added ingress-nginx kpt package

[droot]

This PR adds kpt package for ingress-nginx cluster addon.

README.md in the package documents the steps that we used to create the package.

Note: This time we are using kpt fn to transform the static manifests released by ingress-nginx project.

[droot]

/cc @yuwenma @bgrant0607 @justinsb

[justinsb]

One question, but lgtm

[yuwenma]

Looks good. I think we can also add the set-labels and set-namespace:v0.3.4 in Kptfile.

[bgrant0607]

Just some thoughts on future improvements

[bgrant0607]

We'll want to be able to use set-image to update the tag and digest.

[droot]

So, this will be an imperative operation on this package, right.

[bgrant0607]

We'll want something that can extract OS and arch info from a container image so that a function could then inject appropriate selectors.

[droot]

Good pt. Filed an issue #3386

[bgrant0607]

We'll want to explore how to make this pattern easier. 3 resources are required: the ServiceAccount, the Role, and the RoleBinding. Of those, only the Role requires user input. The UI could guide the user through the creation process and provide autocompletion, but that wouldn't address the CLI experience.

[droot]

Yes.

Actually, for the kubebuilder based controllers, kubebuilder will read the permissions for the Role from the comments (annotations) defined above the API types (or reconciler function).

[droot]

Thanks for the feedback everyone.

[droot]

Good pt. Filed an issue #3386

[droot]

Yes.

Actually, for the kubebuilder based controllers, kubebuilder will read the permissions for the Role from the comments (annotations) defined above the API types (or reconciler function).

[droot]

Looks good. I think we can also add the set-labels and set-namespace:v0.3.4 in Kptfile.

We don't need to use set-namespace for this because there will be only one add-on per cluster. Configuring anything other than the ingress-nginx namespace is going to be exception rather than norm (Note all the docs etc use the default namespace so less likely someone will do it), so will add functions for the most common customizations.

Regarding set-labels, yes, this can be done. I will add it in the next iteration. I will have to use function target selector to selectively apply labels because multiple components are involved so want to play with it first.