operator-sdk VS terraform-provider-kubernetes-alpha

Now I’d like to call out the Operator Framework here, and more specifically the Operator SDK and the individual operators that make up a number of the things we’ve covered here.

So the metric port is already used.The Operator SDK generates ports for metrics and health automatically. These are set in the main.go

It does not solve the organizational problem as others indicated, but a useful tool to resolve inter-service dependencies might be the https://sdk.operatorframework.io/ for Kubernetes. You could make the operator check if certain conditions are met, e.g. if a certain service is available or provides a certain feature before letting it deploy the real workload. The idea is to basically encode the human operator know how into code and let the operator itself be a stateless deployment which you can simply push, e.g. via GitOps tooling like ArgoCD or Flux. You not only can encode deployment related parts, but also day two operations tasks, like backup/restore or failover scenarios.

There are client libraries for other common languages but if you us Go you can import the native Kubernetes code into your project which is significantly easier. In particular, Operator SDK makes writing Operators much easier and only supports Go.

Maybe that's the point. I am thinking of people who might (mistakenly) assume that they need to maintain multiple Go version on their machines because the project's readme "requires" a particular version. (Example: operator-sdk says "releases are compiled with Go 1.16". Looking deeper into the project, I see the Go version hard-coded into GitHub Action configs, but I see no explanation why the code cannot be compiled with Go 1.17.x instead.)

If I want to launch a k8 operator into my cluster, is there any way to do it through the K8 provider? Or will I have to do some messy null_resource local-exec kubectl apply steps myself?

A controller can be written in any language. We’ll use Golang as Kubernetes’ "native" language. We could write a controller’s logic from scratch but the good folks from Google and RedHat gave us a leg up. They have created two projects that can generate the operator code that will only require minimum changes – kubebuilder and operator-sdk. These two are compared at the kubebuilder vs operator-sdk page, as well as here: What is the difference between kubebuilder and operator-sdk #1758.

Open since March with no progress on that issue but I just noticed 0.4 adds a fallback for OpenAPI validation failure ... so need to test if this is fixed (after almost 2 months) - https://github.com/hashicorp/terraform-provider-kubernetes-alpha/issues/181#issuecomment-852037406

GitHub repository

You can use the new Kubernetes alpha provider to apply any YAML manifest against your cluster. It’s very new and still in Alpha or Beta but it solves this exact problem. Check it out: https://github.com/hashicorp/terraform-provider-kubernetes-alpha