Hi everyone,
I am new to terraform. I have a ques...
# terraformd
Dallas Despain
10/14/2024, 10:56 PMHi everyone,
I am new to terraform. I have a question about how to get an ARN from a resource that is created by a module. For example the AWS Lambda module. If I create a lambda using that module how do I reference the ARN for the lambda? This is how I reference the module in my codebase:
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module "build_teams_notify" {
source = "terraform-aws-modules/lambda/aws"build_teams_notify. aws_lambda_function.arnt
Troy Knapp
10/14/2024, 11:11 PM@Dallas Despain you need to reference it via an output from the module.
In the module:
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output "aws_lambda_function_arn" {
value = aws_lambda_function.arn
} Copy code
locals {
my_important_arn = module.build_teams_notify.aws_lambda_function_arn
# my_important_arn = module.build_teams_notify.<name of the output you created in the module>
}d
Dallas Despain
10/15/2024, 2:50 PMThank you @Troy Knapp!
Dallas Despain
10/15/2024, 6:36 PM@Troy Knapp ugh... I feel like this is a very ignorant question, but when I put "in the module" I'm thinking it's inside the module block, but that must not be right because when I put this in the module block
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output "aws_lambda_function_arn" {
value = aws_lambda_function.arn
} Copy code
│ Error: Unsupported block type
│
│ on <http://notify.tf|notify.tf> line 3, in module "build_teams_notify":
│ 3: output "teams_notify_aws_lambda_function_arn" {
│
│ Blocks of type "output" are not expected here.
╵Dallas Despain
10/15/2024, 6:37 PMWhen I try to put it after the module block it says
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╷
│ Error: Reference to undeclared resource
│
│ on <http://notify.tf|notify.tf> line 85, in output "teams_notify_aws_lambda_function_arn":
│ 85: value = aws_lambda_function.arn
│
│ A managed resource "aws_lambda_function" "arn" has not been declared in the root module.
╵t
Troy Knapp
10/15/2024, 6:39 PMNo, your module block is referring to a package of terraform code. In that package you need to add an output.
Troy Knapp
10/15/2024, 6:40 PMHere's a pretty good breakdown of modules
https://spacelift.io/blog/what-are-terraform-modules-and-how-do-they-work
d
Dallas Despain
10/15/2024, 6:49 PMThanks again!
Dallas Despain
10/15/2024, 6:50 PMI thought that module block was referring to a module on the terraform registry
t
Troy Knapp
10/15/2024, 6:51 PMNo, the outputs already in the module are here:
https://registry.terraform.io/modules/terraform-aws-modules/lambda/aws/latest?tab=outputs
Troy Knapp
10/15/2024, 6:52 PMThis is probably what you want
d
Dallas Despain
10/15/2024, 7:37 PMSo would referencing it look something like this (using the locals block you mentioned)
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locals {
my_important_arn = terraform-aws-modules.lambda_function_arn
}t
Troy Knapp
10/15/2024, 7:41 PMyou're referencing a module, so you need that prefix, then you need the name of the module, then you need the output... which is how I wrote it
d
Dallas Despain
10/15/2024, 7:46 PMI got it!
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