client-go features: ignore contextual logging

The client-go feature gates implementation logs information about feature
states at V(1). Changing that would imply changing the Enabled method, which is
very intrusive because there are many callers which are not expected to log and
thus don't have access to a contextual logger.

The code is not active in Kubernetes components, those use the clientAdapter to
make client-go use the normal feature gate implementation, which doesn't log
anything. Therefore the code doesn't get changed and only annotated so that
logcheck won't complain.

Kubernetes-commit: e47b186e6ba3cbc9c732409ef9037e883ea80da1
This commit is contained in:
Patrick Ohly
2024-12-09 13:00:47 +01:00
committed by Kubernetes Publisher
parent 09da9b25fa
commit 5da30e54b3
2 changed files with 15 additions and 6 deletions

View File

@@ -141,6 +141,13 @@ func (f *envVarFeatureGates) Set(featureName Feature, featureValue bool) error {
// read from the corresponding environmental variable.
func (f *envVarFeatureGates) getEnabledMapFromEnvVar() map[Feature]bool {
f.readEnvVarsOnce.Do(func() {
// This code does not really support contextual logging. Making it do so has huge
// implications for several call chains because the Enabled call then needs
// a `*WithLogger` variant. This does not matter in Kubernetes itself because
// all Kubernetes components replace the feature gate implementation used
// by client-go, but it might matter elsewhere.
logger := klog.Background()
featureGatesState := map[Feature]bool{}
for feature, featureSpec := range f.known {
featureState, featureStateSet := os.LookupEnv(fmt.Sprintf("KUBE_FEATURE_%s", feature))
@@ -150,10 +157,10 @@ func (f *envVarFeatureGates) getEnabledMapFromEnvVar() map[Feature]bool {
boolVal, boolErr := strconv.ParseBool(featureState)
switch {
case boolErr != nil:
utilruntime.HandleError(fmt.Errorf("cannot set feature gate %q to %q, due to %v", feature, featureState, boolErr))
utilruntime.HandleErrorWithLogger(logger, boolErr, "Could not set feature gate", "feature", feature, "desiredState", featureState)
case featureSpec.LockToDefault:
if boolVal != featureSpec.Default {
utilruntime.HandleError(fmt.Errorf("cannot set feature gate %q to %q, feature is locked to %v", feature, featureState, featureSpec.Default))
utilruntime.HandleErrorWithLogger(logger, nil, "Could not set feature gate, feature is locked", "feature", feature, "desiredState", featureState, "lockedState", featureSpec.Default)
break
}
featureGatesState[feature] = featureSpec.Default
@@ -166,10 +173,10 @@ func (f *envVarFeatureGates) getEnabledMapFromEnvVar() map[Feature]bool {
for feature, featureSpec := range f.known {
if featureState, ok := featureGatesState[feature]; ok {
klog.V(1).InfoS("Feature gate updated state", "feature", feature, "enabled", featureState)
logger.V(1).Info("Feature gate updated state", "feature", feature, "enabled", featureState)
continue
}
klog.V(1).InfoS("Feature gate default state", "feature", feature, "enabled", featureSpec.Default)
logger.V(1).Info("Feature gate default state", "feature", feature, "enabled", featureSpec.Default)
}
})
return f.enabledViaEnvVar.Load().(map[Feature]bool)

View File

@@ -17,7 +17,7 @@ limitations under the License.
package features
import (
"errors"
"context"
"sync/atomic"
utilruntime "k8s.io/apimachinery/pkg/util/runtime"
@@ -127,7 +127,9 @@ func AddVersionedFeaturesToExistingFeatureGates(registry VersionedRegistry) erro
// clientgofeaturegate.ReplaceFeatureGates(utilfeature.DefaultMutableFeatureGate)
func ReplaceFeatureGates(newFeatureGates Gates) {
if replaceFeatureGatesWithWarningIndicator(newFeatureGates) {
utilruntime.HandleError(errors.New("the default feature gates implementation has already been used and now it's being overwritten. This might lead to unexpected behaviour. Check your initialization order"))
// TODO (?): A new API would be needed where callers pass in a context or logger.
// Probably not worth it.
utilruntime.HandleErrorWithContext(context.TODO(), nil, "The default feature gates implementation has already been used and now it's being overwritten. This might lead to unexpected behaviour. Check your initialization order.")
}
}