Description
Problems
In my case, my deployment manifests have both cluster scoped resources (e.g. CustomResourceDefinition, ClusterRoleBinding) and namespace scoped resources(e.g. Deployment, Service). I want to assign a namespace value to the namespace scoped resources. I also want the declarativeObject to be the ownerRef of both kinds, so that I can have the deployment manifests be easily cleaned up by just deleting the declarativeObject.
Available features
Current k-d-p provides 3 handy features:
- Users do not need to assign namespaces to their deployment manifests, as long as the
declarativeObjectis namespace scoped, its value can be used to modify any namespace scoped deployment manifests which does not have the namespace assigned. - Users can choose to disable this namespace auto-assign feature by
WithPreserveNamespace. - Users can request the
declarativeObjectto be the owner of the deployment manifests, which is very easy for resource clean up. This can be done viadeclarative.WithOwner(declarative.SourceAsOwner). If thedeclarativeObjectis namespace scoped, the cluster scoped deployment manifests will be skipped and won't have a ownerRef. thedeclarativeObjectis cluster scoped, all manifests will have it as theownerRef.
My current solutions
Right now, I have two options but neither are handy enough:
Option 1:
Set the declarativeObject as namespace scoped, this will auto-assign the namespace to deployment manifests. It has two problems:
- I have to create the namespace object before applying the
declarativeObjectobject and cannot rely on my k-d-p operator to guarantee the existence of the namespace. - I have to manage the cluster scoped resources separately, because namespace scoped resource can not be the
ownerRefif cluster resources.
Option 2:
The declarativeObject is cluster scoped. It can be the ownerRef of all manifests and I can add the namespace existence logic in my k-d-p operator. But I have to implement my own declarative methods to update the namespace.
Proposals
Add a new declarative method which does not rely on the declarativeObject but can assign given namespace to the deployment manifests (it's different than skipping the namespace as what WithPreserveNamespace does, but assigning default namespace). Even better, if the namespace object does not exist in the cluster, I want it to be created by request.
New declarative method
WithNamespace(namespace string, createIfNotExist bool)
This method assigns namespace namespace to any namespace scoped deployment manifests, only if their current namespace is empty (basically the same behavior of current setNamespaces but using a dedicated namespace value).
namespace is the dedicated namespace value,
createIfNotExist guarantees the existence of the namespace object before applying any other resources.
Please share your thoughts!
I think the use case I described can be very common for users who need k-d-p. And I'm just proposing a simple solution that is good enough for my use case. I think the behavior of WithNamespace can also be extended to update all the namespace-scoped deployment manifests rather than merely the unassigned ones. But I don't have a strong opinion on this.
Besides updating the metadata.namespace, we can also extend the setNamespace to update spec/conversion/webhook/clientConfig/service/namespace in CustomResourceDefinition, spec/service/namespace in APIService, etc.