tldr/pages/common/autossh.md

autossh

Run, monitor and restart SSH connections. Auto-reconnects to keep port forwarding tunnels up. Accepts all SSH flags. More information: https://www.harding.motd.ca/autossh.

• Start an SSH session, restarting when the [M]onitoring port fails to return data:

autossh -M {{monitor_port}} "{{ssh_command}}"

• Forward a [L]ocal port to a remote one, restarting when necessary:

autossh -M {{monitor_port}} -L {{local_port}}:localhost:{{remote_port}} {{user}}@{{host}}

• Fork autossh into the background before executing SSH and do [N]ot open a remote shell:

autossh -f -M {{monitor_port}} -N "{{ssh_command}}"

• Run in the background, with no monitoring port, and instead send SSH keep-alive packets every 10 seconds to detect failure:

autossh -f -M 0 -N -o "ServerAliveInterval 10" -o "ServerAliveCountMax 3" "{{ssh_command}}"

• Run in the background, with no monitoring port and no remote shell, exiting if the port forward fails:

autossh -f -M 0 -N -o "ServerAliveInterval 10" -o "ServerAliveCountMax 3" -o ExitOnForwardFailure=yes -L {{local_port}}:localhost:{{remote_port}} {{user}}@{{host}}

• Run in the background, logging autossh debug output and SSH verbose output to files:

AUTOSSH_DEBUG=1 AUTOSSH_LOGFILE={{path/to/autossh_log_file.log}} autossh -f -M {{monitor_port}} -v -E {{path/to/ssh_log_file.log}} {{ssh_command}}