How can I add a tag to AWS EBS when creating through EC2 with Terraform? - amazon-ec2

Question

I'm trying to create an EC2 instance for a TEST environment, which uses an AMI of PROD. Everything is creating correctly, but I can't add figure out how to add tags to the EBS volumes that are created along with it?
The tags work on the EC2 but don't get applied to the EBS or root volume. I tried adding a tag map on those as well but that was invalid. Any ideas?
provider "aws" {
region = "us-east-1"
}
data "aws_ami" "existing_sft_ami" {
most_recent = true
filter {
name = "name"
values = [var.prod_name]
}
owners = [
var.aws_account_id]
}
data "aws_subnet" "subnet" {
id = var.aws_subnet_id
}
resource "aws_instance" "sftp" {
ami = data.aws_ami.existing_sft_ami.id
instance_type = "t2.micro"
availability_zone = var.availability_zone
subnet_id = data.aws_subnet.subnet.id
key_name = var.ssh_key_name
vpc_security_group_ids = [var.aws_security_group_id]
root_block_device {
delete_on_termination = true
}
ebs_block_device {
device_name = "/dev/sdb"
delete_on_termination = true
}
tags = {
Name = var.name
Owner = var.owner
Created = formatdate("DD MMM YYYY hh:mm ZZZ", timestamp())
Environment = "TEST"
}
}

Answer 1

You need to use the additional volume_tags argument to tag the volumes. Also, to make your code a little more DRY, you can do this with a locals block.
locals {
tags = {
Name = var.name
Owner = var.owner
Created = formatdate("DD MMM YYYY hh:mm ZZZ", timestamp())
Environment = var.environment
}
}
resource "aws_instance" "sftp" {
ami = data.aws_ami.existing_sft_ami.id
instance_type = "t2.micro"
availability_zone = var.availability_zone
subnet_id = data.aws_subnet.subnet.id
key_name = var.ssh_key_name
vpc_security_group_ids = [var.aws_security_group_id]
root_block_device {
delete_on_termination = true
}
ebs_block_device {
device_name = "/dev/sdb"
delete_on_termination = true
}
tags = local.tags
volume_tags = local.tags
}

Answer 2

You can add tags attributes to root_block_device and ebs_block_device as well, that will give you more control in case you don't want to apply the same set of tags to all your block devices (which volume_tags will do).
E.g.:
provider "aws" {
region = "us-east-1"
}
data "aws_ami" "existing_sft_ami" {
most_recent = true
filter {
name = "name"
values = [var.prod_name]
}
owners = [
var.aws_account_id]
}
data "aws_subnet" "subnet" {
id = var.aws_subnet_id
}
resource "aws_instance" "sftp" {
ami = data.aws_ami.existing_sft_ami.id
instance_type = "t2.micro"
availability_zone = var.availability_zone
subnet_id = data.aws_subnet.subnet.id
key_name = var.ssh_key_name
vpc_security_group_ids = [var.aws_security_group_id]
root_block_device {
delete_on_termination = true
tags = {
Name = "${var.name}-root-volume"
Owner = var.owner
Created = formatdate("DD MMM YYYY hh:mm ZZZ", timestamp())
Environment = "TEST"
}
}
ebs_block_device {
device_name = "/dev/sdb"
delete_on_termination = true
tags = {
Name = "${var.name}-secondary-volume"
Owner = var.owner
Created = formatdate("DD MMM YYYY hh:mm ZZZ", timestamp())
Environment = "TEST"
}
}
tags = {
Name = var.name
Owner = var.owner
Created = formatdate("DD MMM YYYY hh:mm ZZZ", timestamp())
Environment = "TEST"
}
}
Like #ben-whaley said, you can avoid some repetition by defining the common set of tags as a local variable - you can combine these with tags specific to your block device using merge, as follows:
tags = merge(local.tags, {
Name = "${var.name}-secondary-volume"
})
Note that there's a bug in the AWS provider for Terraform that makes it impossible to update tags on any ebs_block_device once the instance has been created -- updating tags on the root_block_device works fine.