This adds a ToUnstructured method to complement the FromUnstructured method
we have had for some time. The ToUnstructured method is effectively scoped
to Knative-style types since we expect it to implement both kmeta.Accessor
and kmeta.OwnerRefable in order to ensure that the TypeMeta is always
properly populated.
This starts to sketch common libraries for instantiating informers/listers for a particular GroupVersionResource as one of our duck types.
You can instantiate a duck.InformerFactory like so:
```go
dynaClient, err := dynamic.NewForConfig(cfg)
if err != nil {
logger.Fatalf("Error building dynamic clientset: %v", err)
}
// Cache as the outermost layer so we only register the EventHandler once.
dif := &duck.CachedInformerFactory{
Delegate: &duck.EnqueueInformerFactory{
Delegate: &duck.TypedInformerFactory{
Client: dynaClient,
Type: &duckv1alpha1.Target{},
ResyncPeriod: 30 * time.Second,
StopChannel: stopCh,
},
EventHandler: cache.ResourceEventHandlerFuncs{
AddFunc: func(obj interface{}) {
// Enqueue, obj is: *duckerv1alpha1.Target
},
UpdateFunc: func(old, new interface{}) {
// Enqueue, old and new are: *duckerv1alpha1.Target
},
},
},
}
```
Then, as you come across new GroupVersionResources that you want to handle:
```go
informer, lister, err := dif.Get(gvr)
if err != nil {
logger.Fatalf("Error starting shared index informer: %v", err)
}
```
With the `duck.TypedInformerFactory` the objects will be returned as the provided `Type:`, so in this example, you could safely write:
```go
elt, err := lister.ByNamespace(ns).Get(name)
if err != nil { ... }
target := elt.(*duckv1alpha1.Target)
// Stuff involving target.
```
* first cut of defining Subscribable and Channelable
* address pr feedback
* remove now unnecessary From*Unstructured conversions
* address pr comments, add util_test
* Introduce LegacyTarget and make Target more structured
* add extra level of structure in Sinkable
* move util* to duck/util, change Sinkable string to SinkableDomain as per pr comments
* add callableDomain
* oops
* address PR feedback
* clarify comments
* Move util to pkg/duck
* Normalize the names of Status structs.
Dave Protasowski
Markus Thömmes
Victor Agababov
Matt Moore
Matt Moore
Ville Aikas