m1-terraform-provider-helper VS terraform-aws-ssh-bastion-service

There's virtually no unsolved issue. If you need something x86 is you use rosetta. If you're using terraform and a provider hasn't issued an ARM release you can use the m1 provider helper.

There really isn't any substitute for production experience. Yes you can learn the basics, and the universals are transferable, but you're never going to come across e.g. something like needing this in a homelab, still less the real reasons why you need it...

Try this. https://github.com/kreuzwerker/m1-terraform-provider-helper

tfswitch might help with particular issue of terraform versioning:

https://tfswitch.warrensbox.com/

Even then some versions of terraform providers are not compatible with M1 macs. Docker would help with that probably, but so can: https://github.com/kreuzwerker/m1-terraform-provider-helper

Perhaps these sort of issues support the benefits of per-module docker images?

Check to see if your provider has an M1 compiled version https://github.com/kreuzwerker/m1-terraform-provider-helper/blob/main/docs/provider_information.md

The general availability of darwin_arm64 Terraform providers. There are often cases where the maintainers did not release a darwin_arm64 version yet. Only roughly a fourth of all providers have a darwin_arm64 version released (see here for details)

I'm not sure from this exactly what you're trying to do. If you're working with cloudinit/userdata then I can point you to an example.

I actually mashed together cloudposse/terraform-aws-dynamic-subnets (which has an option to use NAT instances instead of gateways) and joshuamkite/terraform-aws-ssh-bastion-service. That allowed for even cheaper setups where your bastion jump-host (the host you proxy through to get to the private subnets) is also the NAT gateway. I quite liked this setup because the bastion sessions were sufficiently sandboxed in a ephemeral container, and we didn't need twice the number of hosts to have both NAT instances and bastions.

I have a public terraform module which i migrated away from the template provider last year. You can see how I handled the changes and used the new provider if that helps

You should try to avoid using remote exec with terraform wherever possible. It's not a great fit with the declarative approach that Terraform aims for. Here you would be better off using 'user data' to provision your instance. I have a public project that deploys and builds a Golang app on EC2. It's a bit more complicated than your example here, but it does demonstrate a method for doing what you're trying to do with the approach that I have suggested.

The thing that really moved me on from junior to senior in this area was finding something that was a common pain point for many people that I could focus on to address as a 'simple' solution that could be used as a 'black box' or 'tick box'. Once it picked up steam I had to deal with other people's use cases and suggestions that I had never considered before, both in person (when i spoke at meetups) and online (open source project).

It looks like you might be misunderstanding the purpose of the yamlencode function here. Terraform doesn't need to know anything about the syntax of the file you're using with templatefile, as long as it's text, you're good. Just start with a yaml file and use the templatefile syntax for your substitutions. Examples

I have a public Terraform module with releases incrementing from tf 11 thru 1.2.0 where you can see changes dealing with this sorry of thing

I'm well aware. My repo that I linked is in multi part mime. An older version used different mime types but I couldn't get it to handle all the conditional logic reliably

I haven't seen your code but it sounds like you're using it wrong. I can well imagine that if you apply multiple cloudinit_config files to a single host that they get placed in alphabetical order but I don't really get why you would want to do that. In many environments, e.g. AWS, you can only supply a single user data file to your host anyway. cloudinit_config supports mullti-part MIME encoding so that you can combine sections from multiple sources in a predictable way.

You can see terraform rendering IAM policies with interpoalted assume role policies in my module.