enable use of multiple shelly plugs

[SoongJr]

This also includes some changes to the dashboard (to make the names of the plugs show up on the board), migrating the time series panel while doing so.
Please note the change from singular to plural in the variable names, which might make it harder to merge changes for others, but it felt to me like the right thing to do.

[SoongJr]

I just noticed this is basically a duplicate of the abandoned PR #232 addressing feautre request #118 😂 (plus changes to the dashboard, but using a single set of credentials for all plugs)
Sorry @alexandruz, I was not trying to "steal" your code and contribute it as my own, I just hadn't seen your PR before (should have checked the closed PRs before spending all that effort implementing it on my own, but at least I learned a lot). I do think my dashboard changes at least do provide some improvements over #232, so I'll keep it open and see what happens.

[geerlingguy]

My goal is to test this with multiple plugs, but even testing with one plug and seeing success would be good enough for me.

[DanForever]

How does this affect existing data?

[SoongJr]

Good question that @DanForever!
tl;dr: the data is not lost, worst case the old data shows as a seperate plug to the ones you actually have with the name "shelly-plug".

Details:
Anytime you rename a "job" in prometheus it remembers the old data under the old job name, so it's not lost. Previously the name of the job for the shelly plugs was hardcoded to "shelly-plug", though you may have modified that ;) Nw you can configure the name of each plug in config.xml, so if you give one of your plugs the exact same name it previously had, the transition is seamless.
If you want to give every plug a good name, the old and new data will be treated as different plugs (one of which you don't get any new data for), so you'll have an extra gauge that's useless (always displaying the last recorded value I believe) and an extra line in the diagram with the old data, until it ages out of the retention period.

I haven't actually deliberately tested that, but I've renamed jobs a couple times and got the old data showing up like that, so I'm confident it will happen as I've described.
From what I've read, getting rid of old data is no easy feat, so I always deleted the whole database to get rid of old jobs 😅

[DanForever]

Good to know @SoongJr! :)
Do you know how easy it would be to update the old data so that it follows the new naming scheme?
I realise I have no idea how this data is stored under the hood, or how to access or backup that data...

Also, I wanted to mention it here as it's tangentially related, I bought myself one of the new Shelly Plus 1PM relays, but it has a new API vs the old ones, so I've updated @geerlingguy's script for polling the shelly, and created a pull request here: geerlingguy/shelly-plug-prometheus#6

[SoongJr]

I can tell you the data is kept in a prometheus database inside the prometheus docker container. I'm new to this stuff myself, so all I can advise is to google "prometheus change job name" or something. All data is linked to a job and you want to rename that from shelly-plug to whatever new name you are giving it. Hope it works out, please share your findings if you manage to do it ;)

[DanForever]

Any news on this one?

[DanForever]

Thought I'd poke my head in as we approach the anniversary of my last comment 😁. @geerlingguy I know you're a busy man, have you thought about appointing a moderator/collaborator/[insert-correct-nomclamenture-here] to act in your stead?