Support tagged lookups on VPC & Subnets

[jasonmcintosh]

For systems NOT using the default vpc (e.g. using the terraform vpc module), there are often public and private subnets created. This means 6 subnets 2 per AZ, which breaks this module. One thought is to add a variable

variable "subnet_tags" {
##   Tier = "Private"

}

and modify main.tf to do

data "aws_subnet_ids" "default" {
  vpc_id = "${data.aws_vpc.default.id}"
  tags = "${var.subnet_tags}"
}

Then apply similar logic to the aws_vpc block

[brikis98]

Assuming that Terraform treats an empty tags value the same as no value at all, I'm definitely in favor of this change!

[jasonmcintosh]

:) NULL != 0 != "" != [] != {} :)

[brikis98]

Haha, yep. I even filed a bug about it: hashicorp/terraform#14037

[jasonmcintosh]

#39 :)

[patoarvizu]

#39 Adds support for tagged lookups on the main "example", but not on the vault-cluster module, which is where I think would be more valuable, since the main example is not one-size-fits-all. Plus I don't think examples are supposed to be considered production-ready anyway (or at least they should be considered less production-ready than modules). I'll open an issue for it.

EDIT: I meant open a PR, as soon as I have one :)

[jasonmcintosh]

@patoarvizu vpc_id in the vault-cluster module is just a variable. It's up to the client depending on it as a module to set it. Either through a data lookup or similar. The main is an example implementation of how to do so. In theory, you could pass a set of filters or tags instead of the vpc_id but that starts to complicate the module. This way you can do any of the available options.