Add initial support for handling NodeFeature objects. With this patch
nfd-master watches NodeFeature objects in all namespaces and reacts to
changes in any of these. The node which a certain NodeFeature object
affects is determined by the "nfd.node.kubernetes.io/node-name"
annotation of the object. When a NodeFeature object targeting certain
node is changed, nfd-master needs to process all other objects targeting
the same node, too, because there may be dependencies between them.
Add a new command line flag for selecting between gRPC and NodeFeature
CRD API as the source of feature requests. Enabling NodeFeature API
disables the gRPC interface.
-enable-nodefeature-api enable NodeFeature CRD API for incoming
feature requests, will disable the gRPC
interface (defaults to false)
It is not possible to serve gRPC and watch NodeFeature objects at the
same time. This is deliberate to avoid labeling races e.g. by nfd-worker
sending gRPC requests but NodeFeature objects in the cluster
"overriding" those changes (labels from the gRPC requests will get
overridden when NodeFeature objects are processed).