Invalidate API resources cache

[jacobtomlinson]

In #254 I added a cache for API resources to mimic the behaviour of kubectl. However it looks like kubectl invalidates the cache if you request a resource not contained in the cache and tries again.

Reproducible steps:

• Call kr8s.get("po") # Populates the cache and lists pods
• Create a new CRD with the short name foo and a kr8s class for it
• Call kr8s.get("foo") # Will not find it because "foo" is not in the cache

When we fail to look up foo we need to invalidate the cache and try again.

[benedikt-bartscher]

I noticed this kubectl behaviour aswell. If i apply a new CRD kubectls auto-completion only works after some minutes or if i interact with those crds for example with kubectl get. Maybe we also want to invalidate the cache if kr8s executes any of the CRUD actions on crds itself.

Edit: iirc kubectl does not do this. If you create a new CRD with kubectl, the cache does not get invalidated. Its your choice if kr8s should be a little "smarter" or tied to the kubectl design.

[jacobtomlinson]

Oh interesting, when I was poking around the kubectl source I felt like it was retrying if the resource name was not found in the cache, but maybe not!

[marceloFA]

Can I work with this one? If yes, here's a question about this issue:

| When we fail to look up foo we need to invalidate the cache and try again.

Is there any way to differentiate a look-up failure due to a new CRD instead of a resource that actually does not exist? I think the latter is what happens the most and it would be a bit of time and network resource waste to look-up again something that actually does not exist

[jacobtomlinson]

Sure that would be great.

The way the Go client implements this is to have a function that looks up a resource. Then within that function, it first tries to look that up in the cache only, if it isn't found then it invalidates the cache and tries again.

We might want to go down the same road of encapsulating the lookup logic into a single function where we can control the cache more directly.