First pass of a way of handling multiple apcupsd hosts.

[cyberfox]

An example yaml file that would satisfy this would look like this:

address: 0.0.0.0:9175
hosts:
  - address: 10.0.1.64
    port: 3551
    slug: ml-server
  - address: 127.0.0.1
    port: 3551
    slug: greybox

Without a slug defined, it will default to adding apcupsd{#} to the front of the metrics lines, otherwise it adds the slug.

This version changes the behavior; I can make it so that if there isn't a 'hosts' section, it doesn't prefix anything at all. I may also make it so it accepts hostnames instead of ports, but this works for me really well.

This is (literally) the first Rust code I've ever written, and even read more than a few lines of. My apologies if I've messed something up. The compiler is really surprisingly helpful. :)

Caveat: Once I had it entirely working by hand (only way to learn), I put it into a language model to ask if it was idiomatic, and it suggested some changes. I made some of them manually, and decided not to for others because they fit the style of the existing code more. It did show me how to clean up my absolute mess of clones, as_refs, '&'s and such, which I appreciated. 😅

[AndrolGenhald]

Thanks for the interest!
I'm trying to understand the motivation here a bit, it would make sense to me to add support for exporting multiple UPSes connected to a single host, but it looks like this is adding support for extracting data from apcupsd on multiple separate hosts to export from a central host? Is there a reason you can't just run another copy of the exporter on the 10.0.1.64 host? This feels like it might be an XY problem that could be better solved somewhere else.

[9p4]

I think that this approach is incorrect: there should be labels for the new hosts, not prefixes. Take a look at our fork: purdueLUG/prometheus_exporter_apcupsd@ea49422