Deadlocks with rootless podman container

[Diniboy1123]

---

Expected Behavior

Plex should work and its database wouldn't be locked forever.

Current Behavior

I use this container on a Fedora Server 34 x64 host and I am running the container as a rootless container under the containers user via podman. The following is my run command:

/usr/bin/podman run --rm -it --name=plex --hostname=plex --dns 1.1.1.1 --network slirp4netns:port_handler=slirp4netns -p 12000:32400 -e PUID=1000 -e PGID=1000 -e VERSION=latest -v /home/containers/data/Plex:/config -v /home/containers/mounts/media:/home/plex/media --security-opt label=disable ghcr.io/linuxserver/plex

It worked fine until a recent update of Plex. Since then the container still comes up as usual, but if I run something IO intensive such as a rescan or database optimization, my Plex server becomes immediately unresponsive. Then I tried to stop the container and remove it which seemed to be successful, however it seems like that there are some leftover zombie processes in these cases:

[containers@test ~]$ ps aux | grep defunct
100999    153378  0.3  0.0      0     0 ?        Zsl  Aug28  22:45 [Plex Media Serv] <defunct>
100999    875619  0.0  0.0      0     0 ?        Zl   Aug29   0:00 [Plex Media Scan] <defunct>
100999    876449  0.0  0.0      0     0 ?        Zl   Aug29   0:00 [Plex Media Scan] <defunct>
100999    876461  0.0  0.0      0     0 ?        Zl   Aug29   0:00 [Plex Media Scan] <defunct>

These are still locking the db of Plex and therefore if I launch a new container it won't be able to make modifications and I end up having more and more defunct processes all derivating from the PID 1 parent. I couldn't find a way to kill these without rebooting the box or running telinit u.

If I run Plex on the same machine with the same configuration, but bare metal it all works well.

Any ideas what could be wrong?

Steps to Reproduce

Environment

OS: Fedora Server 34
CPU architecture: x86_64
How docker service was installed: ghcr.io

Command used to create docker container (run/create/compose/screenshot)

/usr/bin/podman run --rm -it --name=plex --hostname=plex --dns 1.1.1.1 --network slirp4netns:port_handler=slirp4netns -p 12000:32400 -e PUID=1000 -e PGID=1000 -e VERSION=latest -v /home/containers/data/Plex:/config -v /home/containers/mounts/media:/home/plex/media --security-opt label=disable ghcr.io/linuxserver/plex

Docker logs

[s6-init] making user provided files available at /var/run/s6/etc...exited 0.
[s6-init] ensuring user provided files have correct perms...exited 0.
[fix-attrs.d] applying ownership & permissions fixes...
[fix-attrs.d] done.
[cont-init.d] executing container initialization scripts...
[cont-init.d] 01-envfile: executing...
[cont-init.d] 01-envfile: exited 0.
[cont-init.d] 10-adduser: executing...

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-------------------------------------
GID/UID
-------------------------------------

User uid:    1000
User gid:    1000
-------------------------------------

[cont-init.d] 10-adduser: exited 0.
[cont-init.d] 40-chown-files: executing...
[cont-init.d] 40-chown-files: exited 0.
[cont-init.d] 45-plex-claim: executing...
[cont-init.d] 45-plex-claim: exited 0.
[cont-init.d] 50-gid-video: executing...
[cont-init.d] 50-gid-video: exited 0.
[cont-init.d] 60-plex-update: executing...
Atempting to upgrade to: 1.24.2.4973-2b1b51db9
2021-09-01 15:49:29 URL:https://downloads.plex.tv/plex-media-server-new/1.24.2.4973-2b1b51db9/debian/plexmediaserver_1.24.2.4973-2b1b51db9_amd64.deb [86646728/86646728] -> "/tmp/plexmediaserver_1.24.2.4973-2b1b51db9_amd64.deb" [1]
(Reading database ... 10541 files and directories currently installed.)
Preparing to unpack .../plexmediaserver_1.24.2.4973-2b1b51db9_amd64.deb ...
PlexMediaServer install: Pre-installation Validation.
PlexMediaServer install: Custom environment detected.  Skipping preinstallation validation.
Unpacking plexmediaserver (1.24.2.4973-2b1b51db9) over (1.24.1.4931-1a38e63c6) ...
Setting up plexmediaserver (1.24.2.4973-2b1b51db9) ...
PlexMediaServer install: Custom environment detected.  Skipping postinstallation tasks. Continuing.
[cont-init.d] 60-plex-update: exited 0.
[cont-init.d] 90-custom-folders: executing...
[cont-init.d] 90-custom-folders: exited 0.
[cont-init.d] 99-custom-scripts: executing...
[custom-init] no custom files found exiting...
[cont-init.d] 99-custom-scripts: exited 0.
[cont-init.d] done.
[services.d] starting services
[services.d] done.
Starting Plex Media Server.

[github-actions]

Thanks for opening your first issue here! Be sure to follow the bug or feature issue templates!

[aptalca]

Our images do not support rootless as the supervisor we use, s6, and our init processes require root for the container.

[Diniboy1123]

Within the container there is a root user. And it worked before. On the host its running rootless. But the container itself isn't.

As I said plex even starts and runs fine, I can even start some content right until I initiate a media rescan for example.

[aptalca]

Like I said, we can't officially support it as it's an environment not tested or supported by us, but I'd recommend checking the plex server logs in the config folder to see what's going on as the issues seem to arise during a plex action

[inittux111]

I'm not experiencing any problems with podman as a rootless container using podman, the only difference I see is you are using "--network slirp4netns:port_handler=slirp4netns" for your network option, while the documentation of docker-plex seems to require you to use "host" for the network option.

[Diniboy1123]

If you are running rootless, how come you can use host networking?

[inittux111]

If you are running rootless, how come you can use host networking?

Because when just using -p to bind the ports I wasn't able to access my plex container, so I used host instead because it was also mentioned in the docker-plex documentation.

[j0nnymoe]

If you use bridge networking with plex, you need to use the plex_claim env to get it setup initially.

[Diniboy1123]

For my slirp4netns works fine. I just thought host networking is rootfull only.

But I will close the issue as this is unsupported.

[inittux111]

If you use bridge networking with plex, you need to use the plex_claim env to get it setup initially.

I didn't know that. Thanks! How do you generate a PLEX_CLAIM token, I can't find any Plex documentation about that?

[j0nnymoe]

Link is in our readme with a brief explanation: https://docs.linuxserver.io/images/docker-plex#environment-variables-e