Rsync ssh script execution fails under cron?

[Jeff Hill]

After that warm response, I decided to try for another day to get a script 
working, to no avail.

Yes, a blank line and a "set -x" might be required (but certainly not 
always required for all cron scripts). It made no difference here, so far. 
As for the commands you didn't recognize (log_user, spawn, expect, send), 
they were part of the "expect" program the script executed, something that 
I thought was fairly common.

My intent was to avoid the security issues of logging into a remote server 
as root without a password or passphrase. At this stage, I'm willing to 
fall back to trying ssh keys without a passphrase. Again, easy enough to 
implement and launch from a script directly, but it isn't going anywhere 
under cron.

#! /bin/sh
#
/usr/bin/rsync -anrultvPz --delete -e 
/usr/bin/ssh  root at apache:"/home/jhill/" "/usr/local/bkup/home/jhill"

Setting up the keys with a blank passphrase, the above works from the 
command line and requests neither password nor passphrase. But it still 
doesn't work from cron. I've tried variations using ssh-add and/or 
ssh-agent. I've tried running it under the Debian "crontab" that allows for 
setting the user and under the standard vixie cron.  I've tried running it 
as a straight command from cron, and of course as a bash script.

I'm using rsync 2.5.6cvs, Open_SSH 3.0.2p1 on Debian sid and woody servers, 
and I'm using RSA keys. I've looked at dozens of rsa-ssh scripts, but most 
of them are pushing data to a remote and I need to pull it down from the 
server. I've read how rsync encountered freezes with OpenSSH, in the past, 
but that appears to be resolved now.

  From what I've now read, it seems like I need both ssh-add and ssh-agent. 
I've created a script for cron to call and execute ssh-agent which then 
calls another script to execute ssh-add and rsync:

----------------------
rsync1:
#! /bin/sh
#
/usr/bin/ssh-agent /bin/bash /etc/rsync2

----------------------
rsync2:
#! /bin/sh
#
/usr/bin/ssh-add /root/.ssh/id_rsa
/usr/bin/rsync -anrultvPz --delete -e "/usr/bin/ssh  -A" 
root at apache:"/home/jhill/" "/usr/local/bkup/home/jhill"
----------------------

Of course, once again, it works fine from the command line but fails when I 
try it in the crontab.

At 12:03 AM 24/06/2002 +0200, Peter T. Breuer wrote:
>"A month of sundays ago Jeff Hill wrote:"
>(in immensely long lines that I have cut to 72 chars)

I didn't wrap lines to avoid problems in understanding the line breaks in 
the script.

So . . ., I'd still appreciate some assistance, but if you're just going to 
'bash' me ;), I can do without it.

Regards,

Jeff


> > I'm no expert, but I've written a few scripts for cron before without
>
>You don't have an empty line at the end. You don't have a "set -x".
>These mark you out as definitely not an expert. There is no need
>to guess .. just do these two things and you will have all the info you
>need.
>
> > any problem.  I appreciate that this could be considered an issue with
> > cron and not rsync, but I thought users of rsync would probably have
> > experience writing such cron scripts.
>
>Well, you know that the PATH is not the same as yours in cron, yes?
>So you should START by setting the PATH  in the script.
>
> > #!/bin/sh
> > # \
> > exec expect "$0" ${1+"$@"}
>
>Error. That's an exec. We never get beyond there. And surely tehre's no
>attached console at this point, so how can it possibly work? What's
>this for? Did you mean to comment it out?
>
> > # -n dry run // --progress -v  for testing
> > # -z for file compression
> > log_user 0
>
>log_user is nothing I've ever heard of! What?
>
> > spawn time /usr/bin/rsync -anrultvPz --delete --exclude="vu/" -e 
> /usr/bin/ssh  --timeout 30 root at apache:/home/jhill/ /usr/local/bkup/home/jhill
>
>spawn? spawn? What? What's that? Are you trying to launch this in
>background? Then you want a "&". There's nothing to detach from, so
>don't waorry about it!
>
>In any case, you want to set up ssh to let you log in as root without a
>passwd. That's all.
>
>
>
> > expect "password: "
> > send "secret\n"
>
>Eh? This can't possibly do anything. This is part of a script that you
>think is taklking to something, and it is not.
>
>
>
> > log_user 1
> > interact
>
>Eh?
>
>
>It looks incredibly confused. I think you are thinking of launching
>something in the background while you deal with passwd stuff in the
>foreground. That is completely mistaken. It makes no sense.
>
>
>Set ssh to permit login without passwd for this user. That's all. It
>only needs RSA authenticatuon to be sufficient, and to have each
>others kerys in authorized_keys in .ssh both sides (well, one side,
>but you may as well have both).
>
>
>Peter