RE: Re: using expect to log into devices
Jimmy Hess > > On Tue, Jul 24, 2018 at 9:55 PM, Scott Weeks > wrote: > > > > --- valdis.kletni...@vt.edu wrote: > > From: valdis.kletni...@vt.edu > > > > On Sun, 22 Jul 2018 00:43:35 +0200, Niels Bakker said: > > > Fine as a personal exercise, of course. The inability to download > > > modules seems sadistic to me, though. > > > > Yeah... just download RANCID and check the command line options. > Expect is mainly of historical interest, and the code already exists in > several forms, so no need to completely re-invent the wheel (as a square) > here. In a follow up he stated that wasn't allowed either. > I call shenanigans about the avoidance of Perl modules.No real-world > system > has such constraints. As someone who administers systems with such constraints, allow me to say that you are incorrect in your assertion. > Besides, Expect itself is a module / extension of the Tcl language and > requires the > use of dynamically-loaded extension libraries for pattern matching and > various functions, > so using Expect would break the "No modules rule". "No PERL modules" != "no dynamically linked binaries" Jamie
Re: using expect to log into devices
On Tue, Jul 24, 2018 at 9:55 PM, Scott Weeks wrote: > > --- valdis.kletni...@vt.edu wrote: > From: valdis.kletni...@vt.edu > > On Sun, 22 Jul 2018 00:43:35 +0200, Niels Bakker said: > > Fine as a personal exercise, of course. The inability to download > > modules seems sadistic to me, though. > Yeah... just download RANCID and check the command line options. Expect is mainly of historical interest, and the code already exists in several forms, so no need to completely re-invent the wheel (as a square) here. I call shenanigans about the avoidance of Perl modules.No real-world system has such constraints. Besides, Expect itself is a module / extension of the Tcl language and requires the use of dynamically-loaded extension libraries for pattern matching and various functions, so using Expect would break the "No modules rule". If you're not allowed the use of modules, then your implementation option is pretty much to write in something that compiles to straight machine language. -- -JH
Re: using expect to log into devices
--- valdis.kletni...@vt.edu wrote: From: valdis.kletni...@vt.edu On Sun, 22 Jul 2018 00:43:35 +0200, Niels Bakker said: > Fine as a personal exercise, of course. The inability to download > modules seems sadistic to me, though. And given the adage "Never create a rule you can't enforce", I wonder how they enforce it - have to be pretty hardcore to make sure that stuff doesn't get imported via USB or tethering off a cellphone. (Or more correctly, I know how they do those sort of things if you're a spook agency or doing classified research - how do you make it palatable to employees in corporate sites?) - It's not corporate and believe me, they enforce it... ;-) scott
Re: using expect to log into devices
Was out. Late reply... --- niels=na...@bakker.net wrote: From: Niels Bakker * sur...@mauigateway.com (Scott Weeks) [Sat 21 Jul 2018, 22:38 CEST]: >I had already done this in PERL, but, even though we have PERL, we >are not allowed to download modules here. So, I'm redoing it in >Expect. I thought someone would say a "oh just and >you're done" type of response. Well, what you're doing right here is reimplementing rancid. Which is wholly unnecessary because we already have rancid, and a more modern alternative named oxidized. And you've gotten that response already. Fine as a personal exercise, of course. The inability to download modules seems sadistic to me, though. -- It IS sadistic and I don't have a choice. Can't use rancid, either. Thus my comment of $next-job and personal exercise in prep for that. But, while I'm here I want something non-GUI I can use without losing my mind. scott
Re: using expect to log into devices
On Sun, 22 Jul 2018 00:10:06 -0400, J Crowe said: > Have you looked into utilizing Ansible? Yes, we use Ansible heavily on production services. But Ansible doesn't *stop* somebody from downloading modules, especially if it's a laptop used for diagnosis/testing. pgpCUNzXhlEPO.pgp Description: PGP signature
Re: using expect to log into devices
Have you looked into utilizing Ansible? On Sat, Jul 21, 2018 at 8:22 PM wrote: > On Sun, 22 Jul 2018 00:43:35 +0200, Niels Bakker said: > > Fine as a personal exercise, of course. The inability to download > > modules seems sadistic to me, though. > > And given the adage "Never create a rule you can't enforce", I > wonder how they enforce it - have to be pretty hardcore to make > sure that stuff doesn't get imported via USB or tethering off a > cellphone. (Or more correctly, I know how they do those sort of > things if you're a spook agency or doing classified research - how > do you make it palatable to employees in corporate sites?) >
Re: using expect to log into devices
On Sun, 22 Jul 2018 00:43:35 +0200, Niels Bakker said: > Fine as a personal exercise, of course. The inability to download > modules seems sadistic to me, though. And given the adage "Never create a rule you can't enforce", I wonder how they enforce it - have to be pretty hardcore to make sure that stuff doesn't get imported via USB or tethering off a cellphone. (Or more correctly, I know how they do those sort of things if you're a spook agency or doing classified research - how do you make it palatable to employees in corporate sites?) pgpVpVUpj7aEG.pgp Description: PGP signature
Re: using expect to log into devices
* sur...@mauigateway.com (Scott Weeks) [Sat 21 Jul 2018, 22:38 CEST]: I had already done this in PERL, but, even though we have PERL, we are not allowed to download modules here. So, I'm redoing it in Expect. I thought someone would say a "oh just and you're done" type of response. Well, what you're doing right here is reimplementing rancid. Which is wholly unnecessary because we already have rancid, and a more modern alternative named oxidized. And you've gotten that response already. Fine as a personal exercise, of course. The inability to download modules seems sadistic to me, though. -- Niels.
