handle IPMI setup error for LAN port

[rsmitty]

From a community user, seeing the error:

[sidero] Attempting to automatically discover and configure BMC
[sidero] encountered error discovering BMC IP. Skipping setup: "run /usr/sbin/ipmitool ipmitool -H -U -I open -E raw 0x0c 0x02 0x01 0x08 0x00 0x00: Unable to send RAW command (channel=0x0 netfn=0xc lun=0x0 cmd=0x2 rsp=0x80): Unknown (0x80)\n (exit status 1)"

This is caused by our request for the port on this line: https://github.com/siderolabs/sidero/blob/master/app/sidero-controller-manager/cmd/agent/main.go#L407, which receives an 0x80 hex response that means parameter not supported. Seems to me that this means that either the Intel IPMI implementation doesn't support getting this value or maybe it's for "authenticated sessions" only (which is something I saw mentioned online).

I think we may just need to catch this error and set the value to the default port if we get it. I'm not totally sure if it would result in a subsequent failure though if the port is actually not the default and we just can't read it.

The default value is Default = 26Fh (RMCP ‘Aux Bus Shunt’ port).

[magicite]

There was more discussion on this on the sidero slack last fall, but that has aged out so I thought I'd add in some of those learnings here for posterity. The real issue here might have been related to the multi-channel BMC capabilities of the node in question - an Intel S2600WF which can use any/all of a dedicated BMC or host NIC ports for BMC functionality.

I think on our configuration we were using the dedicated BMC (channel 3?) but the SIdero code was assuming/poking at channel 0 or 1 (not sure which). Since that channel wasn't configured in the BMC, when Sidero requested the info it got the error referenced in the original report.

So maybe the fix is looping through channels until it finds the first one that works?