Add Status to kubeless CRD objects

[murali-reddy]

We should add resource status to the function object, and any other CRD's kubeless may have (e.g. runtime, trigger etc)

to start with function object should have Status along with Spec something like below:

// Function object
type Function struct {
	metav1.TypeMeta `json:",inline"`
	Metadata               metav1.ObjectMeta `json:"metadata"`
	Spec   FunctionSpec `json:"spec"`
        Status FunctionStatus `json:"status,omitempty"`
}

Things like function status, http endpoint etc should go in the FunctionStatus.

Current way of inferring the status of the function by kubeless client should go away into controller. Client should just reflect the status of the function returned by API.

[andresmgot]

does this require a watcher in the controller?

[murali-reddy]

Kubeless controller is/will be the source of change to function objects (or any other CRD api objects that may come), so dont see need for it.

[andresmgot]

what if the deployment crashes? or should the controller wait until the deployment is ready?

[sayanh]

@andresmgot @murali-reddy Do we still consider solving this? As of now, I do see status: {} subresource but there is no feedback from kubeless-controller.

[murali-reddy]

Support for Status in CRD only got in 1.10 and will be beta in 1.11

kubernetes/enhancements#571

When Kubeless moves to latest client-go and supports 1.10/1.11 we can add support for status.