[Question] How to make some changes to a generated reconclier

[djdongjin]

Hi, I have a question about reconcilers built based on kubebuild-declarative-pattern. Suppose I want that in the reconcile loop, the reconciler should read an annotation from a namespace and based on that annotation value, add a node-affinity (or any other deployment change) to the deployment it creates. Is it possible? Thanks! For example:

1. Reconclier: https://github.com/kubernetes-sigs/kubebuilder-declarative-pattern/blob/master/examples/guestbook-operator/controllers/guestbook_controller.go#L55
2. Deployment: https://github.com/kubernetes-sigs/kubebuilder-declarative-pattern/blob/master/examples/guestbook-operator/channels/packages/guestbook/0.1.0/manifest.yaml#L19

Basically, the question is how to make some customization to the generated reconclier.

[atoato88]

I think we can do that operation by multiple options.

• option 1: patch manifest by kustomize guestbook-operator is set with WithApplyKustomize at here. So you can patch target manifest by the way kustomize can. I created sample codebase which add kustomize patch, please refer this. I think it's easier way than next one.

• option 2: implement a func for used by WithObjectTransform We can implement any functions for manipulating a target manifest in Go code. It's more flexible way than previous one, because this way can implement any logics as you like. But it's more complicated, I think.

I'm not sure that which one is better for your requirement, but maybe option 2 is better because your requirement seems to have some logics depending on complicated condtion.

[djdongjin]

@atoato88 thanks for the suggestion! I finally figured it out using the WithObjectTransform and MutatePodSpec here

[atoato88]

You're welcome, and thank you for sharing your solution. 😉