This Pritunl VPN built with Terraform is a single instance that sits behind a load balancer inside and auto-scaling group in AWS. It is built using Terraform and also includes its own VPC. Upon first creation a backup script is created using the user_data script. The backup runs as a cron hourly. It backs up all data for the vpn to an S3 bucket that is created. Should the instance ever fall over when the ASG spins up another one a recovery script is also created by the user_data. The instance finishes spinning up, installs the latest version of Pritunl and then runs the recovery script. This pulls all of your data from the S3 bucket, loads it into the Pritunl instance and bounces the Pritunl application. When it comes back on line after a few minutes all user data and configurations are still in place.
Feel free to download and use for yourself. This is a very basic setup of Pritunl and can be expanded to be much more.