How to automate root device volume tags using CloudFormation

Question

I can’t tag the volume of the root device attached to EC2 using CloudFormation to display blocking devices because the tags do not apply to Amazon EBS volumes created from device block mappings . Can the tagging root device volume be automated using CloudFormation in any way? Thanks.

Answer 1

This can be done using UserData - if you are using a linux host with cloudinit and awscli installed , you can run the following in the UserData script to mark all volumes associated with the instance

"VOLUME_IDS=$(aws ec2 describe-volumes --output text --filters Name=attachment.instance-id,Values=$(curl http://169.254.169.254/latest/meta-data/instance-id) --query 'Volumes[].VolumeId')",
"aws ec2 create-tags --resources ${VOLUME_IDS} --tags Key=my,Value=tag"

• retrieves the current instance id
• uses instance id as a filter to describe volumes
• jmespath query returns only volume identifiers
• volume identifiers passed to create tags with / s tags that you want to add

make sure that when you start your EC2 instance, it has an IAM instance policy that allows you to create tags and describe volumes

"PolicyDocument": {
    "Version": "2012-10-17",
    "Statement": [
        {
            "Action": [
                "ec2:CreateTags",
                "ec2:DescribeVolumes"
            ],
            "Effect": "Allow",
            "Resource": "*"
        }
    ]
}