Yet another WORKING autossh systemd script

sshtunnel.service

[Unit]
Description=Keeps a tunnel to 'remote.com' open
After=network.target network-online.target sshd.service
#####################
#Reference: https://transang.me/create-a-remote-ssh-background-service-with-autossh-and-systemctl/

[Service]
User=YOUR_USER_NAME
Environment="AUTOSSH_GATETIME=30"
Environment="AUTOSSH_POLL=30"
Environment="AUTOSSH_FIRST_POLL=30"

Type=forking

RuntimeDirectory=sshtunnel
RuntimeDirectoryMode=0750
Environment="AUTOSSH_PIDFILE=/var/run/sshtunnel/sshtunnel.pid"
PIDFile=/var/run/sshtunnel/sshtunnel.pid

# Set aggressive network timeouts not autossh systemd unit timeouts and also avoid Broken pipe errors.
# After 30 seconds of no server response, Autossh will re-negotiate a new session.
# This assumes SSH version >=2. See https://bit.ly/3bINv8v
# Set 'ClientAliveInterval 10' in the remote sshd_config so unresponsive SSH clients will be
# disconnected after approx. (10 x ClientAliveCountMax) = 30 seconds
# -p [PORT]
# -l [user]
# -M 0 --> no monitoring, no need to supply since autossh script will determine an available port
# -N Just open the connection and do nothing (not interactive)
# LOCALPORT:IP_ON_EXAMPLE_COM:PORT_ON_EXAMPLE_COM
ExecStart=/usr/bin/autossh -CNfg -q \
-o "ServerAliveInterval 10" \
-o "ServerAliveCountMax 3" \
-o "StreamLocalBindUnlink yes" \
-o "ExitOnForwardFailure yes" \
-l YOUR_USER_NAME -R YOUR_REDIRECTION_PORT:localhost:22 remote.com

ExecReload=kill -HUP $MAINPID

ExecStop=/bin/kill $MAINPID
Restart=always
# On Linux TCP_TIMEWAIT_LEN is not tunable and set to (60*HZ), about 60 seconds. TCP_FIN_TIMEOUT also defauls to 60 seconds.
RestartSec=60
# See systemd.kill(5)
KillMode=process

[Install]
WantedBy=multi-user.target

This systemd service file can manage your autossh session very well (start/stop/restart).
Here are the steps to install/start:

cp /path/to/sshtunnel.service /etc/systemd/system/
systemctl daemon-reload
systemctl enable sshtunnel.service
systemctl start sshtunnel.service

When this service is started, systemd will put autossh's pid into /var/run/sshtunnel/sshtunnel.pid

Steps to uninstall:

systemctl stop sshtunnel.service
systemctl disable sshtunnel.service
systemctl daemon-reload
rm /etc/systemd/system/sshtunnel.service

Q: Since we can setup ssh redirection systemd service directly using similar way, Is autossh redundant?
A: I don't think so, autossh can monitor the health of the ssh connection and reconnect if needed.

P.S. this systemd script works in Debian, may need to adapt accordingly for other systems.