Run zend from a specified lower port using authbind

Set port variable
Install and configure authbind
Update firewall rule
Overwrite zend systemd unit files and reload the daemon
Replace port 9033 with new port in zen.conf
Restart zend and zentracker

NOTE: After executing the following steps for this guide, if you have a need to run zend manually, you will need to instead use the following: authbind --deep /usr/bin/zend

If you need to run zend manually or need to run a rescan or reindex, those would be accomplished as follows
- authbind --deep /usr/bin/zend
- authbind --deep /usr/bin/zend --rescan
- authbind --deep /usr/bin/zend --reindex


PORT=<port>
sudo apt-get install authbind -y
sudo ufw allow $PORT/tcp
echo \
"[Unit]
Description=Zen daemon
 
[Service]
User=$USER
Type=forking
ExecStart=/usr/bin/authbind --deep /usr/bin/zend -daemon -pid=$HOME/.zen/zend.pid
PIDFile=$HOME/.zen/zend.pid
Restart=always
RestartSec=10
 
[Install]
WantedBy=multi-user.target" | sudo tee /lib/systemd/system/zend.service
echo \
"[Unit]
Description=zenupdate.service
  
[Service]
Type=oneshot
ExecStart=/usr/bin/certbot -q renew --deploy-hook \"cat /etc/letsencrypt/live/$FQDN/chain.pem|sudo awk 'split_after==1{n++;split_after=0} /-----END CERTIFICATE-----/ {split_after=1} {print > \"/usr/local/share/ca-certificates/intermediate-cert\" n \".crt\"}' && update-ca-certificates --fresh && systemctl restart zend\"
PrivateTmp=true" | sudo tee /lib/systemd/system/zenupdate.service
echo \
"[Unit]
Description=Run zenupdate unit twice a month @ 06:00:00 (UTC)
 
[Timer]
OnCalendar=*-*-01 06:00:00
OnCalendar=*-*-03 06:00:00
Unit=zenupdate.service
Persistent=true
 
[Install]
WantedBy=timers.target" | sudo tee /lib/systemd/system/zenupdate.timer
sudo systemctl daemon-reload
sed -i "s/port=9033/port=$PORT/g" ~/.zen/zen.conf
sudo ufw delete allow 9033/tcp
sudo systemctl restart zend zentracker

	Description	Command
1	Set a port variable, replace <port> with your port number, remove <brackets>	PORT=<port>
2	Install and configure authbind using the custom port set in the previous step	sudo apt-get install authbind -y sudo touch /etc/authbind/byport/$PORT sudo chown $USER /etc/authbind/byport/$PORT chmod 755 /etc/authbind/byport/$PORT
3	Add your port to your firewall rule set	sudo ufw allow $PORT/tcp
4	Overwrite existing zend systemd unit file, copy and paste the entire block of text	echo \ "[Unit] Description=Zen daemon [Service] User=$USER Type=forking ExecStart=/usr/bin/authbind --deep /usr/bin/zend -daemon -pid=$HOME/.zen/zend.pid PIDFile=$HOME/.zen/zend.pid Restart=always RestartSec=10 [Install] WantedBy=multi-user.target" \| sudo tee /lib/systemd/system/zend.service
5	Overwrite existing zenupdate systemd unit file, copy and paste the entire block of text	echo \ "[Unit] Description=zenupdate.service [Service] Type=oneshot ExecStart=/usr/bin/certbot -q renew --deploy-hook \"cat /etc/letsencrypt/live/$FQDN/chain.pem\|sudo awk 'split_after==1{n++;split_after=0} /-----END CERTIFICATE-----/ {split_after=1} {print > \"/usr/local/share/ca-certificates/intermediate-cert\" n \".crt\"}' && update-ca-certificates --fresh && systemctl restart zend\" PrivateTmp=true" \| sudo tee /lib/systemd/system/zenupdate.service
6	Overwrite existing zenupdate timer systemd unit file, copy and paste the entire block of text	echo \ "[Unit] Description=Run zenupdate unit twice a month @ 06:00:00 (UTC) [Timer] OnCalendar=--01 06:00:00 OnCalendar=--03 06:00:00 Unit=zenupdate.service Persistent=true [Install] WantedBy=timers.target" \| sudo tee /lib/systemd/system/zenupdate.timer
7	Reload the systemd daemon to load the changes	sudo systemctl daemon-reload
8	Replace port 9033 with new port in zen.conf	sed -i "s/port=9033/port=$PORT/g" ~/.zen/zen.conf
9	Remove the old 9033 firewall rule	sudo ufw delete allow 9033/tcp
10	Restart zend and zentracker	sudo systemctl restart zend zentracker