Fail on swap enabled and deprecate experimental-fail-swap-on flag

cmd/kubelet/app/options/options.go

@@ -144,8 +144,9 @@ func (f *KubeletFlags) AddFlags(fs *pflag.FlagSet) {
 
 // addFlags adds flags for a specific componentconfig.KubeletConfiguration to the specified FlagSet
 func (c *kubeletConfiguration) addFlags(fs *pflag.FlagSet) {
-	// TODO(#34726:1.8.0): Remove the opt-in for failing when swap is enabled.
-	fs.BoolVar(&c.ExperimentalFailSwapOn, "experimental-fail-swap-on", c.ExperimentalFailSwapOn, "Makes the Kubelet fail to start if swap is enabled on the node. This is a temporary opton to maintain legacy behavior, failing due to swap enabled will happen by default in v1.6.")
+	fs.BoolVar(&c.FailSwapOn, "fail-swap-on", true, "Makes the Kubelet fail to start if swap is enabled on the node. ")
+	fs.BoolVar(&c.FailSwapOn, "experimental-fail-swap-on", true, "DEPRECATED: please use --fail-swap-on instead.")
+	fs.MarkDeprecated("experimental-fail-swap-on", "This flag is deprecated and will be removed in future releases. please use --fail-swap-on instead.")
 
 	fs.StringVar(&c.PodManifestPath, "pod-manifest-path", c.PodManifestPath, "Path to to the directory containing pod manifest files to run, or the path to a single pod manifest file. Files starting with dots will be ignored.")
 	fs.DurationVar(&c.SyncFrequency.Duration, "sync-frequency", c.SyncFrequency.Duration, "Max period between synchronizing running containers and config")

cmd/kubelet/app/server.go

@@ -584,7 +584,7 @@ func run(s *options.KubeletServer, kubeDeps *kubelet.Dependencies) (err error) {
 				},
 				ExperimentalQOSReserved: *experimentalQOSReserved,
 			},
-			s.ExperimentalFailSwapOn,
+			s.FailSwapOn,
 			kubeDeps.Recorder)
 
 		if err != nil {

hack/verify-flags/known-flags.txt

@@ -271,6 +271,7 @@ external-hostname
 external-ip
 external-name
 extra-peer-dirs
+fail-swap-on
 failover-timeout
 failure-domains
 fake-clientset

pkg/apis/componentconfig/types.go

@@ -465,9 +465,8 @@ type KubeletConfiguration struct {
 	// featureGates is a string of comma-separated key=value pairs that describe feature
 	// gates for alpha/experimental features.
 	FeatureGates string
-	// TODO(#34726:1.8.0): Remove the opt-in for failing when swap is enabled.
 	// Tells the Kubelet to fail to start if swap is enabled on the node.
-	ExperimentalFailSwapOn bool
+	FailSwapOn bool
 	// This flag, if set, enables a check prior to mount operations to verify that the required components
 	// (binaries, etc.) to mount the volume are available on the underlying node. If the check is enabled
 	// and fails the mount operation fails.

pkg/apis/componentconfig/v1alpha1/types.go

@@ -530,9 +530,8 @@ type KubeletConfiguration struct {
 	// featureGates is a string of comma-separated key=value pairs that describe feature
 	// gates for alpha/experimental features.
 	FeatureGates string `json:"featureGates,omitempty"`
-	// TODO(#34726:1.8.0): Remove the opt-in for failing when swap is enabled.
 	// Tells the Kubelet to fail to start if swap is enabled on the node.
-	ExperimentalFailSwapOn bool `json:"experimentalFailSwapOn,omitempty"`
+	FailSwapOn bool `json:"failSwapOn,omitempty"`
 	// This flag, if set, enables a check prior to mount operations to verify that the required components
 	// (binaries, etc.) to mount the volume are available on the underlying node. If the check is enabled
 	// and fails the mount operation fails.

pkg/apis/componentconfig/v1alpha1/zz_generated.conversion.go

@@ -504,7 +504,7 @@ func autoConvert_v1alpha1_KubeletConfiguration_To_componentconfig_KubeletConfigu
 	}
 	out.AllowedUnsafeSysctls = *(*[]string)(unsafe.Pointer(&in.AllowedUnsafeSysctls))
 	out.FeatureGates = in.FeatureGates
-	out.ExperimentalFailSwapOn = in.ExperimentalFailSwapOn
+	out.FailSwapOn = in.FailSwapOn
 	out.ExperimentalCheckNodeCapabilitiesBeforeMount = in.ExperimentalCheckNodeCapabilitiesBeforeMount
 	out.KeepTerminatedPodVolumes = in.KeepTerminatedPodVolumes
 	out.SystemReserved = *(*componentconfig.ConfigurationMap)(unsafe.Pointer(&in.SystemReserved))
@@ -686,7 +686,7 @@ func autoConvert_componentconfig_KubeletConfiguration_To_v1alpha1_KubeletConfigu
 	}
 	out.AllowedUnsafeSysctls = *(*[]string)(unsafe.Pointer(&in.AllowedUnsafeSysctls))
 	out.FeatureGates = in.FeatureGates
-	out.ExperimentalFailSwapOn = in.ExperimentalFailSwapOn
+	out.FailSwapOn = in.FailSwapOn
 	out.ExperimentalCheckNodeCapabilitiesBeforeMount = in.ExperimentalCheckNodeCapabilitiesBeforeMount
 	out.KeepTerminatedPodVolumes = in.KeepTerminatedPodVolumes
 	out.SystemReserved = *(*map[string]string)(unsafe.Pointer(&in.SystemReserved))

pkg/kubelet/cm/container_manager_linux.go

@@ -204,18 +204,14 @@ func NewContainerManager(mountUtil mount.Interface, cadvisorInterface cadvisor.I
 		return nil, err
 	}
 
-	// TODO(#34726:1.8.0): Remove the opt-in for failing when swap is enabled.
-	//     Running with swap enabled should be considered an error, but in order to maintain legacy
-	//     behavior we have to require an opt-in to this error for a period of time.
-
-	// If there is more than one line (table headers) in /proc/swaps, swap is enabled and we should error out.
+	// Running with swap enabled should be considered an error, but in order to maintain legacy
+	// behavior we have to require an opt-in to this error for a period of time.
+	// If there is more than one line (table headers) in /proc/swaps, swap is enabled and we should
+	// error out unless --fail-swap-on is set to false.
 	if len(buf) > 1 {
 		if failSwapOn {
-			return nil, fmt.Errorf("Running with swap on is not supported, please disable swap! /proc/swaps contained: %v", buf)
+			return nil, fmt.Errorf("Running with swap on is not supported, please disable swap! or set --fail-swap-on flag to false. /proc/swaps contained: %v", buf)
 		}
-		glog.Warningf("Running with swap on is not supported, please disable swap! " +
-			"This will be a fatal error by default starting in K8s v1.6! " +
-			"In the meantime, you can opt-in to making this a fatal error by enabling --experimental-fail-swap-on.")
 	}
 	var capacity = v1.ResourceList{}
 	// It is safe to invoke `MachineInfo` on cAdvisor before logically initializing cAdvisor here because