Re: using expect to log into devices
--- ler...@gmail.com wrote:
From: Lee
> I have a file with 1000s of devices and another file
> with a list of commands. The program issues all
> commands for a device and then moves on to the next
> one using nested loops. In the debug I see the
> "spawn_id expNN" (where NN is a number that, I
> believe is representative of the number of file
> descriptors used in the system) increment only when
> a device does not respond. As long as a device
> responds before the timeout period I see the expNN
> number does not increase. As soon as a device
> doesn't respond the expNN count goes up and I can't
> figure out why. Once I hit a certain expNN the
:: 'close $spawn_id' is wrong, so maybe that's it?
:: man expect
:: close [-slave] [-onexec 0|1] [-i spawn_id]
:: closes the connection to the current process.
:: ... The -i
:: flag declares the
:: process to close corresponding to the named
:: spawn_id.
<.. snip ..>
I hand typed the close stuff in the email with just
'close spawn_id'. I did the -i in previous
iterations, but saw no difference. Maybe I should
try more. I saw the 'close' alone a lot on
Stackexchange a lot,so I was copying those in this
iteration. I also should have read the man page
more than I did, so a face slap to myself.
:: No matter whether the connection is closed
:: implicitly or explicitly, you should call wait to
:: clear up the corresponding kernel process slot.
:: close does not call wait since there is no guarantee
:: that closing a process connection will cause it to
:: exit. See wait below for more info.
:: The eof and timeout cases are basically
:: { catch {close}; catch {wait}; }
I always used wait after close and need to look into
those above. Maybe they close it different somehow.
:: get rancid from here... and take a look at clogin...
I'm going to be looking for a new job and want to up my
skills, in case I get a chance to do the SDN/NFV stuff,
which I read requires coding skills, so this is also an
exercise toward that. Plus it's fun.
I had already done this in PERL, but, even though we
have PERL, we are not allowed to download modules here.
So, I'm redoing it in Expect. I thought someone would
say a "oh just and you're done" type of
response.
Thanks a lot from everyone private and on the list.
I'll post for the archives if I find the answer.
scott
Re: using expect to log into devices
On 7/20/18, Scott Weeks wrote:
>
> I have looked extensively on the web for an answer
> and cannot find one, so I come to you guys. I am
> not allowed to use modules in PERL or Python or I
> wouldn't have to do it this way. I have to do this
> all in Expect and I am a newbie at it.
>
> Also, maybe I'm having the Friday afternoon "I want
> to go home" mental block and the answer is right in
> front of my nose.
>
> I have a file with 1000s of devices and another file
> with a list of commands. The program issues all
> commands for a device and then moves on to the next
> one using nested loops. In the debug I see the
> "spawn_id expNN" (where NN is a number that, I
> believe is representative of the number of file
> descriptors used in the system) increment only when
> a device does not respond. As long as a device
> responds before the timeout period I see the expNN
> number does not increase. As soon as a device
> doesn't respond the expNN count goes up and I can't
> figure out why. Once I hit a certain expNN the
> program exits ungracefully; usually somewhere between
> 2500 and 3500 devices because our FD is set to 256
> and that's how long it takes for 256 devices to not
> respond before the timeout period. Can anyone tell
> me why? Here is the relevant config snippet. I've
> tried every iteration of close and wait I found and
> no love...
'close $spawn_id' is wrong, so maybe that's it?
man expect
close [-slave] [-onexec 0|1] [-i spawn_id]
closes the connection to the current process. ... The -i
flag declares the
process to close corresponding to the named spawn_id.
<.. snip ..>
No matter whether the connection is closed implicitly or
explicitly, you
should call wait to clear up the corresponding kernel process
slot. close
does not call wait since there is no guarantee that closing a process
connection will cause it to exit. See wait below for more info.
get rancid from here
ftp://ftp.shrubbery.net/pub/rancid/
and take a look at clogin
(which allows you to do 'clogin -x fileName dev1 dev2 ... devN' to
run the commands
in 'fileName' on the list of devices)
The eof and timeout cases are basically
{ catch {close}; catch {wait}; }
Regards,
Lee
>
> You'll want to put this into a fixed width font like
> Courier New or it'll just be a mess.
