Elastic File System (EFS) Module

Deploy an AWS Elastic File System for shared storage across EC2 instances and ECS tasks.

What You'll Build

• EFS with regional high availability
• Mount targets across availability zones
• Access points for POSIX access control
• Backup and lifecycle policies
• Performance mode and throughput settings

How to Use

module "efs" {
  source = "github.com/nnthanh101/terraform-aws/modules/efs"

  name            = "app-shared-storage"
  performance_mode = "generalPurpose"
  throughput_mode  = "bursting"
  encrypted        = true
  kms_key_id       = aws_kms_key.efs.arn

  mount_targets = {
    az1 = {
      subnet_id       = var.subnet_ids[0]
      security_groups = [aws_security_group.efs.id]
    }
    az2 = {
      subnet_id       = var.subnet_ids[1]
      security_groups = [aws_security_group.efs.id]
    }
  }

  access_points = {
    app = {
      path = "/app"
      posix_user = {
        uid = 1000
        gid = 1000
      }
      root_directory = {
        path = "/app"
        creation_info = {
          owner_uid   = 1000
          owner_gid   = 1000
          permissions = "755"
        }
      }
    }
  }

  tags = {
    Environment = "prod"
    Service     = "shared-storage"
  }
}

Key Variables

Variable	Type	Purpose
name	string	EFS file system name
performance_mode	string	"generalPurpose" or "maxIO"
throughput_mode	string	"bursting" or "provisioned"
encrypted	bool	Enable encryption at rest
kms_key_id	string	KMS key ARN for encryption
mount_targets	map(object)	AZ-specific mount target configs
access_points	map(object)	POSIX-compliant application access
lifecycle_policy	object	Transition to infrequent access (IA)

Outputs

Output	Use Case
id	EFS file system ID for mount commands
arn	ARN for IAM policy references
dns_name	Domain name for NFS mounting
mount_targets	Mount target details per AZ
access_points	Access point IDs for ECS task volumes

Integration

• EC2: Mount via nfs4 mount -t nfs4 -o nfsvers=4.1 ${dns_name}:/ /mnt/efs
• ECS: Use access points in task definition volumes
• KMS: Encrypt data at rest with customer-managed key
• Backup: Enable AWS Backup for disaster recovery
• Security Groups: Control network access to mount targets

Source Reference

Module: terraform-aws/modules/efs