Terraform - A managed resource has not been declared in the root module

Question

i'm trying create ec2 instance and setup load balancer using terraform but i'm facing follwing error. How to create instance and configure load balacer in a single main.tf file?

Error: Reference to undeclared resource

"aws_lb_target_group" "front-end":27: vpc_id = "${aws_vpc.terrafom-elb.id}" A managed resource "aws_vpc" "terrafom-elb" has not been declared in the root module.source`

code:

  region = "us-east-1"
  access_key = "*********************"
  secret_key = "**********************"
}

resource "aws_instance" "terraform" {
  ami           = "ami-07ebfd5b3428b6f4d"
  instance_type = "t2.micro"
  security_groups    = ["nodejs","default"]
  tags = {
    Name = "terrafom-elb"
  }
}

resource "aws_lb" "front-end"{
  name = "front-end-lb"
  internal = false
  security_groups    = ["nodejs"]

}

resource "aws_lb_target_group" "front-end" {
  name     = "front-end"
  port     = 8989
  protocol = "HTTP"
  vpc_id   = "${aws_vpc.terrafom-elb.id}"
  depends_on = [aws_instance.terraform]
}

There is indeed no aws_vpc resource in this config. Can you share the rest of your config that contains it? — Matt Schuchard
or maybe is it a data source that you want to use ? in that case you may use data.aws_vpc.terraform_elb instead. if not, Matt is right, the rest of the config is needed to understand the issue — nulse

MJe MJe · Accepted Answer · 2020-10-05T04:42:40

You can add a data structure to the top and pass VPC ID as variable:

data "aws_vpc" "selected" {
  id = var.vpc_id
}

And reference it as vpc_id = data.aws_vpc.selected.id

Terraform - A managed resource has not been declared in the root module

2 Answers