ssh tunnel with auto reconnect ability

while [ ! -f /tmp/stop ]; do ssh -o ExitOnForwardFailure=yes -R 2222:localhost:22 target "while nc -zv localhost 2222; do sleep 5; done"; sleep 5;done

13
By: jianingy
2009-02-08 12:45:43

What Others Think

check out the -N option to ssh Do not execute a remote command. This is useful for just forwarding ports (protocol version 2 only).
devnull · 506 weeks ago
You might want to use ~/stop or ~/.stop as the file to stop your loop, since it's usually possible for anyone on the system to reach /tmp (doesn't matter on a single-user box, but it's generally a good idea to stay in your home directory anyway).
mulad · 504 weeks and 5 days ago
Or just run the who shebang out of /etc/inittab with the "respawn" option. See http://www.deer-run.com/~hal/sysadmin/SSH-SyslogNG.html
Hal_Pomeranz · 478 weeks and 1 day ago
Dunno about this "target" piece in your command. I assume your command is meant to provide a way to keep trying to connect if it fail. Inspired of this, I wrote my own command that help me automatically reconnect immediately after the connecting pipe is broken: while true; do if ! nc -z localhost 7070 > /dev/null; then ssh -N -D 127.0.0.1:7070 -p 22 someone@somesite.com; else echo 'not connected, retry after 10 seconds...'; fi; sleep 10; done
fwonce · 281 weeks and 3 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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