Programmatically modify essential preferences on start

[egladman]

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• I have read the contributing guideline and understand that I have made the correct modifications

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Description:

Optionally programmatically patch Library/Application Support/Plex Media Server/Preferences.xml on start

Benefits of this PR and context:

This simplifies/automates setup for the following scenarios:

• Running plex behind a reverse proxy with a custom tld or nonstandard port
• Running plex with the bridge network driver (the default). Plex will treat local network traffic as remote, unless "LAN Networks" under network settings in the web GUI is set.
  • I'm against running containers with host networking, I prefer to only publish 32400

Yes all of these settings can be configured via the web GUI, but I consider this a clunky solution. I'm striving for zero human intervention.

I'd be happy to elaborate on my use case, just let me know.

How Has This Been Tested?

I'm over simplifying things with the following one-liner, but it demonstrates how it works

❯ docker run -it --env SERVER_NAME="foobar" $(docker build . --no-cache --quiet) /bin/bash -c "sleep 60 && cat /config/Library/Application\ Support/Plex\ Media\ Server/Preferences.xml"
[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] 01-migrations: executing... 
[migrations] started
[migrations] no migrations found
[cont-init.d] 01-migrations: exited 0.
[cont-init.d] 10-adduser: executing... 
usermod: no changes

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GID/UID
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User uid:    911
User gid:    911
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[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... 



#######################################################
# Update routine will not run because you havent set  #
# the VERSION variable or you opted out of updates.   #
#          For more information checkout :-           #
#    https://github.com/linuxserver/docker-plex       #
#######################################################


[cont-init.d] 60-plex-update: exited 0.
[cont-init.d] 70-plex-modify-preferences: executing... 
[cont-init.d] 70-plex-modify-preferences: 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.
Critical: libusb_init failed
<?xml version="1.0" encoding="utf-8"?>
<Preferences FriendlyName="foobar" OldestPreviousVersion="1.25.1.5286-34f965be8" MachineIdentifier="XXXXXXXXXXXXXXXXXXXXXXXX" ProcessedMachineIdentifier="XXXXXXXXXXXXXXXXXXXXXXXX" AnonymousMachineIdentifier="XXXXXXXXXXXXXXXXXXXXXXXX" MetricsEpoch="1"/>
[cmd] /bin/bash exited 0
[cont-finish.d] executing container finish scripts...
[cont-finish.d] done.
[s6-finish] waiting for services.
[s6-finish] sending all processes the TERM signal.
[s6-finish] sending all processes the KILL signal and exiting.

Source / References:

• Provide a way to name a new PMS programmatically through environment variable  #283

[github-actions]

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[LinuxServer-CI]

I am a bot, here are the test results for this PR:
https://ci-tests.linuxserver.io/lspipepr/plex/1.25.1.5286-34f965be8-pkg-2fddb981-pr-293/index.html
https://ci-tests.linuxserver.io/lspipepr/plex/1.25.1.5286-34f965be8-pkg-2fddb981-pr-293/shellcheck-result.xml

[aptalca]

Thanks for the PR, but we don't like to directly modify plex's preferences.xml because we don't control the upstream and if they make any changes, we won't even know until after something breaks.

Plus, as you said, these are all configurable via the gui. We try to create env vars for things that are necessary to get the gui up and accessible, and the rest can be done via the gui.

While I understand some people prefer to have these set up in docker arguments, I think it's much better if it's a mod, rather than built into our image: https://mods.linuxserver.io/?mod=create

[egladman]

That's disappointing, but I understanding not wanting to make changes to the xml. I'll probably end up maintaining my own fork, as I think this is a problem worth solving. Thanks for the quick response.

[aptalca]

You don't need to maintain a fork if you submit a mod like I linked to above