terraform is logical but not natural

The subject kind of says it all. If you can use environment variables (and you can and probably should) in terraform with the invocation/usage of TF_VAR_environment_variable_name, why in the ever loving world can you not do the same in modules (or sub-modules as I think of them)? Apparently environment variables don't propagate into the submodules.

So, you basically "re-declare" when you define/invoke the submodule. See: https://stackoverflow.com/questions/53853790/terraform-how-to-pass-environment-variables-to-sub-modules-in-terraform

In my case, I'm building "N" VMs in submodules and there is a "vms.tf" that has the "module "NAME" {} invocation (and of course there are "N" of these) so I had to do something like:

module "FIRST" {variableone = var.variableone}

.

.

.

module "NTH" {variableone = var.variableone}

"N" times and then at the top level (main.tf or variables.tf) something like:

variable "variableone" {
  description = "Cascade environment variable in terraform"
  default = ""

}

and then
export variableone="myvaluegoeshere"

in my environment.

It's been a minute and a few years....

 So, I just noticed it's been a minute since I last posted. I typically only post things that I need to find again in the future--and apparently that's been less often lately.

Today, I needed to figure out WHY IN THE WORLD my LG 4K HDMI monitor was popping throughout the day. And, indeed I did, but first, how did I get here?

I am a longtime Ubuntu user. This machine was built with Ubuntu in 2017-11 and upgraded to LTS release in 2018. I do daily apt updates but recently bit the bullet and brought it up to 2020 LTS release. That went very well and I see a number of improvements. However, it also started making a LOUD popping noise that I couldn't tie to any particular user activity.

A bit of googling later and I found that it was likely related to snd_hda_intel module and its power_save settings. power_save defaults to 1 (on this machine and similar) as it is a laptop and power_save is a good thing for a laptop. However, 98% of the time, it is now running primarily as a desktop. You know, COVID-19 and nowhere to go....

I confirmed the issue by further googling and found my friend Major Hayden's post when I ran into this same thing: https://major.io/2019/03/04/stop-audio-pops-on-intel-hd-audio/ it has a better writeup, more detail etc. But I post here so that I can easily find this myself for future me. I also thanked past Major here: https://twitter.com/davidmedberry/status/1371588276176363521