Output Name tag of ALL EC2 instances of all types

Terraform
1

Hello All,

I have several sets of resources of the aws_instance type, e.g. N nginx instances, M php instances etc. I would like to create an output which will print the names of all instances of all types.

It is easy to output all intances of one type:

output "ec2_instances" {
  description = "Names of EC2 instances"
  value       = aws_instance.nginx.*.tags.Name
}

but how can I output really all types in one output? A construction like aws_instance.*.*.tags.Name does not pass validation.

2

Does this match your purpose?


data "aws_ami" "ubuntu" {
  most_recent = true

  filter {
    name   = "name"
    values = ["ubuntu/images/hvm-ssd/ubuntu-focal-20.04-amd64-server-*"]
  }

  filter {
    name   = "virtualization-type"
    values = ["hvm"]
  }

  owners = ["099720109477"] # Canonical
}

resource "aws_instance" "nginx" {
  ami           = data.aws_ami.ubuntu.id
  instance_type = "t3.micro"

  tags = {
    Name = "ec2-nginx"
  }
}

resource "aws_instance" "php" {
  count = 2   // create multi instances
  ami           = data.aws_ami.ubuntu.id
  instance_type = "t3.micro"

  tags = {
    Name = "ec2-php-${count.index + 1}"
  }
}

output "ec2_instances" {
  description = "Names of EC2 instances"
  value       = concat(aws_instance.nginx.*.tags.Name, aws_instance.php.*.tags.Name)
}

applied:

Outputs:

ec2_instances = [
  "ec2-nginx",
  "ec2-php-1",
  "ec2-php-2",
]
3

Hello @JHashimoto0518 !

You are still enumerating instance types in concat(aws_instance.nginx.*.tags.Name, aws_instance.php.*.tags.Name) (i.e. you explicitly mention “nginx”, “php” etc) but I would like to avoid that. The whole purpose is to output all instances no matter of their type because enumerating does not scale well.

4

Hello @victor-sudakov,

I understood your situation. Unfortunately, I do not know how.

5

Neither do I. Somehow I need to iterate over aws_instance.* but don’t know how.

6

Terraform does not provide any way to do that, so you are required to reference each block explicitly.

7

Terraform does not provide any way to do that, so you are required to reference each block explicitly.

That’s unfortunate, but thank you @maxb for letting me know. At least I’ll stop looking for a solution which obviously does not exist.