>
>
> foreach element $device {
>
> send_user "\n\n"
>
> send_user "#\n"
> send_user "## BEGIN $element ###\n"
> send_user "#\n"
>
>spawn ssh -q -o StrictHostKeyChecking=no $username@$element
>
> expect {
> timeout { send_user "\nfailed to get password prompt\n\n"
> send_user "#\n"
> send_user "### END $element \n"
> send_user "#\n"
> send_user "\n\n\n"; continue
> close $spawn_id
> wait
> }
> eof { send_user "\nssh failure for $element\n\n"
> send_user "#\n"
> send_user "### END $element \n"
> send_user "#\n"
> send_user "\n\n\n"; continue
> close $spawn_id
> wait
> }
> "assword" {
> send "$password\n"
> }
>}
>
>
> expect {
> timeout { send_user "\npassword did not work or enable mode not
> achieved\n\n"
> send_user "#\n"
> send_user "### END $element \n"
> send_user "#\n"
> send_user "\n\n\n"; continue
> close $spawn_id
> wait
> }
> eof { send_user "\npassword failure for $element\n\n"
> send_user "#\n"
> send_user " END $element #\n"
> send_user "#\n"
> send_user "\n\n\n"; continue
> close $spawn_id
> wait
> }
> "" {
> send "term len 0\n"
> # send "skip-page-display\n"
>
> foreach command $commands {
> expect "#"
> send "$command\n"
> send_user "\n\n"
> }
> }
>}
>
> send "exit\n"
> send "exit\n"
>
> send_user "#\n"
> send_user "### END $element \n"
> send_user "#\n"
> send_user "\n\n\n"
>
> close
> wait
> }
>
>
> Thanks!
> scott
>
> ps; I realize my indenting of the curly braces and other
> things are not standard... :)
>
>
Re: using expect to log into devices
--- jwbens...@gmail.com wrote: From: James Bensley :: Do you need to write this yourself, No, but I'm tired of being a coding wussie, so this is 1) an exercise for me in getting better at it and 2) I want it to read a list of machines from one file and execute a list of commands from another. Then I just vi the files and done. :: I've used this expect script too many :: times such that I should be ashamed...It :: "just works": :: :: https://sourceforge.net/projects/cosi-nms/files/ciscocmd/ Thanks, it's beertime Friday, so I will look at it tomorrow. However, I'd sure like to know why I an using up all the file descriptors on the system. scott
Re: using expect to log into devices
Do you need to write this yourself, I've used this expect script too many times such that I should be ashamed...It "just works": https://sourceforge.net/projects/cosi-nms/files/ciscocmd/ Cheers, James.
using expect to log into devices
I have looked extensively on the web for an answer
and cannot find one, so I come to you guys. I am
not allowed to use modules in PERL or Python or I
wouldn't have to do it this way. I have to do this
all in Expect and I am a newbie at it.
Also, maybe I'm having the Friday afternoon "I want
to go home" mental block and the answer is right in
front of my nose.
I have a file with 1000s of devices and another file
with a list of commands. The program issues all
commands for a device and then moves on to the next
one using nested loops. In the debug I see the
"spawn_id expNN" (where NN is a number that, I
believe is representative of the number of file
descriptors used in the system) increment only when
a device does not respond. As long as a device
responds before the timeout period I see the expNN
number does not increase. As soon as a device
doesn't respond the expNN count goes up and I can't
figure out why. Once I hit a certain expNN the
program exits ungracefully; usually somewhere between
2500 and 3500 devices because our FD is set to 256
and that's how long it takes for 256 devices to not
respond before the timeout period. Can anyone tell
me why? Here is the relevant config snippet. I've
tried every iteration of close and wait I found and
no love...
You'll want to put this into a fixed width font like
Courier New or it'll just be a mess.
foreach element $device {
send_user "\n\n"
send_user "#\n"
send_user "## BEGIN $element ###\n"
send_user "#\n"
spawn ssh -q -o StrictHostKeyChecking=no $username@$element
expect {
timeout { send_user "\nfailed to get password prompt\n\n"
send_user "#\n"
send_user "### END $element \n"
send_user "#\n"
send_user "\n\n\n"; continue
close $spawn_id
wait
}
eof { send_user "\nssh failure for $element\n\n"
send_user "#\n"
send_user "### END $element \n"
send_user "#\n"
send_user "\n\n\n"; continue
close $spawn_id
wait
}
"assword" {
send "$password\n"
}
}
expect {
timeout { send_user "\npassword did not work or enable mode not
achieved\n\n"
send_user "#\n"
send_user "### END $element \n"
send_user "#\n"
send_user "\n\n\n"; continue
close $spawn_id
wait
}
eof { send_user "\npassword failure for $element\n\n"
send_user "#\n"
send_user " END $element #\n"
send_user "#\n"
send_user "\n\n\n"; continue
close $spawn_id
wait
}
"" {
send "term len 0\n"
# send "skip-page-display\n"
foreach command $commands {
expect "#"
send "$command\n"
send_user "\n\n"
}
}
}
send "exit\n"
send "exit\n"
send_user "#\n"
send_user "### END $element \n"
send_user "#\n"
send_user "\n\n\n"
close
wait
}
Thanks!
scott
ps; I realize my indenting of the curly braces and other
things are not standard... :)
