A few months back I saw that HashiCorp had released a new Kubernetes (K8s) Provider for Terraform, currently in Alpha state, which enable users to deploy K8s resources using the popular Infrastructure-as-Code (IaC) tool. I thought this would be pretty cool if it works with our vSphere with Tanzu solution, since the Tanzu Kubernetes Grid (TKG) Service uses ClusterAPI via a custom VM Operator to deploy TKG Guest Clusters which is just a fancy way of saying it uses K8s API to deploy more K8s 🙂
UPDATE (04/27/21) – vSphere 7.0 Update 2a has resolved the admission webhook issue and users can now deploy TKG Guest Cluster using K8s Provider for Terraform
The setting up the new K8s provider was pretty straight forward and after spending a few minutes in figuring out how to convert my existing TKG YAML to the required HCL format for Terraform to understand, I was able to to run a terraform "plan" but quickly ran into the following error:
failed: admission webhook "default.mutating.tanzukubernetescluster.run.tanzu.vmware.com" does not support dry run
It looks like our tanzukubernetescluster admission webhooks does not currently support dry run operations which can be quite useful but also common when using Terraform. I figured this was the end of that idea and I ended up just filing a feature enhancement internally for adding this support in the future as I can see this being quite useful for our customers.
After finishing up recent pet project of getting a fully functional vSphere with Tanzu on a homelab budget and just using 32GB of memory, I decided to take another look at this and discovered the required tweak to get this working was super trivial, literally a single line change.
Disclaimer: This is not officially supported by VMware, use at your own risk.