How to apply count index on provider aws of terraform?

Question

I want to create 3 ec2 instances in 3 different regions. I am using iteration and count index feature of terraform. But I am not able to apply the same feature for region parameter in aws provider.

provider "aws" {
  region = "${element(var.region, count.index)}"
}

Where I am passing the values like below.

region = [ "us-east-1" , "eu-central-1" ]
instance_type = [ "t2.small" , "t2.micro" ]

I am getting following error after terraform init.

count variables are only valid within resources

As the error message says, you can't do that. You need to specify separate aliases for each anyway. — ydaetskcoR
forgot to mention, but I would like to have a generic solution. Adding aliases means hardcoding fix regions. — Sandip Divekar
Yep, and unfortunately that's a limitation of Terraform. It might be better if you could expand on what your requirements are and maybe there's a better solution. — ydaetskcoR
Hmm. As I have multi-region deployment so now generating separate terraform.tfvars file for each region. Thanks buddy @ydaetskcoR — Sandip Divekar

Shiv Rajawat Shiv Rajawat · Accepted Answer · 2018-10-04T14:06:20

The region to be entered in the provider block should be your default region. Since, there is only one default region per aws user, it can't accept a list of regions.

Try giving region as:

region = "${var.region[0]}"

It takes the first element of list of regions that you have specified as variables. Accordingly, you can change the index to point to some other element of the list.

How to apply count index on provider aws of terraform?

1 Answers