Thanks for this pull request. I'm not familiar with kustomize. I'm going to read up on that before reviewing.

Please add the kustomization.yaml to this project since it would greatly simplify the installation of this project using Kustomize.
At my customer, all K8S service are always deployed via Kustomize since our infra always needs some addition custom configuration like NetworkPolicies, etc. With Kustomize, we can refer to the project's own deployment config (Helm Chart, Kustomize yaml or separate yaml's) and customise those for our environment.
Since origin-ca-issuer uses multiple yaml config's we now have to reference those ourselves and this would break of the project changes these filenames or adds or removes files.
By providing a kustomation.yaml we could just reference that file and automatically get any changes to the yaml configs.

Hi, is this PR going to be merged anytime soon ? I am trying to use kustomize to clone the deploy folder which will make it much easier if we have this feature added.

Hello. I'll be revisiting this soon.

Hello. We need this too. Thanks!
I believe this has no side effects. So we can merge this.

Would also love to see this merged!

You can test this already by using kustomize built into kubectl:

kubectl kustomize deploy/

I'd however also add a kustomization at the root of the repo so users can install it by doing
kubectl kustomize https://github.com/cloudflare/origin-ca-issuer

To see how this is done you can view: https://github.com/ricoberger/vault-secrets-operator or https://github.com/prometheus-operator/prometheus-operator/blob/main/kustomization.yaml