Make system container name configurable.

(cherry picked from commit 9a2630ac6e)

cmd/kubelet/app/server.go

@@ -108,6 +108,7 @@ type KubeletServer struct {
 	CgroupRoot                     string
 	ContainerRuntime               string
 	DockerDaemonContainer          string
+	SystemContainer                string
 	ConfigureCBR0                  bool
 	MaxPods                        int
 
@@ -170,6 +171,7 @@ func NewKubeletServer() *KubeletServer {
 		CgroupRoot:                  "",
 		ContainerRuntime:            "docker",
 		DockerDaemonContainer:       "/docker-daemon",
+		SystemContainer:             "",
 		ConfigureCBR0:               false,
 	}
 }
@@ -228,7 +230,7 @@ func (s *KubeletServer) AddFlags(fs *pflag.FlagSet) {
 	fs.StringVar(&s.ResourceContainer, "resource-container", s.ResourceContainer, "Absolute name of the resource-only container to create and run the Kubelet in (Default: /kubelet).")
 	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.StringVar(&s.DockerDaemonContainer, "docker-daemon-container", s.DockerDaemonContainer, "Optional resource-only container in which to place the Docker Daemon. Empty for no container (Default: /docker-daemon).")
+	fs.StringVar(&s.SystemContainer, "system-container", s.SystemContainer, "Optional resource-only container in which to place all non-kernel processes that are not already in a container. Empty for no container. Rolling back the flag requires a reboot. (Default: \"\").")
 	fs.BoolVar(&s.ConfigureCBR0, "configure-cbr0", s.ConfigureCBR0, "If true, kubelet will configure cbr0 based on Node.Spec.PodCIDR.")
 	fs.IntVar(&s.MaxPods, "max-pods", 100, "Number of Pods that can run on this Kubelet.")
 
@@ -347,6 +349,7 @@ func (s *KubeletServer) Run(_ []string) error {
 		ContainerRuntime:          s.ContainerRuntime,
 		Mounter:                   mounter,
 		DockerDaemonContainer:     s.DockerDaemonContainer,
+		SystemContainer:           s.SystemContainer,
 		ConfigureCBR0:             s.ConfigureCBR0,
 		MaxPods:                   s.MaxPods,
 	}
@@ -513,6 +516,7 @@ func SimpleKubelet(client *client.Client,
 		ContainerRuntime:          "docker",
 		Mounter:                   mount.New(),
 		DockerDaemonContainer:     "/docker-daemon",
+		SystemContainer:           "",
 		MaxPods:                   32,
 	}
 	return &kcfg
@@ -648,6 +652,7 @@ type KubeletConfig struct {
 	ContainerRuntime               string
 	Mounter                        mount.Interface
 	DockerDaemonContainer          string
+	SystemContainer                string
 	ConfigureCBR0                  bool
 	MaxPods                        int
 }
@@ -701,6 +706,7 @@ func createAndInitKubelet(kc *KubeletConfig) (k KubeletBootstrap, pc *config.Pod
 		kc.ContainerRuntime,
 		kc.Mounter,
 		kc.DockerDaemonContainer,
+		kc.SystemContainer,
 		kc.ConfigureCBR0,
 		kc.MaxPods)
 

pkg/kubelet/kubelet.go

@@ -139,6 +139,7 @@ func NewMainKubelet(
 	containerRuntime string,
 	mounter mount.Interface,
 	dockerDaemonContainer string,
+	systemContainer string,
 	configureCBR0 bool,
 	pods int) (*Kubelet, error) {
 	if rootDirectory == "" {
@@ -298,10 +299,9 @@ func NewMainKubelet(
 		return nil, fmt.Errorf("unsupported container runtime %q specified", containerRuntime)
 	}
 
-	// TODO(vmarmol): Make configurable.
 	// Setup container manager, can fail if the devices hierarchy is not mounted
 	// (it is required by Docker however).
-	containerManager, err := newContainerManager(dockerDaemonContainer, "/system")
+	containerManager, err := newContainerManager(dockerDaemonContainer, systemContainer)
 	if err != nil {
 		return nil, fmt.Errorf("failed to create the Container Manager: %v", err)
 	}