Add magnet files from watch dir to transmission (with authentication, for linuxserver.io docker image)

grab-magnets-from-watchdir.custom-cont-init-script

#!/bin/bash
# Filename: grab-magnets-from-watchdir.custom-cont-init-script 
# Save this file in /config/custom-cont-init.d/
# This way it will run everytime the container is created and will add the crontab entry and transmission authentication

# Save env files to get authentication
printenv | sed 's/^\(.*\)$/export \1/g' > /root/container.env
# Add entry to crontab, runs every minute
echo '* * * * * . /root/container.env; /config/grab-magnets-from-watchdir.sh' >> /etc/crontabs/root

grab-magnets-from-watchdir.sh

#!/usr/bin/env bash
# Filename: grab-magnets-from-watchdir.sh
# Save this file into your /config directory

tr=$(which transmission-remote) # set path for transmission-remote binary

if [ -f /watch/*.magnet ]
then
  for t in /watch/*.magnet; do
    echo "Adding "$t""
    m=$(cat "$t") # get contents of magnet file
    $tr -n "$USER:$PASS" --add $m && \
    /bin/mv "$t" "$t".added # add to transmission and rename the magnet file
  done
fi