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Remotely close & rerun SSH connection


 
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# 1  
Old 08-12-2013
Remotely close & rerun SSH connection

I'm trying to remotely run an upgrade script (via SSH) that update the SSH script on several hosts, just need to add several flags for the ssh command to look like this:

Code:
ssh -Nf -i id_logs -o ExitOnForwardFailure=yes -o StrictHostKeyChecking=no -o ServerAliveInterval=60 -o ServerAliveCountMax=5 -R <port>:127.0.0.1:22 <user>@<host>

after successfully update the SSH script located on the remote hosts I want to restart the SSH process, then reconnect again to check the new connection has established successfully - my problem is that after I kill the SSH process I get kicked out of the host, and obviously can't rerun the SSH tunnel,

I was thinking of running another local script with sleep of 10seconds before killing the SSH process that will recover the SSH..but that doesn't work.
Does anyone has a good solution ? I think my idea is a bit primitive..there must be a better way to do it.

thanks !

Last edited by OdedOvdat; 08-12-2013 at 04:26 PM..
# 2  
Old 08-12-2013
Why are you killing the sshd? Why not restart it using service or init.d?
Yes, you will be kicked off, but you can connect back again after, say 10 sec, and verify the connection.

--ahamed

Last edited by ahamed101; 08-12-2013 at 04:30 PM..
# 3  
Old 08-12-2013
Either use a different protocol or wait longer. It sounds like you're not waiting long enough for the start. You could also add logic in the script that restarts the sshd daemon send mail to you. If you wanted to automate that you could send an email to a user account that had a .forward file or an alias pointing a script that could ssh back.
# 4  
Old 08-12-2013
I don't need to restart the SSH service
I just need to restart the SSH process so it will run with the latest configuration

the old SSH script looks like this:
Code:
ssh -Nf -i id_logs  -R <port>:127.0.0.1:22 <user>@<host>

and after the update script it looks like this:
Code:
ssh -Nf -i id_logs -o ExitOnForwardFailure=yes -o StrictHostKeyChecking=no -o ServerAliveInterval=60 -o ServerAliveCountMax=5 -R <port>:127.0.0.1:22 <user>@<host>

so basically I need to kill the SSH tunnel (kill <pid>)
and then run again the ssh script with the latest flags
# 5  
Old 08-13-2013
IMHO you cannot kill/restart the reverse connection without killing the whole ssh.
Do the kill from a second ssh connection!
This can already be the final ssh connection if its reverse connection port is different.
 

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