anthonygclark / eks-terraform

Provision EKS clusters with terraform

This is derived from Learn Terraform Provisioner - EKS Cluster and its companion tutorial. Significant modifications were made to allow configuration dependencies to be generated by Terraform directly.

Objectives:

• Provision full-featured Kubernetes clusters on AWS with sensible defaults
• Minimize infrastructure costs

Notable defaults:

• Fully encrypted disks & secrets in cluster
• Spot instances and autoscaling

Notable options for configuration:

• Autoscaling can be disabled
• NAT gateway usage can be disabled

Tested upgrade path from Kubernetes 1.20 to 1.21. Upgrades are slow, mainly due to unobservable control plane processes in EKS.

Usage

Configure your cluster details in terraform.tfvars.json.

Create the cluster:

bash -x up.sh

When you reconfigure your cluster, either by modifying Terraform files or the variables:

bash -x up.sh

NB: because the autoscaler will modify the desired size of each autoscaling group, Terraform will report changes having been made outside of Terraform's operations. This is normal, and shouldn't impact application operations.

Destroy the cluster:

bash -x down.sh

Future improvements

• A nice CLI wrapper, perhaps
• A pre-generated admin service account for attaching other management apps
• Smarter automation of security groups
• Cleaner configuration of node groups (right now it seems really disjoint to me)
• Validate the behavior of running applications (e.g. a database) during upgrade