Per user transmission-daemon on Debian with systemd

transmission-per-user.bash

#!/bin/bash

sudo apt-get install transmission-daemon

service_path=/lib/systemd/system/[email protected]

if ! [ -s "$service_path" ]
  then
    sudo tee "$service_path" <<-UNIT
	[Unit]
	Description=Transmission BitTorrent Daemon for %I
	After=network.target
	
	[Service]
	User=%i
	Type=notify
	ExecStart=/usr/bin/transmission-daemon -f --log-error
	ExecReload=/bin/kill -s HUP $MAINPID
	
	[Install]
	WantedBy=multi-user.target
	UNIT

  if ! [ -s /etc/sysctl.d/20-transmission.conf ]
  then
    sudo tee /etc/sysctl.d/20-transmission.conf <<-SYSCTL
	net.core.wmem_max = 1048576
	net.core.rmem_max = 4194304
	SYSCTL
  fi
else
  printf >&2 'The unit file "%s" already exists.\n' "$service_path"
fi

cat >&2 <<-README
	To activate a transmission for a particular user, enter the following commands:
	
	    sudo systemctl enable transmission-daemon@<user>.service
	    sudo systemctl start  transmission-daemon@<user>.service
	
	If you want to deactivate the default instance, enter these commands:
	
	   sudo systemctl stop transmission-daemon.service
	   sudo systemctl disable transmission-daemon.service
	README