Error: Reference to undeclared resource (dependency) lambda and apigateway

[Assassin010]

Apigw module is dependent to lambda module,

It look like terragrunt is not able to retrieve outputs from the state and parse it to dependency in terragrunt.hcl under apigw folder

Terragrunt codes:

.
├── apigw
│ └── terragrunt.hcl
├── env.hcl
├── graph.svg
└── lambda
├── lambda
│ ├── lambda_handler.zip
│ └── src
│ └── main_lambda.py
└── terragrunt.hcl

Modules (terraform codes) below:

├── apigw
│ ├── main.tf
│ └── variables.tf
└── lambda
├── main.tf
├── outputs.tf

--Output under lambda module
output "function_name" {
value = aws_lambda_function.auto-start.function_name
}

output "invoke_arn" {
value = aws_lambda_function.auto-start.invoke_arn
}

---------Error below when I run terragrunt run-all apply

╷
│ Error: Reference to undeclared resource
│
│ on main.tf line 59, in resource "aws_api_gateway_integration" "MyDemoIntegration":
│ 59: uri = aws_lambda_function.auto-start.invoke_arn
│
│ A managed resource "aws_lambda_function" "auto-start" has not been declared
│ in the root module.
╵
╷
│ Error: Reference to undeclared resource
│
│ on main.tf line 111, in resource "aws_lambda_permission" "api_gw":
│ 111: function_name = aws_lambda_function.auto-start.function_name
│
│ A managed resource "aws_lambda_function" "auto-start" has not been declared
│ in the root module.

My main.tf under apigw module look like this
Line 59 (uri)

resource "aws_api_gateway_integration" "MyDemoIntegration" {
rest_api_id = aws_api_gateway_rest_api.testAPI.id
resource_id = aws_api_gateway_resource.testresource.id
http_method = aws_api_gateway_method.testMethod.http_method
integration_http_method = "POST"
uri = aws_lambda_function.auto-start.invoke_arn
type = "AWS"
passthrough_behavior = "WHEN_NO_TEMPLATES"

tags = local.tags
}

Line 111 (function_name)
resource "aws_lambda_permission" "api_gw" {
statement_id = "AllowExecutionFromAPIGateway"
action = "lambda:InvokeFunction"
function_name = aws_lambda_function.auto-start.function_name
principal = "apigateway.amazonaws.com"
source_arn = "${aws_api_gateway_rest_api.testAPI.execution_arn}//"

tags = local.tags

}

NOW my terragrunt.hcl under apigw folder

dependencies {
paths = ["../lambda"]
}

dependency "lambda" {
config_path = "../lambda"
}

inputs = {
function_name = dependency.lambda.outputs.function_name
invoke_arn = dependency.lambda.outputs.invoke_arn
env = local.env
}

include {
path = find_in_parent_folders()
}

---

Tracked in ticket #110026

[denis256]

Hello,
from the description is not clear how terragrunt was invoked:

• terragrunt run-all apply - will apply dependencies and take outputs
• terragrunt apply - will evaluate only the local directory (most probably will fail on fetching outputs if no previous runs executed which generated outputs)

I prepared a simplified example with passing variables in https://github.com/denis256/terragrunt-tests/tree/master/discussion-689, I hope it will be useful

[Assassin010]

Thanks mate, variables were missing. All good now🤗