Add cgroup driver and cgroups-per-qos flags to kubelet

cmd/kubelet/app/options/options.go

@@ -164,7 +164,8 @@ func (s *KubeletServer) AddFlags(fs *pflag.FlagSet) {
 	fs.MarkDeprecated("system-container", "Use --system-cgroups instead. Will be removed in a future version.")
 	fs.StringVar(&s.SystemCgroups, "system-cgroups", s.SystemCgroups, "Optional absolute name of cgroups in which to place all non-kernel processes that are not already inside a cgroup under `/`. Empty for no container. Rolling back the flag requires a reboot. (Default: \"\").")
 
-	//fs.BoolVar(&s.CgroupsPerQOS, "cgroups-per-qos", s.CgroupsPerQOS, "Enable creation of QoS cgroup hierarchy, if true top level QoS and pod cgroups are created.")
+	fs.BoolVar(&s.CgroupsPerQOS, "cgroups-per-qos", s.CgroupsPerQOS, "Enable creation of QoS cgroup hierarchy, if true top level QoS and pod cgroups are created.")
+	fs.StringVar(&s.CgroupDriver, "cgroup-driver", s.CgroupDriver, "Driver that the kubelet uses to manipulate cgroups on the host.  Possible values: 'cgroupfs', 'systemd'")
 	fs.StringVar(&s.CgroupRoot, "cgroup-root", s.CgroupRoot, "Optional root cgroup to use for pods. This is handled by the container runtime on a best effort basis. Default: '', which means use the container runtime default.")
 	fs.StringVar(&s.ContainerRuntime, "container-runtime", s.ContainerRuntime, "The container runtime to use. Possible values: 'docker', 'rkt'. Default: 'docker'.")
 	fs.DurationVar(&s.RuntimeRequestTimeout.Duration, "runtime-request-timeout", s.RuntimeRequestTimeout.Duration, "Timeout of all runtime requests except long running request - pull, logs, exec and attach. When timeout exceeded, kubelet will cancel the request, throw out an error and retry later. Default: 2m0s")

pkg/apis/componentconfig/types.go

@@ -279,7 +279,9 @@ type KubeletConfiguration struct {
 	// Enable QoS based Cgroup hierarchy: top level cgroups for QoS Classes
 	// And all Burstable and BestEffort pods are brought up under their
 	// specific top level QoS cgroup.
-	CgroupsPerQOS bool `json:"CgroupsPerQOS,omitempty"`
+	CgroupsPerQOS bool `json:"cgroupsPerQOS,omitempty"`
+	// driver that the kubelet uses to manipulate cgroups on the host (cgroupfs or systemd)
+	CgroupDriver string `json:"cgroupDriver,omitempty"`
 	// Cgroups that container runtime is expected to be isolated in.
 	RuntimeCgroups string `json:"runtimeCgroups,omitempty"`
 	// SystemCgroups is absolute name of cgroups in which to place

pkg/apis/componentconfig/v1alpha1/defaults.go

@@ -351,6 +351,13 @@ func SetDefaults_KubeletConfiguration(obj *KubeletConfiguration) {
 		temp := int32(defaultIPTablesDropBit)
 		obj.IPTablesDropBit = &temp
 	}
+	if obj.CgroupDriver == "" {
+		obj.CgroupDriver = "cgroupfs"
+	}
+	if obj.CgroupsPerQOS == nil {
+		temp := false
+		obj.CgroupsPerQOS = &temp
+	}
 }
 
 func boolVar(b bool) *bool {

pkg/apis/componentconfig/v1alpha1/types.go

@@ -343,7 +343,9 @@ type KubeletConfiguration struct {
 	// Enable QoS based Cgroup hierarchy: top level cgroups for QoS Classes
 	// And all Burstable and BestEffort pods are brought up under their
 	// specific top level QoS cgroup.
-	CgroupsPerQOS *bool `json:"CgroupsPerQOS,omitempty"`
+	CgroupsPerQOS *bool `json:"cgroupsPerQOS,omitempty"`
+	// driver that the kubelet uses to manipulate cgroups on the host (cgroupfs or systemd)
+	CgroupDriver string `json:"cgroupDriver,omitempty"`
 	// containerRuntime is the container runtime to use.
 	ContainerRuntime string `json:"containerRuntime"`
 	// remoteRuntimeEndpoint is the endpoint of remote runtime service