redfishpower: add -x,--exclude-plugs option

[garlick]

Problem: it's kind of janky to have to make up hostname placeholders like unused[0-7] for unused blade slots in the cray-ex chassis.

I can't remember if we discussed this before and decided against it, but would it make sense to have a redfishpower -x,--exclude-plugs option so those placeholders would not be needed? For example if Blade[4-7] are unpopulated thus Node[8-15] do not require host mappings, instead of:

device "chassis0" "cray-ex" "/usr/sbin/redfishpower -h cmm0,pnode[0-7],unused[0-7] |&"

you could do:

device "chassis0" "cray-ex" "/usr/sbin/redfishpower -x Node[8-15] -h cmm0,pnode[0-7]|&"

[chu11]

My initial thought was "does it actually make the config easier?" It seems like a sideways move to me overall.

[garlick]

What could go wrong :-) . Why is my misconfigured powerman daemon sending http requests to "unknown15"?

[chu11]

per some offline thoughts / discussion

implementation can get a little tricky, b/c of parenting. for example, if user does --excldude=Blade6, that means that not only Blade6 is not a valid plug, but Node12 & Node13 are also invalid.

Hypothetically making it so exclude only works with "leaf" plugs makes things easier, but there's no way to know what a leaf is until all configuration is complete (which is in login script, well after command line parsing is done).

[chu11]

A completely random, possibly bad idea. What if we made a certain keyword a special case for "unused". Like

-h cmm0,pnode[0-7],UNPOPULATED[0-7]

and redfishpower would know "never send a message to UNPOPULATED"?

[garlick]

Eh, that still feels pretty hacky for me.