• Contents:

DEMO: Implementing a Basic EFS

Ref: https://learn.cantrill.io/courses/1820301/lectures/41301665 and https://learn.cantrill.io/courses/1820301/lectures/41301666

• 💡 In this demo, we create an EFS file system that is deployed in a custom VPC
  • Use the same EFS settings as in the video
• 🔧 It is best practice to put a mount target in every AZ where a resource will consume EFS
• Every mount target needs an attached SG - Screenshot:

Configuring an EC2 Instance to Use EFS

• 💡 We run these commands inside an EC2 instance

1. df -k — List all mounted FSs in the Linux OS (we can see there is no EFS file system yet)
   • ”disk free” → displays the available disk space in each of the partitions in the system
   • -k → show available space in kB
2. sudo mkdir -p /efs/wp-content — Make a directory with specified path and name
   • -p → the specified path will be created if it doesn't already exist
3. sudo dnf -y install amazon-efs-utils — Install a package of tools to interact with EFS
   • -y → acknowledges (”yes”) all prompts
4. sudo nano /etc/fstab — Open FSTAB file to edit it
   • 🔧 FSTAB file contains info of all FSs that will be mounted when the instance (re)boots
   • Add this line at EOF: <file-system-id>:/ /efs/wp-content efs _netdev,tls,iam 0 0
     • ❗ Substitute <file-system-id> with the ID of the FS in EFS!
5. sudo mount /efs/wp-content — Mount the specified directory according to the FSTAB file configuration
6. df -k — We can now see that the EFS file system is mounted in the instance

• 💡 Now that the system is mounted, we can navigate to /efs/wp-content and e.g. add a file
  • That file is in the EFS file system
  • If we configure a different EC2 instance in the VPC to access the same EFS file system, we will be able to access the same file → shared NW file system

WordPress Architecture with EFS

Ref: https://learn.cantrill.io/courses/1820301/lectures/41301667

• A new step of moving the architecture from a monolith to being fully elastic and resilient
  • Local FS is no longer critical, it no longer stores WordPress media uploaded to posts
  • Both instances access the same content/data, which is stored in RDS and in EFS
  • We can scale horizontally (up or down) according to system load, increasing or decreasing the number of EC2 instances. There can be 1, 2, or 200 instances.