[noctool-devel] compact configurations for identical machines

[Ingvar]

Jim writes:
> I was thinking about what a bear it will be to have to specify each of my 
> compute node systems in my clusters individually.
> 
> I was thinking about syntax such as the following that would create an 
> equipment object for each of 256 hosts named l001 through l256.
> 
> (machine-cluster "LosLobos" linux-host
>   (user "download")
>   (disks
>    (disk "/dev/sda1" 80 95))
>   (machinerange "l001-l256"))

It is definitely a cool idea. I am not ENTIRELY sure what the best syntax for 
the name range would be, but it's definitely something that would be handy for 
many users.
 
> What do y'all think?  Is there a better way to do this?  Something like 
> this would reduce the size of my shop's config file a couple orders of 
> magnitude - in turn, I'd screw things up accordingly less often :)

At the moment, you could PROBABLY use LOOP and friends, but that'd be icky. 
The whole config file is a chain of macros expanded to code generating 
configuration objects. On further consideration, no, you can't (yes, I tested, 
no you're not supposed tio, it seems it worked...).

I was actually thinking, the other day, that the current config-nesting only 
allows a nested macro to use a single context and I was trying to thing of a 
use-case where one would want stuff nested in more than one and now I have one.

I'll get the changes necessary for defnested sorted before heading off to 
work. I suspect a workable method for naming the individual hosts would be a 
"member-name" config stanza, taking (say) a format-string (either C or CL, we 
should eb able to compile the former to the latter), a start number and an end 
number. I feel that making sure you do the right thing for something like 
"l001-l256" is just plain hard in the general case.

Imagine trying t figure out how many hosts and what they SHOULD be called when 
faced with something like "rtr-f01-001-rtr-f03-999". Is that 999 routers, 333 
named "...f01...", 3 routers, named "...f01-001", "f02-500" and "...f03-999" 
or 2997 routers? I could make a case for all of those. :) I also suspect we 
only want to support a single range, to make things MUCH easier.

//Ingvar