This is the second and final step towards making kubelet independent of the
resource.k8s.io API versioning because it now doesn't need to copy structs
defined by that API from the driver to the API server.
This is a first step towards making kubelet independent of the resource.k8s.io
API versioning because it now doesn't need to copy structs defined by that API
from the driver to the API server. The next step is removing the other
direction (reading ResourceClaim status and passing the resource handle to
drivers).
The drivers must get deployed so that they have their own connection to the API
server. Securing at least the writes via a validating admission policy should
be possible.
As before, the kubelet removes all ResourceSlices for its node at startup, then
DRA drivers recreate them if (and only if) they start up again. This ensures
that there are no orphaned ResourceSlices when a driver gets removed while the
kubelet was down.
While at it, logging gets cleaned up and updated to use structured, contextual
logging as much as possible. gRPC requests and streams now use a shared,
per-process request ID and streams also get logged.
The information is received from the DRA driver plugin through a new gRPC
streaming interface. This is backwards compatible with old DRA driver kubelet
plugins, their gRPC server will return "not implemented" and that can be
handled by kubelet. Therefore no API break is needed.
However, DRA drivers need to be updated because the Go API changed. They can
return
status.New(codes.Unimplemented, "no node resource support").Err()
if they don't support the new ListAndWatchResources method and
structured parameters.
The controller in kubelet then synchronizes this information from the driver
with NodeResourceSlice objects, creating, updating and deleting them as needed.
