docker-plex/root/etc/s6-overlay/s6-rc.d/init-plex-claim/run

#!/usr/bin/with-contenv bash

if grep -qs "PlexOnlineToken" "/config/Library/Application Support/Plex Media Server/Preferences.xml"; then
    echo "**** Server already claimed ****"
    exit 0
elif [ -z "$PLEX_CLAIM" ]; then
    echo "**** Server is unclaimed, but no claim token has been set ****"
    exit 0
fi
PREFNAME="/config/Library/Application Support/Plex Media Server/Preferences.xml"
if [ ! -f "${PREFNAME}" ]; then
    UMASK_SET="${UMASK_SET:-022}"
    umask "$UMASK_SET"
    echo "Temporarily starting Plex Media Server."
    export PLEX_MEDIA_SERVER_INFO_MODEL=$(uname -m)
    export PLEX_MEDIA_SERVER_INFO_PLATFORM_VERSION=$(uname -r)
    s6-setuidgid abc /bin/bash -c \
        'LD_LIBRARY_PATH=/usr/lib/plexmediaserver:/usr/lib/plexmediaserver/lib /usr/lib/plexmediaserver/Plex\ Media\ Server' & PID=$!
    echo "Waiting for Plex to generate its config"
    DBNAME="/config/Library/Application Support/Plex Media Server/Plug-in Support/Databases/com.plexapp.plugins.library.db-wal"
    until [ -f "${DBNAME}" ]; do
        sleep 1
    done
    while true; do
        echo "Waiting for database creation to complete..."
        if [ -z "${COMPARE_MD5+x}" ]; then
            COMPARE_MD5=$(md5sum "${DBNAME}"| cut -c1-8)
            sleep 3
        else
            sleep 3
            CURRENT_MD5=$(md5sum "${DBNAME}"| cut -c1-8)
            if [ "${CURRENT_MD5}" == "${COMPARE_MD5}" ]; then
                break
            else
                COMPARE_MD5=$(md5sum "${DBNAME}"| cut -c1-8)
            fi
        fi
    done
    until grep -qs "ProcessedMachineIdentifier" "${PREFNAME}"; do
        sleep 1
    done
    while true; do
        echo "Waiting for pref file creation to complete..."
        if [ -z "${PREF_COMPARE_MD5+x}" ]; then
            PREF_COMPARE_MD5=$(md5sum "${PREFNAME}"| cut -c1-8)
            sleep 3
        else
            sleep 3
            PREF_CURRENT_MD5=$(md5sum "${PREFNAME}"| cut -c1-8)
            if [ "${PREF_CURRENT_MD5}" == "${PREF_COMPARE_MD5}" ]; then
                break
            else
                PREF_COMPARE_MD5=$(md5sum "${PREFNAME}"| cut -c1-8)
            fi
        fi
    done
    echo "Stopping Plex to claim server"
    while ps -p $PID > /dev/null; do
        kill $PID
        sleep 1
    done
    echo "Plex stopped"
fi

ProcessedMachineIdentifier=$(sed -n "s/^.*ProcessedMachineIdentifier=\"\([^\"]*\)\".*$/\1/p" "${PREFNAME}")
PlexOnlineToken="$(curl -X POST \
    -H 'X-Plex-Client-Identifier: '"${ProcessedMachineIdentifier}" \
    -H 'X-Plex-Product: Plex Media Server'\
    -H 'X-Plex-Version: 1.1' \
    -H 'X-Plex-Provides: server' \
    -H 'X-Plex-Platform: Linux' \
    -H 'X-Plex-Platform-Version: 1.0' \
    -H 'X-Plex-Device-Name: PlexMediaServer' \
    -H 'X-Plex-Device: Linux' \
    "https://plex.tv/api/claim/exchange?token=${PLEX_CLAIM}" \
    | sed -n 's/.*<authentication-token>\(.*\)<\/authentication-token>.*/\1/p')"

if [ -n "$PlexOnlineToken" ]; then
    echo "Server claimed successfully, navigate to http://serverip:32400/web to complete plex setup."
    sed -i "s/\/>/ PlexOnlineToken=\"${PlexOnlineToken}\"\/>/g" "${PREFNAME}"
else
    echo "Unable to claim Plex server. Either manually claim by connecting to http://serverip:32400/web from the same network subnet, or recreate container with a new claim token."
fi