Fix the container bridge so that it can create cbr0

Fix the kubelet so that it tries to sync status, even if Docker is down

cluster/saltbase/salt/docker/docker-defaults

@@ -3,9 +3,5 @@ DOCKER_OPTS=""
 DOCKER_OPTS="${DOCKER_OPTS} {{grains.docker_opts}}"
 {% endif %}
 
-{% set docker_bridge = "" %}
-{% if grains['roles'][0] == 'kubernetes-pool' %}
-  {% set docker_bridge = "--bridge cbr0" %}
-{% endif %} 
-DOCKER_OPTS="${DOCKER_OPTS} {{docker_bridge}} --iptables=false --ip-masq=false"
+DOCKER_OPTS="${DOCKER_OPTS} --bridge=cbr0 --iptables=false --ip-masq=false"
 DOCKER_NOFILE=1000000

cluster/saltbase/salt/kubelet/default

@@ -76,4 +76,9 @@
   {% set cgroup_root = "--cgroup_root=/" -%}
 {% endif -%}
 
-DAEMON_ARGS="{{daemon_args}} {{api_servers_with_port}} {{debugging_handlers}} {{hostname_override}} {{cloud_provider}} {{config}} --allow_privileged={{pillar['allow_privileged']}} {{pillar['log_level']}} {{cluster_dns}} {{cluster_domain}} {{docker_root}} {{kubelet_root}} {{configure_cbr0}} {{cgroup_root}} {{system_container}}"
+{% set pod_cidr = "" %}
+{% if grains['roles'][0] == 'kubernetes-master' %}
+  {% set pod_cidr = "--pod-cidr=" + grains['cbr-cidr'] %}
+{% endif %} 
+
+DAEMON_ARGS="{{daemon_args}} {{api_servers_with_port}} {{debugging_handlers}} {{hostname_override}} {{cloud_provider}} {{config}} --allow_privileged={{pillar['allow_privileged']}} {{pillar['log_level']}} {{cluster_dns}} {{cluster_domain}} {{docker_root}} {{kubelet_root}} {{configure_cbr0}} {{cgroup_root}} {{system_container}} {{pod_cidr}}"

cmd/kubelet/app/server.go

@@ -115,6 +115,7 @@ type KubeletServer struct {
 	DockerDaemonContainer          string
 	SystemContainer                string
 	ConfigureCBR0                  bool
+	PodCIDR                        string
 	MaxPods                        int
 	DockerExecHandlerName          string
 
@@ -241,7 +242,7 @@ func (s *KubeletServer) AddFlags(fs *pflag.FlagSet) {
 	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.")
 	fs.StringVar(&s.DockerExecHandlerName, "docker-exec-handler", s.DockerExecHandlerName, "Handler to use when executing a command in a container. Valid values are 'native' and 'nsenter'. Defaults to 'native'.")
-
+	fs.StringVar(&s.PodCIDR, "pod-cidr", "", "The CIDR to use for pod IP addresses, only used in standalone mode.  In cluster mode, this is obtained from the master.")
 	// Flags intended for testing, not recommended used in production environments.
 	fs.BoolVar(&s.ReallyCrashForTesting, "really-crash-for-testing", s.ReallyCrashForTesting, "If true, when panics occur crash. Intended for testing.")
 	fs.Float64Var(&s.ChaosChance, "chaos-chance", s.ChaosChance, "If > 0.0, introduce random client errors and latency. Intended for testing. [default=0.0]")
@@ -361,6 +362,7 @@ func (s *KubeletServer) Run(_ []string) error {
 		DockerDaemonContainer:     s.DockerDaemonContainer,
 		SystemContainer:           s.SystemContainer,
 		ConfigureCBR0:             s.ConfigureCBR0,
+		PodCIDR:                   s.PodCIDR,
 		MaxPods:                   s.MaxPods,
 		DockerExecHandler:         dockerExecHandler,
 	}
@@ -714,6 +716,7 @@ type KubeletConfig struct {
 	DockerDaemonContainer          string
 	SystemContainer                string
 	ConfigureCBR0                  bool
+	PodCIDR                        string
 	MaxPods                        int
 	DockerExecHandler              dockertools.ExecHandler
 }
@@ -771,6 +774,7 @@ func createAndInitKubelet(kc *KubeletConfig) (k KubeletBootstrap, pc *config.Pod
 		kc.DockerDaemonContainer,
 		kc.SystemContainer,
 		kc.ConfigureCBR0,
+		kc.PodCIDR,
 		kc.MaxPods,
 		kc.DockerExecHandler)
 

pkg/kubelet/container_bridge.go

@@ -19,6 +19,7 @@ package kubelet
 import (
 	"bytes"
 	"net"
+	"os"
 	"os/exec"
 	"regexp"
 
@@ -27,8 +28,39 @@ import (
 
 var cidrRegexp = regexp.MustCompile(`inet ([0-9a-fA-F.:]*/[0-9]*)`)
 
