[ale] ssh question

[Michael H. Warfield]

On Thu, 2012-05-10 at 10:18 -0400, Scott McBrien wrote:
> Use an ssh key for your authentication and then:

> ssh servername 'commands; to; run'

> The ssh session will close when your commands exit.

Not totally true.  If it's a single command and it forks a daemon into
the background which then does not close stdout and stderr (which is
what the init script he was running does) then sshd will still hang.  If
you do multiple commands and the last command does not do this, then
sshd will terminate because the file descriptors are closed.  This is a
long standing known behavior of OpenSSH.

I agree.  He seriously needs to ditch the passwords and go with
authentication keys.  On top of that, his example, assuming it was an
example, password was only 8 characters and only lower case alpha and a
number.  Really???  Maybe he was just giving a silly example, I don't
know.  IAC, he should NOT be using passwords at all but that was not the
cause of his process hanging there and not exiting.

Regards,
Mike

> -Scott
> 
> On May 10, 2012, at 7:59 AM, Edward Holcroft <eholcroft at mkainc.com> wrote:
> 
> > Morning all
> > 
> > I need to run a command on an internal server that will restart a given service, in this case asterisk, without user intervention. I using this:
> > 
> > sshpass -p '1qazxsw2' ssh -o StrictHostKeyChecking=no root at 192.168.50.87 /etc/init.d/asterisk restart
> > 
> > The problem is this command never logs out:
> > 
> > Stopping safe_asterisk: [  OK  ]
> > Shutting down asterisk: [  OK  ]
> > Starting asterisk: [  OK  ]
> > 
> > .... and there it sits, until I manually close it
> > 
> > I also tried using -t with the ssh command, which closes the session, but without restarting the service, even though it says it did:
> > 
> > $ sshpass -p '1qazxsw2' ssh -o StrictHostKeyChecking=no -t root at 192.168.50.87 "/etc/init.d/asterisk restart"
> > Stopping safe_asterisk:                                    [FAILED]
> > Shutting down asterisk:                                    [FAILED]
> > Starting asterisk:                                         [  OK  ]
> > Connection to 192.168.50.87 closed.
> > 
> > I found this article:
> > 
> > http://www.snailbook.com/faq/background-jobs.auto.html
> > 
> > And tried:
> > 
> > $ sshpass -p '1qazxsw2' ssh -o StrictHostKeyChecking=no root at 192.168.50.87 /etc/init.d/asterisk restart < /dev/null
> > 
> > which also does not close.
> > 
> > Any ideas on how I can get this to run the way I want it to?
> > 
> > ed
> > -- 
> > Edward Holcroft
> > Madsen Kneppers & Associates Inc.
> > 3020 Holcomb Bridge Rd. NW
> > Norcross, GA
> > 30071
> > Tel (770) 446-9606
> > GoogleVoice (678) 587-8649
> > 
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-- 
Michael H. Warfield (AI4NB) | (770) 985-6132 |  mhw at WittsEnd.com
   /\/\|=mhw=|\/\/          | (678) 463-0932 |  http://www.wittsend.com/mhw/
   NIC whois: MHW9          | An optimist believes we live in the best of all
 PGP Key: 0x674627FF        | possible worlds.  A pessimist is sure of it!
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