add flag to kubelet to ignore the cidr passed down by the apiserver on the master

cluster/saltbase/salt/kubelet/default

@@ -22,6 +22,8 @@
   {% set api_servers_with_port = api_servers + ":6443" -%}
 {% endif -%}
 
+{% set master_kubelet_args = "" %}
+
 {% set debugging_handlers = "--enable-debugging-handlers=true" -%}
 
 {% if grains['roles'][0] == 'kubernetes-master' -%}
@@ -31,6 +33,7 @@
     # running on the master.
     {% if grains.kubelet_api_servers is defined -%}
       {% set api_servers_with_port = "--api-servers=https://" + grains.kubelet_api_servers -%}
+      {% set master_kubelet_args = master_kubelet_args + "--register-schedulable=false --reconcile-cidr=false" -%}
     {% else -%}
       {% set api_servers_with_port = "" -%}
     {% endif -%}
@@ -114,4 +117,4 @@
 {% endif -%}
 
 # test_args has to be kept at the end, so they'll overwrite any prior configuration
-DAEMON_ARGS="{{daemon_args}} {{api_servers_with_port}} {{debugging_handlers}} {{hostname_override}} {{cloud_provider}} {{config}} {{manifest_url}} --allow-privileged={{pillar['allow_privileged']}} {{pillar['log_level']}} {{cluster_dns}} {{cluster_domain}} {{docker_root}} {{kubelet_root}} {{configure_cbr0}} {{cgroup_root}} {{system_container}} {{pod_cidr}} {{cpu_cfs_quota}} {{network_plugin}} {{test_args}}"
+DAEMON_ARGS="{{daemon_args}} {{api_servers_with_port}} {{debugging_handlers}} {{hostname_override}} {{cloud_provider}} {{config}} {{manifest_url}} --allow-privileged={{pillar['allow_privileged']}} {{pillar['log_level']}} {{cluster_dns}} {{cluster_domain}} {{docker_root}} {{kubelet_root}} {{configure_cbr0}} {{cgroup_root}} {{system_container}} {{pod_cidr}} {{ master_kubelet_args }} {{cpu_cfs_quota}} {{network_plugin}} {{test_args}}"

cmd/kubelet/app/server.go

@@ -119,6 +119,7 @@ type KubeletServer struct {
 	Port                           uint
 	ReadOnlyPort                   uint
 	RegisterNode                   bool
+	RegisterSchedulable            bool
 	RegistryBurst                  int
 	RegistryPullQPS                float64
 	ResolverConfig                 string
@@ -133,6 +134,7 @@ type KubeletServer struct {
 	SystemContainer                string
 	TLSCertFile                    string
 	TLSPrivateKeyFile              string
+	ReconcileCIDR                  bool
 
 	// Flags intended for testing
 	// Is the kubelet containerized?
@@ -195,6 +197,7 @@ func NewKubeletServer() *KubeletServer {
 		Port:                ports.KubeletPort,
 		ReadOnlyPort:        ports.KubeletReadOnlyPort,
 		RegisterNode:        true, // will be ignored if no apiserver is configured
+		RegisterSchedulable: true,
 		RegistryBurst:       10,
 		ResourceContainer:   "/kubelet",
 		RktPath:             "",
@@ -202,6 +205,7 @@ func NewKubeletServer() *KubeletServer {
 		RootDirectory:       defaultRootDir,
 		SyncFrequency:       10 * time.Second,
 		SystemContainer:     "",
+		ReconcileCIDR:       true,
 	}
 }
 
@@ -279,6 +283,8 @@ func (s *KubeletServer) AddFlags(fs *pflag.FlagSet) {
 	fs.Float64Var(&s.ChaosChance, "chaos-chance", s.ChaosChance, "If > 0.0, introduce random client errors and latency. Intended for testing. [default=0.0]")
 	fs.BoolVar(&s.Containerized, "containerized", s.Containerized, "Experimental support for running kubelet in a container.  Intended for testing. [default=false]")
 	fs.Uint64Var(&s.MaxOpenFiles, "max-open-files", 1000000, "Number of files that can be opened by Kubelet process. [default=1000000]")
+	fs.BoolVar(&s.ReconcileCIDR, "reconcile-cidr", s.ReconcileCIDR, "Reconcile node CIDR with the CIDR specified by the API server. No-op if register-node or configure-cbr0 is false. [default=true]")
+	fs.BoolVar(&s.RegisterSchedulable, "register-schedulable", s.RegisterSchedulable, "Register the node as schedulable. No-op if register-node is false. [default=true]")
 }
 