+func createCBR0(wantCIDR *net.IPNet) error {
+	// recreate cbr0 with wantCIDR
+	if err := exec.Command("brctl", "addbr", "cbr0").Run(); err != nil {
+		glog.Error(err)
+		return err
+	}
+	if err := exec.Command("ip", "addr", "add", wantCIDR.String(), "dev", "cbr0").Run(); err != nil {
+		glog.Error(err)
+		return err
+	}
+	if err := exec.Command("ip", "link", "set", "dev", "cbr0", "up").Run(); err != nil {
+		glog.Error(err)
+		return err
+	}
+	// restart docker
+	if err := exec.Command("service", "docker", "restart").Run(); err != nil {
+		glog.Error(err)
+		// For now just log the error. The containerRuntime check will catch docker failures.
+		// TODO (dawnchen) figure out what we should do for rkt here.
+	}
+	glog.V(2).Info("Recreated cbr0 and restarted docker")
+	return nil
+}
+
 func ensureCbr0(wantCIDR *net.IPNet) error {
-	if !cbr0CidrCorrect(wantCIDR) {
+	exists, err := cbr0Exists()
+	if err != nil {
+		return err
+	}
+	if !exists {
+		glog.V(2).Infof("CBR0 doesn't exist, attempting to create it with range: %s", wantCIDR)
+		return createCBR0(wantCIDR)
+	} else if !cbr0CidrCorrect(wantCIDR) {
 		glog.V(2).Infof("Attempting to recreate cbr0 with address range: %s", wantCIDR)
 
 		// delete cbr0
@@ -40,30 +72,22 @@ func ensureCbr0(wantCIDR *net.IPNet) error {
 			glog.Error(err)
 			return err
 		}
-		// recreate cbr0 with wantCIDR
-		if err := exec.Command("brctl", "addbr", "cbr0").Run(); err != nil {
-			glog.Error(err)
-			return err
-		}
-		if err := exec.Command("ip", "addr", "add", wantCIDR.String(), "dev", "cbr0").Run(); err != nil {
-			glog.Error(err)
-			return err
-		}
-		if err := exec.Command("ip", "link", "set", "dev", "cbr0", "up").Run(); err != nil {
-			glog.Error(err)
-			return err
-		}
-		// restart docker
-		if err := exec.Command("service", "docker", "restart").Run(); err != nil {
-			glog.Error(err)
-			// For now just log the error. The containerRuntime check will catch docker failures.
-			// TODO (dawnchen) figure out what we should do for rkt here.
-		}
-		glog.V(2).Info("Recreated cbr0 and restarted docker")
+		return createCBR0(wantCIDR)
 	}
 	return nil
 }
 
+func cbr0Exists() (bool, error) {
+	_, err := os.Stat("/sys/class/net/cbr0")
+	if err != nil {
+		if os.IsNotExist(err) {
+			return false, nil
+		}
+		return false, err
+	}
+	return true, nil
+}
+
 func cbr0CidrCorrect(wantCIDR *net.IPNet) bool {
 	output, err := exec.Command("ip", "addr", "show", "cbr0").Output()
 	if err != nil {

pkg/kubelet/kubelet.go

@@ -147,6 +147,7 @@ func NewMainKubelet(
 	dockerDaemonContainer string,
 	systemContainer string,
 	configureCBR0 bool,
+	podCIDR string,
 	pods int,
 	dockerExecHandler dockertools.ExecHandler) (*Kubelet, error) {
 	if rootDirectory == "" {
@@ -261,6 +262,7 @@ func NewMainKubelet(
 		cgroupRoot:                     cgroupRoot,
 		mounter:                        mounter,
 		configureCBR0:                  configureCBR0,
+		podCIDR:                        podCIDR,
 		pods:                           pods,
 		syncLoopMonitor:                util.AtomicValue{},
 	}
@@ -318,6 +320,10 @@ func NewMainKubelet(
 	}
 	klet.containerManager = containerManager
 
+	// Start syncing node status immediately, this may set up things the runtime needs to run.
+	go klet.syncNodeStatus()
+	go klet.syncNetworkStatus()
+
 	// Wait for the runtime to be up with a timeout.
 	if err := waitUntilRuntimeIsUp(klet.containerRuntime, maxWaitForContainerRuntime); err != nil {
 		return nil, fmt.Errorf("timed out waiting for %q to come up: %v", containerRuntime, err)
@@ -412,6 +418,9 @@ type Kubelet struct {
 	runtimeUpThreshold     time.Duration
 	lastTimestampRuntimeUp time.Time
 
+	// Network Status information
+	networkConfigured bool
+
 	// Volume plugins.
 	volumePluginMgr volume.VolumePluginMgr
 
@@ -489,6 +498,7 @@ type Kubelet struct {
 	// Whether or not kubelet should take responsibility for keeping cbr0 in
 	// the correct state.
 	configureCBR0 bool
+	podCIDR       string
 
