[rancid] Random behavior of $found_end and $clean_run

[heasley]

Thu, Jan 12, 2017 at 11:08:46PM +0100, Stefan Midjich:
> Excluse my ignorance in Perl but I've observed some very strange
> behavior on Ubuntu 16.04 with Rancid 3.3.
> 
> I've also tried patching relevant files with new code from the latest
> rancid 3.6.2 package and seeing same results.
> 
> Rancid-run mostly reports that $found_end or $clean_run are zero but
> if I insert a print around line 180 suddenly the variables are
> magically set.
> 
> I've run several times and only once was clean_run set to 0. But if I
> remove the print, it goes back to reporting "End of run not found".
> 
> I also tried setting it in ciscowlc.pm but there I can see that
> found_end and clean_run are mostly set to 1.
> 
>     # WLC lacks a definitive "end of config" marker.
>     if ($linecnt > 5) {
>         print STDERR "Found end, return 1" if ($debug);
>         $found_end = 1;
>         return(1);
>     }
> 
> And changed my /etc/rancid/rancid.types.conf setup to this.
> 
> cisco-wlc8;script;rancid -d -t cisco-wlc8
> cisco-wlc8;login;wlogin -noenable -t 120
> cisco-wlc8;module;ciscowlc
> cisco-wlc8;inloop;ciscowlc::inloop
> cisco-wlc8;command;ciscowlc::ShowUdi;config paging disable
> cisco-wlc8;command;ciscowlc::ShowUdi;show udi
> cisco-wlc8;command;ciscowlc::ShowSysinfo;show sysinfo
> cisco-wlc8;command;ciscowlc::ShowConfig;show run-config
> 
> So I could see the debug info, and sure enough it hits the end but
> doesn't register.
> 
>     Exiting ShowConfig: (Cisco Controller) >
>  Found End, return 1
> wlc01: End of run not found
> 
> Also note that the double ShowUdi is a hack for Cisco WLC version 8
> where you need to disable paging.

Doesn't 'config paging disable' change the configuration of the device,
rather than just the current session?  And, is wlogin not responding to
the pager properly?

also, you can use a different function to eat the output:

cisco-wlc8;command;rancid::RunCommand;config paging disable

> Vanilla code with debug flag gives me this at the end of the log.
> 
> wlc01: End of run not found
> wlc01: End of run not found
> !--WLC End Config Data--!
> 
> Then I add this line on line 141 of /usr/lib/rancid/bin/rancid.
> 
> print(STDERR "$found_end, $clean_run\n") if ($debug);
> 
> And rancid-run says this at the end of the log.
> 
> 1, 0
> wlc01: End of run not found
> wlc01: End of run not found
> 
> But I've added a print statement next to every instance of clean_run =
> 0 I could find in ciscowlc.pm yet I don't see any of them in the log.
> 
> And this behavior somtimes shifts to both values being 1, and no error
> being shown.
> 
> It's unusually random and I cannot figure out what is causing this
> behavior. Has anyone observed this?
> 
> I've documented my wlc v8 config here in case it might help anyone:
> https://wiki.sydit.se/teknik:guider:networking:backup_av_cisco_wlc_med_rancid
> 
> -- 
> Vänliga Hälsningar / Sincerely
> Stefan M
> 
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