With the ClientsAllowCBOR client-go feature gate enabled, a 415 response to a CBOR-encoded REST
causes all subsequent requests from the client to fall back to a JSON request encoding. This
mechanism had only worked as intended when CBOR was explicitly configured in the
ClientContentConfig. When both ClientsAllowCBOR and ClientsPreferCBOR are enabled, an
unconfigured (empty) content type defaults to CBOR instead of JSON. Both ways of configuring a
client to use the CBOR request encoding are now subject to the same fallback mechanism.
This fixes an issue in
TestSchedulerPerf/SteadyStateClusterResourceClaimTemplate:
scheduler_perf.go:1542: FATAL ERROR: op 7: delete scheduled pods: client rate limiter Wait returned an error: rate: Wait(n=1) would exceed context deadline
That occurs when the test is almost done, but hasn't observed all scheduled
pods yet. The previous attempt to address this error wasn't actually 100%
correct. It covered the case when the context has already been canceled, but
not this particular "will reach deadline soon".
Integration testing has to this point relied on patching serving codecs for built-in APIs. The
test-only patching is removed and replaced by feature gated checks at runtime.
The media type application/cbor describes exactly one encoded item. As a new (to Kubernetes) format
with no existing clients, streaming/watch responses will use the application/cbor-seq media
type. CBOR watch responses conform to the specification of CBOR Sequences and are encoded as the
concatenation of zero or more items with no additional framing.
This is meant to make it easier to remove the v1alpha3 because it won't be used
in clusters that started with DRA as beta in Kubernetes 1.32 when all clients
support v1beta1.
Setting AllAlpha=true in integration tests changes the dynamic client request encoding and the
custom resource storage encoding to CBOR. The etcd storage path is updated to accept either JSON or
CBOR as storage encoding. The client feature gate controlling the dynamic client request encoding is
temporarily disabled until the serving codecs for builtin APIs are wired to the CBOR apiserver
feature gate.
For alpha, there is one apiserver feature gate and two client-go feature gates controlling
CBOR. They were initially wired to separate test-only feature gate instances in order to prevent
them from being configurable at runtime via command-line flags or environment variables (for
client-go feature gates outside of Kubernetes components). All of the integration tests required by
the KEP as alpha criteria have been implemented. This adds the feature gates to the usual feature
gate instances and removes the temporary code to support separate test-only feature gate instances.