 // KubeletConfig returns a KubeletConfig suitable for being run, or an error if the server setup
@@ -385,10 +391,12 @@ func (s *KubeletServer) KubeletConfig() (*KubeletConfig, error) {
 		OOMAdjuster:               oom.NewOOMAdjuster(),
 		OSInterface:               kubecontainer.RealOS{},
 		PodCIDR:                   s.PodCIDR,
+		ReconcileCIDR:             s.ReconcileCIDR,
 		PodInfraContainerImage:    s.PodInfraContainerImage,
 		Port:                           s.Port,
 		ReadOnlyPort:                   s.ReadOnlyPort,
 		RegisterNode:                   s.RegisterNode,
+		RegisterSchedulable:            s.RegisterSchedulable,
 		RegistryBurst:                  s.RegistryBurst,
 		RegistryPullQPS:                s.RegistryPullQPS,
 		ResolverConfig:                 s.ResolverConfig,
@@ -647,6 +655,7 @@ func SimpleKubelet(client *client.Client,
 		Port:                port,
 		ReadOnlyPort:        readOnlyPort,
 		RegisterNode:        true,
+		RegisterSchedulable: true,
 		ResolverConfig:      kubelet.ResolvConfDefault,
 		ResourceContainer:   "/kubelet",
 		RootDirectory:       rootDir,
@@ -827,12 +836,14 @@ type KubeletConfig struct {
 	OOMAdjuster                    *oom.OOMAdjuster
 	OSInterface                    kubecontainer.OSInterface
 	PodCIDR                        string
+	ReconcileCIDR                  bool
 	PodConfig                      *config.PodConfig
 	PodInfraContainerImage         string
 	Port                           uint
 	ReadOnlyPort                   uint
 	Recorder                       record.EventRecorder
 	RegisterNode                   bool
+	RegisterSchedulable            bool
 	RegistryBurst                  int
 	RegistryPullQPS                float64
 	ResolverConfig                 string
@@ -890,6 +901,7 @@ func CreateAndInitKubelet(kc *KubeletConfig) (k KubeletBootstrap, pc *config.Pod
 		gcPolicy,
 		pc.SeenAllSources,
 		kc.RegisterNode,
+		kc.RegisterSchedulable,
 		kc.StandaloneMode,
 		kc.ClusterDomain,
 		kc.ClusterDNS,
@@ -916,6 +928,7 @@ func CreateAndInitKubelet(kc *KubeletConfig) (k KubeletBootstrap, pc *config.Pod
 		kc.SystemContainer,
 		kc.ConfigureCBR0,
 		kc.PodCIDR,
+		kc.ReconcileCIDR,
 		kc.MaxPods,
 		kc.DockerExecHandler,
 		kc.ResolverConfig,

contrib/mesos/pkg/executor/service/service.go

@@ -322,6 +322,7 @@ func (ks *KubeletExecutorServer) createAndInitKubelet(
 		gcPolicy,
 		pc.SeenAllSources,
 		kc.RegisterNode,
+		kc.RegisterSchedulable,
 		kc.StandaloneMode,
 		kc.ClusterDomain,
 		net.IP(kc.ClusterDNS),
@@ -348,6 +349,7 @@ func (ks *KubeletExecutorServer) createAndInitKubelet(
 		kc.SystemContainer,
 		kc.ConfigureCBR0,
 		kc.PodCIDR,
+		kc.ReconcileCIDR,
 		kc.MaxPods,
 		kc.DockerExecHandler,
 		kc.ResolverConfig,

hack/verify-flags/known-flags.txt

@@ -301,4 +301,6 @@ retry_time
 file_content_in_loop
 cpu-cfs-quota
 terminated-pod-gc-threshold
+reconcile-cidr
+register-schedulable
 

pkg/kubelet/kubelet.go

@@ -150,6 +150,7 @@ func NewMainKubelet(
 	containerGCPolicy ContainerGCPolicy,
 	sourcesReady SourcesReadyFn,
 	registerNode bool,
+	registerSchedulable bool,
 	standaloneMode bool,
 	clusterDomain string,
 	clusterDNS net.IP,
@@ -176,6 +177,7 @@ func NewMainKubelet(
 	systemContainer string,
 	configureCBR0 bool,
 	podCIDR string,
+	reconcileCIDR bool,
 	pods int,
 	dockerExecHandler dockertools.ExecHandler,
 	resolverConfig string,
@@ -263,6 +265,7 @@ func NewMainKubelet(
 		httpClient:                     &http.Client{},
 		sourcesReady:                   sourcesReady,
 		registerNode:                   registerNode,
+		registerSchedulable:            registerSchedulable,
 		standaloneMode:                 standaloneMode,
 		clusterDomain:                  clusterDomain,
 		clusterDNS:                     clusterDNS,
@@ -290,6 +293,7 @@ func NewMainKubelet(
 		writer:                         writer,
 		configureCBR0:                  configureCBR0,
 		podCIDR:                        podCIDR,
+		reconcileCIDR:                  reconcileCIDR,
 		pods:                           pods,
 		syncLoopMonitor:                util.AtomicValue{},
 		resolverConfig:                 resolverConfig,
@@ -465,6 +469,8 @@ type Kubelet struct {
 
 	// Set to true to have the node register itself with the apiserver.
 	registerNode bool
+	// Set to true to have the node register itself as schedulable.
+	registerSchedulable bool
 	// for internal book keeping; access only from within registerWithApiserver
 	registrationCompleted bool
 
@@ -574,6 +580,7 @@ type Kubelet struct {
 	// the correct state.
 	configureCBR0 bool
 	podCIDR       string
+	reconcileCIDR bool
 
 	// Number of Pods which can be run by this Kubelet
 	pods int
@@ -819,6 +826,9 @@ func (kl *Kubelet) initialNodeStatus() (*api.Node, error) {
 			Name:   kl.nodeName,
 			Labels: map[string]string{"kubernetes.io/hostname": kl.hostname},
 		},
+		Spec: api.NodeSpec{
+			Unschedulable: !kl.registerSchedulable,
+		},
 	}
 	if kl.cloud != nil {
 		instances, ok := kl.cloud.Instances()
@@ -2453,7 +2463,9 @@ func (kl *Kubelet) tryUpdateNodeStatus() error {
 		return fmt.Errorf("no node instance returned for %q", kl.nodeName)
 	}
 	kl.networkConfigMutex.Lock()
+	if kl.reconcileCIDR {
 		kl.podCIDR = node.Spec.PodCIDR
+	}
 	kl.networkConfigMutex.Unlock()
 
 	if err := kl.setNodeStatus(node); err != nil {