Autossh using systemd

README-autossh-systemd.txt

1) ==== Autossh using systemd ====

Example from

https://gist.github.com/drmalex07/c0f9304deea566842490

2) =============

Install autossh

3) ==== /etc/default/secure-tunnel@yourjumpsshserver == change yourjumpsshserver to your ip or dnsname

TARGET=yourjumpsshserver
LOCAL_ADDR=0.0.0.0
LOCAL_PORT=22
# port that will be use to ssh at remote server
REMOTE_PORT=54322
# change user as per remote server
USERNAME=user
# change SSH port used at jump server
SSH_TARGET_PORT=22


4) ==== /etc/systemd/system/[email protected]

[Unit]
Description=Setup a secure tunnel to %I
After=network.target

[Service]
Environment="LOCAL_ADDR=localhost"
EnvironmentFile=/etc/default/secure-tunnel@%i
###ExecStart=/usr/bin/ssh -NT -o ServerAliveInterval=60 -o ExitOnForwardFailure=yes -L ${LOCAL_ADDR}:${LOCAL_PORT}:localhost:${REMOTE_PORT} ${USERNAME}@${TARGET}
Environment="AUTOSSH_GATETIME=0"
ExecStart=/usr/bin/autossh -M 0 -o "ExitOnForwardFailure=yes" -o "ServerAliveInterval 30" -o "ServerAliveCountMax 3" -NR ${REMOTE_PORT}:${LOCAL_ADDR}:${LOCAL_PORT} -p ${SSH_TARGET_PORT} ${USERNAME}@${TARGET}

# Restart every >2 seconds to avoid StartLimitInterval failure
RestartSec=5
Restart=always

[Install]
WantedBy=multi-user.target

6) ===== SSH key copy to yourjumpsshserver

As root (systemd running as root)

ssh-copy-id user@yourjumpsshserver -p 443

You may need to run ssh-keygen. Make sure ls /root/.ssh is empty

5) ============ systemctl

systemctl daemon-reload
systemctl status secure-tunnel@yourjumpsshserver
systemctl enable secure-tunnel@yourjumpsshserver
systemctl start secure-tunnel@yourjumpsshserver
systemctl stop secure-tunnel@yourjumpsshserver

==== Autossh using systemd ====