[smokeping-users] ssh-keyscan error starting from boot only

[Jim Long]

On Tue, Feb 05, 2013 at 02:47:17AM +0000, Vinny_Abello at Dell.com wrote:
> Thanks for the tip. On my system I actually found that
> smokeping is starting before, sshd oddly enough.

Not all that odd....

In 2008, the FreeBSD port's startup script was changed from rev.
1.1 to 1.2, and one of the changes was to add a dependency on the
sshd service:

http://www.freebsd.org/cgi/cvsweb.cgi/ports/net-mgmt/smokeping/files/smokeping.in.diff?r1=text&tr1=1.1&r2=text&tr2=1.2

I run an older smokeping, and have version 1.5 of the startup
script, so I was still seeing the ssh dependency on my system.

Last June, the ssh dependency was removed in version 1.7 of the script:

http://www.freebsd.org/cgi/cvsweb.cgi/ports/net-mgmt/smokeping/files/smokeping.in.diff?r1=text&tr1=1.6&r2=text&tr2=1.7

So for those who have installed a recent version of the smokeping
port, the behaviour you're seeing is very explainable.  I don't
know the underlying reasons for why the change was made, however.
Perhaps Rodrigo knows.

Jim


> I modified the smokeping rc file from:
> 
> # REQUIRE: LOGIN
> 
> to
> 
> # REQUIRE: LOGIN sshd
> 
> The order now looks correct and rcorder shows smokeping will be started after sshd now. I think that dependency should probably be in place in the FreeBSD port rc script by default, unless there is a more proper way to do this. Perhaps something else is wrong on my system and LOGIN is expected to be dependend on sshd or some other chain of events.
> 
> -Vinny
> 
> -----Original Message-----
> From: Jim Long [mailto:smokeping at museum.rain.com] 
> Sent: Wednesday, January 23, 2013 4:12 PM
> To: Abello, Vinny
> Cc: smokeping-users at lists.oetiker.ch
> Subject: Re: [smokeping-users] ssh-keyscan error starting from boot only
> 
> On Wed, Jan 23, 2013 at 07:17:09PM +0000, Vinny_Abello at Dell.com wrote:
> > Hello,
> > 
> > I'm wondering if anyone has encountered this problem. We're running smokeping 2.6.7 on FreeBSD 8.3. When the system boots up, the startup script tries to start smokeping, but smokeping errors out on initializing the ssh-keyscan probe with the following error:
> > 
> > Starting smokeping.
> > ### parsing dig output...OK
> > ERROR: output of '/usr/bin/ssh-keyscan -t dsa,rsa,rsa1 127.0.0.1' does not match (?i-xsm:^# \\S+ SSH-)
> > at (eval 56) line 1
> > 
> > /etc/rc: WARNING: failed to start smokeping
> > 
> > 
> > The very strange thing is if I start smokeping using the same startup script manually after the system has booted, I get no error at all and everything works fine.
> > 
> > Any thoughts on why this is and how I would go about correcting it?
> > 
> > Thanks!
> > 
> > -Vinny
> 
> Peter's assessment of the cause is probably accurate, but the
> FreeBSD rc(8) system likely is already ordering your startup
> scripts correctly.  
> 
> Read: http://www.freebsd.org/doc/handbook/configtuning-rcd.html
> 
> And look at your system's current service dependency order:
> 
> rcorder /etc/rc.d/* /usr/local/etc/rc.d/* | less
> 
> On my system, I see that sshd starts immediately before
> smokeping.  If sshd forks into the background quickly, before the
> service is 100% up and running, smokeping could start before sshd
> is ready for it.
> 
> I suspect you'll have to put a 'sleep 3' or something at the
> top of your smokeping startup script, for some value of '3'.
> 
> Jim