Remove VolumeSubpathEnvExpansion

pkg/api/pod/util.go

@@ -350,7 +350,7 @@ func dropDisabledFields(
 		}
 	}
 
-	if (!utilfeature.DefaultFeatureGate.Enabled(features.VolumeSubpath) || !utilfeature.DefaultFeatureGate.Enabled(features.VolumeSubpathEnvExpansion)) && !subpathExprInUse(oldPodSpec) {
+	if !subpathExprInUse(oldPodSpec) {
 		// drop subpath env expansion from the pod if either of the subpath features is disabled and the old spec did not specify subpath env expansion
 		for i := range podSpec.Containers {
 			for j := range podSpec.Containers[i].VolumeMounts {

pkg/features/kube_features.go

@@ -255,13 +255,6 @@ const (
 	// Allow user to specify additional conditions to be evaluated for Pod readiness.
 	PodReadinessGates utilfeature.Feature = "PodReadinessGates"
 
-	// owner: @kevtaylor
-	// alpha: v1.11
-	//
-	// Allow subpath environment variable substitution
-	// Only applicable if the VolumeSubpath feature is also enabled
-	VolumeSubpathEnvExpansion utilfeature.Feature = "VolumeSubpathEnvExpansion"
-
 	// owner: @vikaschoudhary16
 	// GA: v1.13
 	//
@@ -419,7 +412,6 @@ var defaultKubernetesFeatureGates = map[utilfeature.Feature]utilfeature.FeatureS
 	CSIMigrationOpenStack:                   {Default: false, PreRelease: utilfeature.Alpha},
 	VolumeSubpath:                           {Default: true, PreRelease: utilfeature.GA},
 	PodReadinessGates:                       {Default: true, PreRelease: utilfeature.GA, LockToDefault: true}, // remove in 1.16
-	VolumeSubpathEnvExpansion:               {Default: false, PreRelease: utilfeature.Alpha},
 	KubeletPluginsWatcher:                   {Default: true, PreRelease: utilfeature.GA, LockToDefault: true}, // remove in 1.16
 	ResourceQuotaScopeSelectors:             {Default: true, PreRelease: utilfeature.Beta},
 	CSIBlockVolume:                          {Default: true, PreRelease: utilfeature.Beta},

pkg/kubelet/container/helpers.go

@@ -23,11 +23,10 @@ import (
 
 	"k8s.io/klog"
 
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/types"
-	"k8s.io/apimachinery/pkg/util/sets"
 	"k8s.io/client-go/tools/record"
 	runtimeapi "k8s.io/kubernetes/pkg/kubelet/apis/cri/runtime/v1alpha2"
 	"k8s.io/kubernetes/pkg/kubelet/util/format"
@@ -131,24 +130,6 @@ func ExpandContainerCommandOnlyStatic(containerCommand []string, envs []v1.EnvVa
 	return command
 }
 
-func ExpandContainerVolumeMounts(mount v1.VolumeMount, envs []EnvVar) (string, error) {
-
-	envmap := EnvVarsToMap(envs)
-	missingKeys := sets.NewString()
-	expanded := expansion.Expand(mount.SubPathExpr, func(key string) string {
-		value, ok := envmap[key]
-		if !ok || len(value) == 0 {
-			missingKeys.Insert(key)
-		}
-		return value
-	})
-
-	if len(missingKeys) > 0 {
-		return "", fmt.Errorf("missing value for %s", strings.Join(missingKeys.List(), ", "))
-	}
-	return expanded, nil
-}
-
 func ExpandContainerCommandAndArgs(container *v1.Container, envs []EnvVar) (command []string, args []string) {
 	mapping := expansion.MappingFuncFor(EnvVarsToMap(envs))
 

pkg/kubelet/kubelet_pods.go

@@ -32,7 +32,7 @@ import (
 	"strings"
 	"sync"
 
-	"k8s.io/api/core/v1"
+	v1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/labels"
@@ -167,15 +167,7 @@ func makeMounts(pod *v1.Pod, podDir string, container *v1.Container, hostName, h
 				return nil, cleanupAction, fmt.Errorf("volume subpaths are disabled")
 			}
 
-			if !utilfeature.DefaultFeatureGate.Enabled(features.VolumeSubpathEnvExpansion) {
-				return nil, cleanupAction, fmt.Errorf("volume subpath expansion is disabled")
-			}
-
-			subPath, err = kubecontainer.ExpandContainerVolumeMounts(mount, expandEnvs)
-
-			if err != nil {
-				return nil, cleanupAction, err
-			}
+			return nil, cleanupAction, fmt.Errorf("volume subpath expansion is disabled")
 		}
 
 		if subPath != "" {