Quite a lot of unit tests set up informers with a fake client, do
informerFactory.WaitForCacheSync, then create or modify objects. Such tests
suffered from a race: because the fake client only delivered objects to the
watch after the watch has been created, creating an object too early caused
that object to not get delivered to the informer.
Usually the timing worked out okay because WaitForCacheSync typically slept a
bit while polling, giving the Watch call time to complete, but this race has
also gone wrong occasionally. Now with WaitForCacheSync returning more promptly
without polling (work in progress), the race goes wrong more often.
Instead of working around this in unit tests it's better to improve the fake
client such that List+Watch works reliably, regardless of the timing. The fake
client has traditionally not touched ResourceVersion in stored objects and
doing so now might break unit tests, so the added support for ResourceVersion
is intentionally limited to List+Watch.
The test simulates "real" usage of informers. It runs in a synctest bubble and
completes quickly:
go test -v .
=== RUN TestListAndWatch
listandwatch_test.go:67: I0101 01:00:00.000000] Listed configMaps="&ConfigMapList{ListMeta:{ 1 <nil>},Items:[]ConfigMap{ConfigMap{ObjectMeta:{cm1 default 0 0001-01-01 00:00:00 +0000 UTC <nil> <nil> map[] map[] [] [] []},Data:map[string]string{},BinaryData:map[string][]byte{},Immutable:nil,},},}" err=null
listandwatch_test.go:79: I0101 01:00:00.000000] Delaying Watch...
listandwatch_test.go:90: I0101 01:00:00.100000] Caches synced
listandwatch_test.go:107: I0101 01:00:00.100000] Created second ConfigMap
listandwatch_test.go:81: I0101 01:00:00.100000] Continuing Watch...
--- PASS: TestListAndWatch (0.00s)
PASS
ok k8s.io/client-go/testing/internal 0.009s
Some users of the fake client need to be updated to avoid test failures:
- ListMeta comparisons have to be updated.
- Optional: pass ListOptions into tracker.Watch. It's optional because
the implementation behaves as before when options are missing,
but the List+Watch race fix only works when options are passed.
Kubernetes-commit: 56448506075c3db1d16b5bbf0c581b833a4646f1
The "// import <path>" comment has been superseded by Go modules.
We don't have to remove them, but doing so has some advantages:
- They are used inconsistently, which is confusing.
- We can then also remove the (currently broken) hack/update-vanity-imports.sh.
- Last but not least, it would be a first step towards avoiding the k8s.io domain.
This commit was generated with
sed -i -e 's;^package \(.*\) // import.*;package \1;' $(git grep -l '^package.*// import' | grep -v 'vendor/')
Everything was included, except for
package labels // import k8s.io/kubernetes/pkg/util/labels
because that package is marked as "read-only".
Kubernetes-commit: 8a908e0c0bd96a3455edf7e3b5f5af90564e65b0
Note that the fake client isn't designed to work with informer. It
doesn't support resource version. It's encouraged to use a real client
in an integration/E2E test if you need to test complex behavior with
informer/controllers.
Kubernetes-commit: 942bc9b32e39bb9c6ca045c02b48cc84dfa86633
The fakeclient package does not have any non-test go files. This
causes `go build` to give a warning: `no non-test Go files in ...`.
This also causes the publishing bot to fail.
This PR adds a dummy doc.go file in the package to avoid this warning.
Kubernetes-commit: 764ae69671428987d77898b2d3c48c6c003e2fd4
This adds an example showing the steps needed to get a working
SharedInformerFactory with a fake client for testing.
Kubernetes-commit: aed487b42d1b49df9ac01f7234896f6d1b4da166
