Description
Problem statement
#2214 introduced (through #2783) generic funcs for Event, Predicate and Handler.
TypedBuilder has only 1 type parameter for the request type and since Go (as of 1.23) doesn't allow type parameters on methods golang/go#49085, Watches() uses handler.TypedEventHandler[client.Object, request] as eventHandler parameter.
That client.Object limits the handler functions to only have client.Object as argument types so users have to use:
podForService := func(ctx context.Context, obj client.Object) []reconcile.Request {
svc , ok := obj.(*core.Service)
if !ok {
return nil
}
return nil
}
mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{})
b := ctrl.NewControllerManagedBy(mgr)
b.For(&corev1.Pod{})
b.Watches(
&corev1.Service{},
handler.TypedEnqueueRequestsFromMapFunc(
podForService,
),
)
and cannot use strongly typed handlers like
podForServiceTyped := func(ctx context.Context, svc *corev1.Service) []reconcile.Request {
return nil
}
mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{})
b := ctrl.NewControllerManagedBy(mgr)
b.For(&corev1.Pod{})
b.Watches(
&corev1.Service{},
handler.TypedEnqueueRequestsFromMapFunc(
podForServiceTyped,
),
)
because
cannot use handler.TypedEnqueueRequestsFromMapFunc(podForServiceTyped) (value of type handler.TypedEventHandler[*"k8s.io/api/core/v1".Service, reconcile.Request]) as handler.TypedEventHandler[client.Object, reconcile.Request] value in argument to b.Watches: handler.TypedEventHandler[*"k8s.io/api/core/v1".Service, reconcile.Request] does not implement handler.TypedEventHandler[client.Object, reconcile.Request] (wrong type for method Create)
have Create(context.Context, event.TypedCreateEvent[*"k8s.io/api/core/v1".Service], workqueue.TypedRateLimitingInterface[reconcile.Request])
want Create(context.Context, event.TypedCreateEvent[client.Object], workqueue.TypedRateLimitingInterface[reconcile.Request])
Additional information
Due to golang/go#49085 this cannot be (easily?at all?) implemented as noted in #2783.
This issue is mostly for tracking and to acknowledge the API limitation.
Feel free to comment on the issue if you feel there's a way to move forward without Go implementing golang/go#49085.
Current workaround
If I understand correctly, the following is an equivalent which can be used:
src := source.Kind(
mgr.GetCache(),
&corev1.Service{},
handler.TypedEnqueueRequestsFromMapFunc(
podForServiceTyped,
),
)
b.WatchesRawSource(src)