bit unclear to me.

By the way, I even backup a non django database that I handle separately in code. Great!