 	// Number of Pods which can be run by this Kubelet
 	pods int
@@ -707,7 +717,6 @@ func (kl *Kubelet) Run(updates <-chan PodUpdate) {
 	}
 
 	go util.Until(kl.updateRuntimeUp, 5*time.Second, util.NeverStop)
-	go kl.syncNodeStatus()
 	// Run the system oom watcher forever.
 	kl.statusManager.Start()
 	kl.syncLoop(updates, kl)
@@ -1705,6 +1714,10 @@ func (kl *Kubelet) syncLoopIteration(updates <-chan PodUpdate, handler SyncHandl
 		glog.Infof("Skipping pod synchronization, container runtime is not up.")
 		return
 	}
+	if !kl.networkConfigured {
+		time.Sleep(5 * time.Second)
+		glog.Infof("Skipping pod synchronization, network is not configured")
+	}
 	unsyncedPod := false
 	podSyncTypes := make(map[types.UID]SyncPodType)
 	select {
@@ -1892,6 +1905,22 @@ func (kl *Kubelet) recordNodeStatusEvent(event string) {
 // Maintains Node.Spec.Unschedulable value from previous run of tryUpdateNodeStatus()
 var oldNodeUnschedulable bool
 
+func (kl *Kubelet) syncNetworkStatus() {
+	for {
+		networkConfigured := true
+		if kl.configureCBR0 {
+			if len(kl.podCIDR) == 0 {
+				networkConfigured = false
+			} else if err := kl.reconcileCBR0(kl.podCIDR); err != nil {
+				networkConfigured = false
+				glog.Errorf("Error configuring cbr0: %v", err)
+			}
+		}
+		kl.networkConfigured = networkConfigured
+		time.Sleep(30 * time.Second)
+	}
+}
+
 // setNodeStatus fills in the Status fields of the given Node, overwriting
 // any fields that are currently set.
 func (kl *Kubelet) setNodeStatus(node *api.Node) error {
@@ -1925,16 +1954,6 @@ func (kl *Kubelet) setNodeStatus(node *api.Node) error {
 		}
 	}
 
-	networkConfigured := true
-	if kl.configureCBR0 {
-		if len(node.Spec.PodCIDR) == 0 {
-			networkConfigured = false
-		} else if err := kl.reconcileCBR0(node.Spec.PodCIDR); err != nil {
-			networkConfigured = false
-			glog.Errorf("Error configuring cbr0: %v", err)
-		}
-	}
-
 	// TODO: Post NotReady if we cannot get MachineInfo from cAdvisor. This needs to start
 	// cAdvisor locally, e.g. for test-cmd.sh, and in integration test.
 	info, err := kl.GetCachedMachineInfo()
@@ -1982,7 +2001,7 @@ func (kl *Kubelet) setNodeStatus(node *api.Node) error {
 	currentTime := util.Now()
 	var newNodeReadyCondition api.NodeCondition
 	var oldNodeReadyConditionStatus api.ConditionStatus
-	if containerRuntimeUp && networkConfigured {
+	if containerRuntimeUp && kl.networkConfigured {
 		newNodeReadyCondition = api.NodeCondition{
 			Type:              api.NodeReady,
 			Status:            api.ConditionTrue,
@@ -1994,7 +2013,7 @@ func (kl *Kubelet) setNodeStatus(node *api.Node) error {
 		if !containerRuntimeUp {
 			reasons = append(reasons, "container runtime is down")
 		}
-		if !networkConfigured {
+		if !kl.networkConfigured {
 			reasons = append(reasons, "network not configured correctly")
 		}
 		newNodeReadyCondition = api.NodeCondition{
@@ -2056,6 +2075,8 @@ func (kl *Kubelet) tryUpdateNodeStatus() error {
 	if node == nil {
 		return fmt.Errorf("no node instance returned for %q", kl.nodeName)
 	}
+	kl.podCIDR = node.Spec.PodCIDR
+
 	if err := kl.setNodeStatus(node); err != nil {
 		return err
 	}

pkg/kubelet/status_manager.go

@@ -17,9 +17,11 @@ limitations under the License.
 package kubelet
 
 import (
+	"errors"
 	"fmt"
 	"reflect"
 	"sync"
+	"time"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/client"
@@ -58,6 +60,8 @@ func (s *statusManager) Start() {
 		err := s.syncBatch()
 		if err != nil {
 			glog.Warningf("Failed to updated pod status: %v", err)
+			// Errors and tight-looping are bad, m-kay
+			time.Sleep(30 * time.Second)
 		}
 	}, 0)
 }
@@ -124,6 +128,9 @@ func (s *statusManager) RemoveOrphanedStatuses(podFullNames map[string]bool) {
 
 // syncBatch syncs pods statuses with the apiserver.
 func (s *statusManager) syncBatch() error {
+	if s.kubeClient == nil {
+		return errors.New("Kubernetes client is nil, skipping pod status updates")
+	}
 	syncRequest := <-s.podStatusChannel
 	pod := syncRequest.pod
 	podFullName := kubecontainer.GetPodFullName(pod)