Align node filtering with service controller

[octplane]

Hello,

Would there be any interest in aligning the current node selection currently done when building the Instances Group:

https://github.com/kubernetes/ingress-gce/blob/master/pkg/controller/utils.go#L202-L215

• code ignores Unschedulable nodes,

to the one in k8s:

https://github.com/kubernetes/kubernetes/blob/97fdf8ac70dfdaf07074dee6b6cb345be71e96ec/pkg/controller/service/service_controller.go#L585-L619

code ignores:

• Unschedulable nodes
• Nodes with the label node-role.kubernetes.io/master
• Nodes with the label alpha.service-controller.kubernetes.io/exclude-balancer

More generally, it might be nice to allow to blacklist labels via configuration.

[rramkumar1]

Fixed by #370
/close