Merge pull request #4831 from timebertt/promote/cachedruntimeclients

Promote CachedRuntimeClients feature gate to beta
gardener · Oct 14, 2021 · 424290b · 424290b
2 parents 69f56d7 + 1a4cecd
commit 424290b
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diff --git a/docs/deployment/feature_gates.md b/docs/deployment/feature_gates.md
@@ -27,7 +27,8 @@ The following tables are a summary of the feature gates that you can set on diff
 | ManagedIstio | `true` | `Beta` | `1.19` | |
 | APIServerSNI | `false` | `Alpha` | `1.7` | `1.18` |
 | APIServerSNI | `true` | `Beta` | `1.19` | |
-| CachedRuntimeClients | `false` | `Alpha` | `1.7` | |
+| CachedRuntimeClients | `false` | `Alpha` | `1.7` | `1.33` |
+| CachedRuntimeClients | `true` | `Beta` | `1.34` | |
 | SeedChange | `false` | `Alpha` | `1.12` | |
 | SeedKubeScheduler | `false` | `Alpha` | `1.15` | |
 | ReversedVPN | `false` | `Alpha` | `1.22` | |

diff --git a/docs/development/kubernetes-clients.md b/docs/development/kubernetes-clients.md
@@ -185,10 +185,11 @@ This means, that if you read the same object from different cache implementation
 
 By default, the `client.Client` created by a controller-runtime `Manager` is a `DelegatingClient`. It delegates `Get` and `List` calls to a `Cache` and all other calls to a client, that talks directly to the API server. Exceptions are requests with `*unstructured.Unstructured` objects and object kinds that were configured to be excluded from the cache in the `DelegatingClient`.
 
-> ℹ️ Currently, the controller-runtime client contained in Gardener's client collection (`kubernetes.Interface.Client()`) is not cached and does not use the cache contained in the client set (`kubernetes.Interface.Cache()`). This means, the client always reads directly from the API server, but you can intentionally read from the cache if desired.
->
-> If the `CachedRuntimeClients` feature gate is enabled, `Client()` returns a `DelegatingClient` that uses the cache returned from `Cache()` under the hood. This means, all `Client()` usages should be ready for cached clients and should be able to cater with stale cache reads.
-> See [gardener/gardener#2822](https://github.com/gardener/gardener/issues/2822) for details on the graduation progress.
+> ℹ️
+> If the `CachedRuntimeClients` feature gate is enabled (enabled by default starting from `v1.34`), `kubernetes.Interface.Client()` returns a `DelegatingClient` that uses the cache returned from `kubernetes.Interface.Cache()` under the hood. This means, all `Client()` usages need to be ready for cached clients and should be able to cater with stale cache reads.
+> See [gardener/gardener#2822](https://github.com/gardener/gardener/issues/2822) for details on the graduation progress to beta.
+> 
+> If the feature gate is explicitly disabled, the controller-runtime client (`kubernetes.Interface.Client()`) is not cached and does not use the cache contained in the client set (`kubernetes.Interface.Cache()`). This means, the client always reads directly from the API server, but you can intentionally read from the cache if desired.
 
 _Important characteristics of cached controller-runtime clients:_
 

diff --git a/pkg/client/kubernetes/client.go b/pkg/client/kubernetes/client.go
@@ -40,9 +40,10 @@ import (
 )
 
 var (
-	// UseCachedRuntimeClients is a flag for enabling cached controller-runtime clients (defaults to false).
-	// If enabled, the client returned by Interface.Client() will be backed by a cache, otherwise it will talk directly
-	// to the API server.
+	// UseCachedRuntimeClients is a flag for enabling cached controller-runtime clients. The CachedRuntimeClients feature
+	// gate (enabled by default sinde v1.34) causes this flag to be set to true.
+	// If enabled, the client returned by Interface.Client() will be backed by Interface.Cache(), otherwise it will talk
+	// directly to the API server.
 	UseCachedRuntimeClients = false
 )
 

diff --git a/pkg/controllermanager/features/features.go b/pkg/controllermanager/features/features.go
@@ -25,7 +25,7 @@ var (
 	// FeatureGate is a shared global FeatureGate for Gardener Controller Manager flags.
 	FeatureGate  = featuregate.NewFeatureGate()
 	featureGates = map[featuregate.Feature]featuregate.FeatureSpec{
-		features.CachedRuntimeClients:          {Default: false, PreRelease: featuregate.Alpha},
+		features.CachedRuntimeClients:          {Default: true, PreRelease: featuregate.Beta},
 		features.UseDNSRecords:                 {Default: false, PreRelease: featuregate.Alpha},
 		features.RotateSSHKeypairOnMaintenance: {Default: false, PreRelease: featuregate.Alpha},
 	}

diff --git a/pkg/features/features.go b/pkg/features/features.go
@@ -61,8 +61,9 @@ const (
 
 	// CachedRuntimeClients enables a cache in the controller-runtime clients, that Gardener uses.
 	// If disabled all controller-runtime clients will directly talk to the API server instead of relying on a cache.
-	// owner @tim-ebert
+	// owner @timebertt
 	// alpha: v1.7.0
+	// beta: v1.34.0
 	CachedRuntimeClients featuregate.Feature = "CachedRuntimeClients"
 
 	// SeedChange enables updating the `spec.seedName` field during shoot validation from a non-empty value

diff --git a/pkg/gardenlet/features/features.go b/pkg/gardenlet/features/features.go
@@ -30,7 +30,7 @@ var (
 		features.HVPAForShootedSeed:            {Default: false, PreRelease: featuregate.Alpha},
 		features.ManagedIstio:                  {Default: true, PreRelease: featuregate.Beta},
 		features.APIServerSNI:                  {Default: true, PreRelease: featuregate.Beta},
-		features.CachedRuntimeClients:          {Default: false, PreRelease: featuregate.Alpha},
+		features.CachedRuntimeClients:          {Default: true, PreRelease: featuregate.Beta},
 		features.SeedKubeScheduler:             {Default: false, PreRelease: featuregate.Alpha},
 		features.ReversedVPN:                   {Default: false, PreRelease: featuregate.Alpha},
 		features.UseDNSRecords:                 {Default: false, PreRelease: featuregate.Alpha},