This makes the API nicer:
resourceClaims:
- name: with-template
resourceClaimTemplateName: test-inline-claim-template
- name: with-claim
resourceClaimName: test-shared-claim
Previously, this was:
resourceClaims:
- name: with-template
source:
resourceClaimTemplateName: test-inline-claim-template
- name: with-claim
source:
resourceClaimName: test-shared-claim
A more long-term benefit is that other, future alternatives
might not make sense under the "source" umbrella.
This is a breaking change. It's justified because DRA is still
alpha and will have several other API breaks in 1.31.
The JSON patch approach works, but it is complex. A retry loop is easier to
understand (detect conflict, get new claim, try again). There is one additional
API call (the get), but in practice this scenario is unlikely.
There was a race caused by having to update claim finalizer and status in two
different operations:
- Resource claim controller removes allocation, does not yet
get to remove the finalizer.
- Scheduler prepares an allocation, without adding the finalizer
because it's there.
- Controller removes finalizer.
- Scheduler adds allocation.
This is an invalid state. Automatic checking found this during the execution of
the "with translated parameters on single node.*supports sharing a claim
sequentially" E2E test, but only when run stand-alone. When running in
parallel (as in the CI), the bad outcome of the race did not occur.
The fix is to check that the finalizer is still set when adding the
allocation. The apiserver doesn't check that because it doesn't know which
finalizer goes with the allocation result. It could check for "some finalizer",
but that is not guaranteed to be correct (could be some unrelated one).
Checking the finalizer can only be done with a JSON patch. Despite the
complications, having the ability to add multiple pods concurrently to
ReservedFor seems worth it (avoids expensive rescheduling or a local retry
loop).
The resource claim controller doesn't need this, it can do a normal update
which implicitly checks ResourceVersion.
The DRA plugin does that. It didn't actually work and only printed an error
message about NodeInfo not implementing klog.KMetata. That's not a compile-time
check due to limitations with Go generics and had been missed earlier.
This finishes the transition to the assume cache as source of truth for the
current set of claims.
The tests have to be adapted. It's not enough anymore to directly put objects
into the informer store because that doesn't change the assume cache
content. Instead, normal Create/Update calls and waiting for the cache update
are needed.
This enables connecting the event handler for ResourceClaim to the assume
cache, which addresses a theoretic race condition.
It may also be useful for implementing the autoscaler support, because now
the autoscaler can modify the content of the cache.
The claim parameter key didn't include the namespace of the claim. In the case
where two namespaces used the exact same parameter reference, the "too many
generated parameters" case got triggered incorrectly and lookup could have
returned an object from the wrong namespace.
Found while running the E2E tests in parallel:
message: 'running PreFilter plugin "DynamicResources": multiple generated claim
parameters for ConfigMap. dra-8794/parameters-3 found: [dra-4729/parameters-4
dra-7328/parameters-4 dra-8794/parameters-4 dra-3402/parameters-4 dra-6156/parameters-4
dra-1839/parameters-4 dra-7434/parameters-4 dra-6504/parameters-4]'
Any error result from PreBind was treated as a pod scheduling failure. This was
overlooked when moving blocking API calls in the DRA plugin into a PreBind
implementation, leading to:
E0604 15:45:50.980929 306340 schedule_one.go:1048] "Error scheduling pod; retrying" err="waiting for resource driver" pod="test/test-draqld28"
That's because DRA's PreBind does some updates in the apiserver, then returns
Pending to wait for the outcome.
The fix is to allow PreBind to return the same special status codes as other
extension points.
There's no reason for having the interface because there is only one
implementation. Makes the implementation of the test functions a bit
simpler (no casting). They are still stand-alone functions instead of methods
because they should not be considered part of the "normal" API.
This is now used by both the volumebinding and dynamicresources plugin, so
promoting it to a common helper package is better.
In terms of functionality, nothing was changed. Documentation got
updated (warns about storing locally modified objects, clarifies what the Get
parameters are). Code coverage should be a bit better than before (tested with
and without indexer, exercises event handlers, more error paths).
Checking for specific errors can now be done via errors.Is.
Clearing some irrelevant fields in objects caused a flaky data race alert
because in some cases, the objects were pointers into a shared cache. A better
solution is to treat the objects as read-only and ignore the irrelevant fields.
