fdcbb6cba9
The main advantage is that waiting on channels creates a causal relationship
between goroutines which is visible to synctest. When a controller in a
synctest bubble does a WaitFor in a test's background goroutine for the
controller, the test can use synctest.Wait to wait for completion of cache
sync, without requiring any test specific "has controller synced" API. Without
this, the test had to poll or otherwise wait for the controller.
The polling in WaitForCacheSync moved the virtual clock forward by a random
amount, depending on how often it had to check in wait.Poll. Now tests can be
written such that all events during a test happen at a predictable time. This
will be demonstrated in a separate commit for the
pkg/controller/devicetainteviction unit test.
The benefit for normal production is immediate continuation when the last
informer is synced (not really a problem, but still...) and more important,
nicer logging thanks to the names associated with the thing that is being
waited for. The caller decides whether logging is enabled or disabled and
describes what is being waited for (typically informer caches, but maybe also
event handlers or even something else entirely as long as it implements the
DoneChecker interface).
Before:
Waiting for caches to sync
Caches are synced
After:
Waiting for="cache and event handler sync"
Done waiting for="cache and event handler sync" instance="SharedIndexInformer *v1.Pod"
Done waiting for="cache and event handler sync" instance="SharedIndexInformer *v1.ResourceClaim"
Done waiting for="cache and event handler sync" instance="SharedIndexInformer *v1.ResourceSlice"
Done waiting for="cache and event handler sync" instance="SharedIndexInformer *v1.DeviceClass"
Done waiting for="cache and event handler sync" instance="SharedIndexInformer *v1alpha3.DeviceTaintRule"
Done waiting for="cache and event handler sync" instance="SharedIndexInformer *v1.ResourceClaim + event handler k8s.io/kubernetes/pkg/controller/devicetainteviction.(*Controller).Run"
Done waiting for="cache and event handler sync" instance="SharedIndexInformer *v1.Pod + event handler k8s.io/kubernetes/pkg/controller/devicetainteviction.(*Controller).Run"
Done waiting for="cache and event handler sync" instance="SharedIndexInformer *v1alpha3.DeviceTaintRule + event handler k8s.io/kubernetes/pkg/controller/devicetainteviction.(*Controller).Run"
Done waiting for="cache and event handler sync" instance="SharedIndexInformer *v1.ResourceSlice + event handler k8s.io/kubernetes/pkg/controller/devicetainteviction.(*Controller).Run"
The "SharedIndexInformer *v1.Pod" is also how this appears in metrics.
External Repository Staging Area
This directory is the staging area for packages that have been split to their own repository. The content here will be periodically published to respective top-level k8s.io repositories.
Repositories currently staged here:
k8s.io/apik8s.io/apiextensions-apiserverk8s.io/apimachineryk8s.io/apiserverk8s.io/cli-runtimek8s.io/client-gok8s.io/cloud-providerk8s.io/cluster-bootstrapk8s.io/code-generatork8s.io/component-basek8s.io/component-helpersk8s.io/controller-managerk8s.io/cri-apik8s.io/cri-clientk8s.io/csi-translation-libk8s.io/dynamic-resource-allocationk8s.io/endpointslicek8s.io/externaljwtk8s.io/kmsk8s.io/kube-aggregatork8s.io/kube-controller-managerk8s.io/kube-proxyk8s.io/kube-schedulerk8s.io/kubectlk8s.io/kubeletk8s.io/metricsk8s.io/mount-utilsk8s.io/pod-security-admissionk8s.io/sample-apiserverk8s.io/sample-cli-plugink8s.io/sample-controller
The code in the staging/ directory is authoritative, i.e. the only copy of the code. You can directly modify such code.
Using staged repositories from Kubernetes code
Kubernetes code uses the repositories in this directory via a Go workspace and
module replace statements. For example, when Kubernetes code imports a
package from the k8s.io/client-go repository, that import is resolved to
staging/src/k8s.io/client-go relative to the project root:
// pkg/example/some_code.go
package example
import (
"k8s.io/client-go/dynamic" // resolves to staging/src/k8s.io/client-go/dynamic
)
Creating a new repository in staging
Adding the staging repository in kubernetes/kubernetes:
-
Send an email to the SIG Architecture mailing list and the mailing list of the SIG which would own the repo requesting approval for creating the staging repository.
-
Once approval has been granted, create the new staging repository.
-
Update
import-restrictions.yamlto add the list of other staging repos that this new repo can import. -
Add all mandatory template files to the staging repo as mentioned in https://github.com/kubernetes/kubernetes-template-project.
-
Make sure that the
.github/PULL_REQUEST_TEMPLATE.mdandCONTRIBUTING.mdfiles mention that PRs are not directly accepted to the repo. -
Ensure that
docs.gofile is added. Refer to #kubernetes/kubernetes#91354 for reference. -
NOTE: Do not edit go.mod or go.sum in the new repo (staging/src/k8s.io//) manually. Run the following instead:
./hack/update-vendor.sh
Creating the published repository
-
Create an issue in the
kubernetes/orgrepo to request creation of the respective published repository in the Kubernetes org. The published repository must have an initial empty commit. It also needs specific access rules and branch settings. See #kubernetes/org#58 for an example. -
Setup branch protection and enable access to the
stage-botsteam by adding the repo inprow/config.yaml. See #kubernetes/test-infra#9292 for an example. -
Once the repository has been created in the Kubernetes org, update the publishing-bot to publish the staging repository by updating:
-
rules.yaml: Make sure that the list of dependencies reflects the staging repos in theGodeps.jsonfile. -
repos.sh: Add the staging repo in the list of repos to be published.
-
-
Add the staging and published repositories as a subproject for the SIG that owns the repos in
sigs.yaml. -
Add the repo to the list of staging repos in this
README.mdfile.