garbage script cobbled together to setup a terraria server and provide systemd unit file

setup-terraria.sh

#!/bin/bash

# note: RUNNING THIS SCRIPT COULD DESTROY EXTANT SERVERS THAT ARE SAME VERSION

# stop script on first error
set -e

# sudo check
if [ "$(id -u)" -ne 0 ]
then
  echo "You must be root to run this script; try again with sudo" >&2
  exit 1
fi

# if they didnt pass the version in as first argument, prompt for it
if [ -n "$1" ]
then
  terraria_version="$1"
else
  read -rp "What version of Terraria to install? " terraria_version
fi

# create user to own terraria server process(s)
echo "Creating system account to run terraria server..."
useradd -r terraria 2>/dev/null || echo "User 'terraria' already exists, not creating again"
usermod -d /etc/terraria terraria 2>/dev/null
addgroup terraria-ops 2>/dev/null || echo "Group 'terraria-ops' already exists, not creating again"
usermod -a -G terraria-ops terraria 2>/dev/null

# create generic base directory for all server versions
if [ ! -e /etc/terraria ]
then
  echo "Creating server directory in /etc/terraria..."
  mkdir /etc/terraria
else
  echo "Server directory in /etc/terraria already exists, skipping creation..."
fi

# move into terraria dir and do all further work there
cd /etc/terraria

# make worlds dir if not exists
if [ ! -d worlds ]
then
  echo "Creating worlds directory in /etc/terraria/worlds..."
  mkdir worlds
  chmod 775 worlds
else
  echo "Worlds directory already exists in /etc/terraria/worlds; skipping creation"
fi

# find the server archive
echo "Locating server download URL..."
collapsed_ver="$(echo "$terraria_version" | sed -e 's/\.//g')"
server_archive_name="terraria-server-${collapsed_ver}.zip"

# this horrible kludge is because terraria doesn't really have a cdn with
# well-formed and consistent URLs; that's fine, we'll just download the page of the
# wiki which has them all and crawl it to find the right URL, since the archive name
# IS well-formed we can look for that.
curl -L 'https://terraria.fandom.com/wiki/Server#Downloads' > wiki.html
server_url="$(grep "$server_archive_name" wiki.html | sed -e 's/^.*href="\(.*$\)/\1/' | sed -e 's/\(^.*\)">.*$/\1/')"
rm wiki.html
echo "Server archive is located at $server_url"

# download and extract server archive
echo "Downloading server..."
curl -LO "$server_url"
echo "Extracting server..."
unzip "$server_archive_name"
rm "$server_archive_name"

echo "Setting up server..."
cd "${collapsed_ver}"
# erase non-linux versions
rm -r Mac Windows
cd Linux
# set permissions
chmod 760 "TerrariaServer"*

read -srp "What should the server password be? " server_pass


# create config, note that the use of relative paths here
# makes it so server needs to run from the particular working dir
mkdir conf
cat <<- EOF > "conf/terraria.cfg"
	################################
	# Game settings. Set as needed #
	################################
	
	# message of the day
	motd=We own fucking *helicopters* bitch!
	
	# maximum number of players allowed in server
	maxplayers=8
	
	# anti-cheat protection
	secure=1
	
	# server password
	password=$server_pass
	
	# server language
	language=en/US
	
	# set this if you have a world you want to autostart with.
	# you MUST connect to the console to setup your world
	# first or import an existing one
	# world=/etc/terraria/worlds/world-file.wld
	
	
	################################################
	# Path settings. Set to where these files are. #
	################################################
	
	# where the worlds are saved to and loaded from
	worldpath=/etc/terraria/worlds
	
	# location of banlist
	banlist=conf/banlist.txt
	
	
	#########################################
	# network settings, not usually changed #
	#########################################
	
	# listening port
	port=7777
	
	# disable automatic port-forwarding
	upnp=0
	
	# set how often npc updates are sent, presumably per second.
	# less is less 'skipping around' but more bandwidth. Lower if
	# enemies are skipping around, raise if you are using too much
	# bandwidth
	npcstream=60
	
EOF

chown terraria:terraria /etc/terraria
chown -R terraria:terraria-ops /etc/terraria/*
chmod -R 770 /etc/terraria/$collapsed_ver/Linux/conf

# setup the socket
mkdir /var/terraria
chgrp terraria-ops /var/terraria
chmod g+ws /var/terraria
sudo -u terraria HOME=/etc/terraria -s tmux -S /var/terraria/sock


terraria_version=1.4.2.3
collapsed_ver=1423
# oh my god this is a mess this should NOT be in a bash script jfc deka
# and yet here it is. honk.
echo "[Unit]" > ~/terraria.service
echo "Description=Terraria v$terraria_version" >> ~/terraria.service
cat <<- 'EOF' >> ~/terraria.service
	
	[Service]
	User=terraria
	Type=forking
EOF
echo WorkingDirectory=/etc/terraria/$collapsed_ver/Linux >> ~/terraria.service
cat <<- 'EOF' >> ~/terraria.service
	ExecStartPre=/bin/bash -c "tmux -S /var/terraria/sock send-keys -t terraria 'exit' enter >/dev/null 2>&1 || echo 'No console needs closing'"
	ExecStart=/bin/bash -c "sleep 1 && tmux -S /var/terraria/sock new-session -s terraria -d"
	ExecStartPost=/bin/bash -c "sleep 3"
	ExecStartPost=/bin/bash -c "tmux -S /var/terraria/sock send-keys -t terraria './TerrariaServer -config conf/terraria.cfg ; exit $?' enter"
	ExecStop=/bin/bash -c "tmux -S /var/terraria/sock send-keys -t terraria 'exit' enter"
	ExecStop=/bin/bash -c "sleep 10"
	
	[Install]
	WantedBy=multi-user.target
EOF

mv ~/terraria.service /etc/systemd/system
systemctl daemon-reload
systemctl start terraria || systemctl status terraria

oh my god do not run this as a script you will regret it

this is so so broken atm. each step can be looked at tho ig. glub.