[rancid] "show env all" vs. "show env" on Cisco IOS

[Terry Kennedy]

  I'm trying to monitor power supply / fan status on assorted Cisco gear.
However, the Cisco CLI is inconsistent (so, what else is new?) across the
various platforms.

  Here is a brief summary (all running their respective latest IOS - 15
for everything except the 4948, 3750 and 2651XM, which are running 12).
"Expected output" indicates a full (for that platform) report, while any-
thing else is the error message or one-line status:

  Platform		    "show env all"		"show env"
  ---------------------	    ------------------------	--------------------
  Catalyst 4500X-16SFP+	    "Invalid input detected"	Expected output
  Catalyst 4948-10GE	    "Invalid input detected"	Expected output
  Catalyst 3750-48TS	    Expected output		"Incomplete command"
  3845			    Expected output		Expected output
  7206VXR / NPE-1	    Expected output		"All measured values
							are normal"
  ASR1000		    Expected output		Expected output
  2651XM		    Expected output		Expected output
  ASA5506		    "Invalid input detected"	Expected output

  Some platforms only accept "show env all", some only accept "show env",
some accept both and produce identical output and some accept both and
produce different output.

  It seems that "the right thing" would be to try the "show env all" and
only if that reports an error, try "show env". Simply sending both com-
mands would seem to risk duplicate lines in the RANCID file for the cases
where the device returns the same data for both commands, or a spurious
"All measured values are normal" if it accepts both commands but returns
different data.

  I could clone the cisco device from rancid.types.base into multiple
different sub-device types in rancid.types.conf, but that means a lot
of extra work dealing with new RANCID versions. But that has the advan-
tage of not having to parse wildly different output types in the same
routine.

  What would be great is if rancid.types.conf had an "inherit" state-
ment that would let me include a device type from rancid.types.base
and then let me add (or possibly remove) commands, something like this:

cisco-env;inherit;cisco
cisco-env;command;ios_local::ShowEnv_local;show env

cisco-no-env;inherit;cisco
cisco-no-env;nocommand;;show env all

  Has anybody waded through this morass previously and come up with a
good solution?

        Terry Kennedy             http://www.tmk.com
        terry at tmk.com             New York, NY USA