│ Error: Unsupported attribute - This object has no argument, nested block, or exported attribute named "Name"

Terraform Providers AWS
1

trying to run this simple terraform script

variable "instance_count" {
    default = "1"
}

provider "aws" {
  region     = "us-west-1"
}

resource "aws_instance" "example" {
  ami           = "ami-0cf4a2d03d1a3d62c"
  instance_type = "t2.micro"
  key_name = "t2micro-1"
  subnet_id = "subnet-0d9d37440a2265163"
  security_groups = ["${aws_security_group.allow_rdp.Name}"]
}

resource "aws_security_group" "allow_rdp" {
  name        = "allow_rdp"
  description = "Allow ssh traffic"
  vpc_id      = "vpc-013c7c9a647b7342b"


  ingress {

    from_port   = 3389 #  By default, the windows server listens on TCP port 3389 for RDP
    to_port     = 3389
    protocol =   "tcp"

    cidr_blocks =  ["0.0.0.0/0"]
  }
}

but ghetting the error

Error: Unsupported attribute
│ 
│   on ec2.tf line 14, in resource "aws_instance" "example":
│   14:   security_groups = ["${aws_security_group.allow_rdp.Name}"]
│ 
│ This object has no argument, nested block, or exported attribute named "Name". Did you mean "name"?
╵
2

i changed it to

resource "aws_instance" "example" {
  ami           = "ami-0cf4a2d03d1a3d62c"
  instance_type = "t2.micro"
  key_name = "t2micro-1"
  subnet_id = "subnet-0d9d37440a2265163"
  security_groups = ["allow_rdp"]

but then got another error

Error: Error launching source instance: InvalidGroup.NotFound: The security group 'allow_rdp' does not exist in VPC 'vpc-013c7c9a647b7342b'
│       status code: 400, request id: e747fc43-28e1-4291-bee9-2d7bf01bd1ee
│ 
│   with aws_instance.example,
│   on ec2.tf line 9, in resource "aws_instance" "example":
│    9: resource "aws_instance" "example" {
3

Hi @tdubb123,

I think the typo mentioned in the error message is the main problem here: you need to write name with a lowercase n, not with an uppercase N:

  security_groups = [aws_security_group.allow_rdp.name]

(I also removed the "${ and }" syntax because that is only needed when you are combining multiple values together using a string template; there’s no need for that when you just want to use a single string value directly.

With that said, if I recall correctly security group names are only for EC2-Classic and so unless you have a very old AWS account you’ll probably need to use the vpc_security_group_ids argument instead, like this:

  vpc_security_group_ids = [aws_security_group.allow_rdp.id]

(Notice that for this argument we need to use the id attribute of the security group, rather than the name attribute. This is just a quirk of the differences between the legacy EC2-Classic and modern EC2; for modern EC2, security groups are always identified by a server-assigned ID rather than by the name you specified.)