How to use dynamic resource names in Terraform?

Question

I would like to use the same terraform template for several dev and production environments.

My approach: As I understand it, the resource name needs to be unique, and terraform stores the state of the resource internally. I therefore tried to use variables for the resource names - but it seems to be not supported. I get an error message:

$ terraform plan var.env1   Enter a value: abc  Error asking for user input: Error parsing address 'aws_sqs_queue.SqsIntegrationOrderIn${var.env1}': invalid resource address "aws_sqs_queue.SqsIntegrationOrderIn${var.env1}" 

My terraform template:

variable "env1" {}  provider "aws" {         region = "ap-southeast-2" }  resource "aws_sqs_queue" "SqsIntegrationOrderIn${var.env1}" {         name = "Integration_Order_In__${var.env1}"         message_retention_seconds = 86400         receive_wait_time_seconds = 5 } 

I think, either my approach is wrong, or the syntax. Any ideas?

Answer 1

You can't interpolate inside the resource name. Instead what you should do is as @BMW have mentioned in the comments, you should make a terraform module that contains that SqsIntegrationOrderIn inside and takes env variable. Then you can use the module twice, and they simply won't clash. You can also have a look at a similar question I answered.

Answer 2

I recommend using a different workspace for each environment. This allows you to specify your configuration like this:

variable "env1" {}  provider "aws" {         region = "ap-southeast-2" }  resource "aws_sqs_queue" "SqsIntegrationOrderIn" {         name = "Integration_Order_In__${var.env1}"         message_retention_seconds = 86400         receive_wait_time_seconds = 5 } 

Make sure to make the name of the "aws_sqs_queue" resource depending on the environment (e.g. by including it in the name) to avoid name conflicts in AWS.