[Plex - mount cifs] Unable to apply new capability set

[Marnalas]

Problem/Motivation

First of all, thank you for your work. I am a very grateful user of Samba NAS and Plex Media Server with NAS addons.

I am running in an issue with Plex Media Server with NAS. The addon can't mount a network disk anymore. It worked well before. As far as I can tell, this problem started appearing with the Core 2021.2.3.

Expected behavior

[12:45:00] INFO: Starting the Plex Media Server...
[12:45:00] INFO: Network Disks mounting.. //192.168**/pms
[12:45:00] INFO: Mount //192.168**/pms
[12:45:00] INFO: Success!

Actual behavior

[12:45:00] INFO: Starting the Plex Media Server...
[12:45:00] INFO: Network Disks mounting.. //192.168**/pms
[12:45:00] INFO: Mount //192.168**/pms
mount error(13): Permission denied
Refer to the mount.cifs(8) manual page (e.g. man mount.cifs)
[12:45:00] WARNING: Protection mode is ON. Unable to mount external drivers!

Steps to reproduce

Start the addon with a networkdisks set up. The //192.168**/pms is mounted using your SambaNAS addon.

claim_code: **
webtools: true
networkdisks: - //192.168**/pms
cifsusername: **
cifspassword: **
cifsversion: '3.0'

Proposed changes

I used docker exec -it addon_**_plex /bin/bash to investigate the problem:

• The folder /192.168**/pms is correctly created and the permissions are correctly set up.
• I tried to execute the mount request and ran into the same problem, even when trying to use a different directory.

The same request (mkdir -p /192.168**/pms && chown -R root:root /192.168**/pms && mount -t cifs -o username='**',password='**',vers=3.0 //192.168**/pms /192.168**/pms) runs perfectly in the homeassistant container. This makes me think that the problem comes from the docker container running the addon missing some permissions or capabilities.

Same as with the Samba NAS addon problem you solved by adding a apparmor.txt, my guess would be to add something similar so the mount capability is added to the docker container running plex.

EDIT : I tried this in a fork and I testify that it works. Thus I created a pull request for you to review : #41

Context (Environment)

Rpi4
Core Version: core-2021.2.3
Supervisor Version: supervisor-2021.02.11
Operating System: Home Assistant OS 5.11
Addon version : 2.4.2-dht2
EDIT : I tried the apparmor correction on both Home Assistant OS 5.11 and Home Assistant OS 5.12. It worked in both cases.

[Marnalas]

Just installed and tried the 2.4.2-dht3. It works !

Thank you very much. Have a nice day.