attached_ebs

attached_ebs

Introduction

attached_ebs is a Terraform module used to generate persistent EBS or EC2 Instance Store volumes and attach them to auto-scaled instances, also managing daily snapshots for EBS instances.

Usage

Set the input variable group to a unique identifier to use to refer to the group of disks. Make sure to tag all of your instances with Group=XXXX (with XXXX as the value you set for group). This is used by the IAM policy to enable permissions for attaching EBS volumes within the group.

The input variable attached_ebs takes a map of volume definitions to attach to instances on boot:

module "attached-ebs" {
  source = "github.com/ondat/etcd3-bootstrap/terraform/modules/attached_ebs"
  attached_ebs = {
    "ondat_data_1": { # Basic EBS example
      size = 100
      availability_zone = eu-west-1a
      encrypted = true
      volume_type = gp3
      block_device_aws = "/dev/xvda1"
      block_device_os = "/dev/nvme0n1"
      block_device_mount_path = "/var/lib/data0"
    }
    "ondat_data_2": { # EC2 Instance Store
      availability_zone = eu-west-1a
      ephemeral = true
      block_device_os = "/dev/nvme1n1"
      block_device_mount_path = "/var/lib/data0"
    }
    "ondat_data_3": { # Full EBS example
      size = 100
      availability_zone = eu-west-1a
      dependson = ["ondat_data_1"]
      encrypted = true
      restore_snapshot = ""
      iops = 3000
      volume_type = io2
      throughput = 150000
      kms_key_id = "arn:aws::kms/..."
      block_device_aws = /dev/xvda2
      block_device_os = /dev/nvme2n1
      block_device_mount_path = /var/lib/data1
    }
  }
}

For airgapped or private environments, use the variable ebs_bootstrap_binary_url to provide an HTTP/S address from which to retrieve the necessary binary.

Use the output iam_role_policy_document to generate and assign the policy to your ASG node's role.

Use the output userdata_snippets_by_az to embed in your ASG's userdata - it's a map of AZ to snippets.

Appendix

Requirements

No requirements.

Providers

Name	Version
aws	4.16.0

Modules

No modules.

Resources

Name	Type
aws_dlm_lifecycle_policy.automatic_snapshots	resource
aws_ebs_volume.ssd	resource
aws_iam_role.dlm_lifecycle_role	resource
aws_iam_role_policy.dlm_lifecycle	resource
aws_iam_policy_document.ebs	data source
aws_region.current	data source

Inputs

Name	Description	Type	Default	Required
attached_ebs	Map of the EBS objects to allocate	any	n/a	yes
ebs_bootstrap_binary_url	Custom URL from which to download the ebs_bootstrap binary	any	null	no
group	A unique identifier for the EBS group	string	n/a	yes

Outputs

Name	Description
iam_role_policy_document	IAM role policy document to assign to ASG instance role
userdata_snippets_by_az	Map of snippets of userdata to assign to ASG instances by availability zone