Question Best way to include persistent Docker data in Plesk Backups?

[propz]

Server operating system version

Debian 12

Plesk version and microupdate number

18.0.68

Hi guys,

I managed to self host a couple of Docker Images and it's running fine.
However, I would like Plesk to backup the persistent data from the volume mapping and this seems quite tricky.

This is an exmaple on how I configured my Selfhosted Vaultwarden Server:

1. Create Subdomain: vault.domain.com
2. Create Container for Vaultwarden Server and fill in needed ENV Variables
3. Volume mapping:
   - Host: /var/www/vhosts/domain.com/vault.domain.com/
   - Container: /data
4. Docker Container can't write to the specified folder, so I need to change the folder owner to user id 1000 (AI gave me the answer)
   This is how the permissions look like:
   
   

   drwxr-xr-x  2     1000 psaadm    4096 Apr 23 23:29 attachments
   -rw-r--r--  1     1000 psaadm  806912 Apr 23 23:34 db.sqlite3
   -rw-r--r--  1     1000 psaadm   32768 Apr 23 23:37 db.sqlite3-shm
   -rw-r--r--  1     1000 psaadm   32992 Apr 23 23:37 db.sqlite3-wal
   drwxr-xr-x  2     1000 psaadm    4096 Apr 23 23:47 icon_cache
   -rw-r--r--  1     1000 psaadm     464 Apr 23 23:29 index.html
   -rw-r--r--  1     1000 psaadm    1675 Apr 23 23:29 rsa_key.pem
   drwxr-xr-x  2     1000 psaadm    4096 Apr 23 23:29 sends
   drwxr-xr-x  2     1000 psaadm    4096 Apr 23 23:29 tmp

   
   
5. Map Container port to a free server port without exposing it (e.g. 12345)
6. Configure nginx to work as proxy for the subdomain (turn off apache completely)
   
   

   location / {
       proxy_pass http://localhost:12345; # Proxy requests to your application
       proxy_set_header Host $host;
       proxy_set_header X-Real-IP $remote_addr;
       proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
       proxy_set_header X-Forwarded-Proto $scheme;
   }

Done, now I can access vaultwarden via vault.domain.com.
So far so good.

But: the reason why I mapped the volume to the subdomain folder is because I want Plesk to include the persistent data in the normal backup. But that doesn't work because of the changed permissions...

Warning: Subscription "domain.com"
Not all the data from /var/www/vhosts/domain.com was backed up successfully:
  vault.domain.com: Cannot open: Permission denied
  vault.domain.com/db.sqlite3: Cannot stat: Permission denied.
  [...]

So: How can I achieve this?
What's the right way to include the persistent data in the backup?