/* Copyright 2014 Google Inc. All rights reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ // Package app makes it easy to create a kubelet server for various contexts. package app import ( "crypto/tls" "fmt" "math/rand" "net" "net/http" _ "net/http/pprof" "path" "strconv" "strings" "time" "github.com/GoogleCloudPlatform/kubernetes/pkg/api" "github.com/GoogleCloudPlatform/kubernetes/pkg/capabilities" "github.com/GoogleCloudPlatform/kubernetes/pkg/client" "github.com/GoogleCloudPlatform/kubernetes/pkg/client/chaosclient" "github.com/GoogleCloudPlatform/kubernetes/pkg/client/record" "github.com/GoogleCloudPlatform/kubernetes/pkg/clientauth" "github.com/GoogleCloudPlatform/kubernetes/pkg/credentialprovider" "github.com/GoogleCloudPlatform/kubernetes/pkg/healthz" "github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet" "github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/cadvisor" "github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/config" "github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/dockertools" "github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/network" "github.com/GoogleCloudPlatform/kubernetes/pkg/master/ports" "github.com/GoogleCloudPlatform/kubernetes/pkg/util" "github.com/GoogleCloudPlatform/kubernetes/pkg/volume" "github.com/GoogleCloudPlatform/kubernetes/pkg/cloudprovider" "github.com/golang/glog" "github.com/spf13/pflag" ) const defaultRootDir = "/var/lib/kubelet" // KubeletServer encapsulates all of the parameters necessary for starting up // a kubelet. These can either be set via command line or directly. type KubeletServer struct { Config string SyncFrequency time.Duration FileCheckFrequency time.Duration HTTPCheckFrequency time.Duration ManifestURL string EnableServer bool Address util.IP Port uint ReadOnlyPort uint HostnameOverride string PodInfraContainerImage string DockerEndpoint string RootDirectory string AllowPrivileged bool HostNetworkSources string RegistryPullQPS float64 RegistryBurst int RunOnce bool EnableDebuggingHandlers bool MinimumGCAge time.Duration MaxPerPodContainerCount int MaxContainerCount int AuthPath string CadvisorPort uint HealthzPort int HealthzBindAddress util.IP OOMScoreAdj int APIServerList util.StringList ClusterDomain string MasterServiceNamespace string ClusterDNS util.IP StreamingConnectionIdleTimeout time.Duration ImageGCHighThresholdPercent int ImageGCLowThresholdPercent int NetworkPluginName string CloudProvider string CloudConfigFile string TLSCertFile string TLSPrivateKeyFile string CertDirectory string NodeStatusUpdateFrequency time.Duration ResourceContainer string // Flags intended for testing // Crash immediately, rather than eating panics. ReallyCrashForTesting bool // Insert a probability of random errors during calls to the master. ChaosChance float64 } // bootstrapping interface for kubelet, targets the initialization protocol type KubeletBootstrap interface { BirthCry() StartGarbageCollection() ListenAndServe(net.IP, uint, *kubelet.TLSOptions, bool) ListenAndServeReadOnly(net.IP, uint) Run(<-chan kubelet.PodUpdate) RunOnce(<-chan kubelet.PodUpdate) ([]kubelet.RunPodResult, error) } // create and initialize a Kubelet instance type KubeletBuilder func(kc *KubeletConfig) (KubeletBootstrap, *config.PodConfig, error) // NewKubeletServer will create a new KubeletServer with default values. func NewKubeletServer() *KubeletServer { return &KubeletServer{ SyncFrequency: 10 * time.Second, FileCheckFrequency: 20 * time.Second, HTTPCheckFrequency: 20 * time.Second, EnableServer: true, Address: util.IP(net.ParseIP("0.0.0.0")), Port: ports.KubeletPort, ReadOnlyPort: ports.KubeletReadOnlyPort, PodInfraContainerImage: dockertools.PodInfraContainerImage, RootDirectory: defaultRootDir, RegistryBurst: 10, EnableDebuggingHandlers: true, MinimumGCAge: 1 * time.Minute, MaxPerPodContainerCount: 5, MaxContainerCount: 100, AuthPath: "/var/lib/kubelet/kubernetes_auth", CadvisorPort: 4194, HealthzPort: 10248, HealthzBindAddress: util.IP(net.ParseIP("127.0.0.1")), OOMScoreAdj: -900, MasterServiceNamespace: api.NamespaceDefault, ImageGCHighThresholdPercent: 90, ImageGCLowThresholdPercent: 80, NetworkPluginName: "", HostNetworkSources: kubelet.FileSource, CertDirectory: "/var/run/kubernetes", NodeStatusUpdateFrequency: 10 * time.Second, ResourceContainer: "/kubelet", } } // AddFlags adds flags for a specific KubeletServer to the specified FlagSet func (s *KubeletServer) AddFlags(fs *pflag.FlagSet) { fs.StringVar(&s.Config, "config", s.Config, "Path to the config file or directory of files") fs.DurationVar(&s.SyncFrequency, "sync_frequency", s.SyncFrequency, "Max period between synchronizing running containers and config") fs.DurationVar(&s.FileCheckFrequency, "file_check_frequency", s.FileCheckFrequency, "Duration between checking config files for new data") fs.DurationVar(&s.HTTPCheckFrequency, "http_check_frequency", s.HTTPCheckFrequency, "Duration between checking http for new data") fs.StringVar(&s.ManifestURL, "manifest_url", s.ManifestURL, "URL for accessing the container manifest") fs.BoolVar(&s.EnableServer, "enable_server", s.EnableServer, "Enable the info server") fs.Var(&s.Address, "address", "The IP address for the info server to serve on (set to 0.0.0.0 for all interfaces)") fs.UintVar(&s.Port, "port", s.Port, "The port for the info server to serve on") fs.UintVar(&s.ReadOnlyPort, "read_only_port", s.ReadOnlyPort, "The read-only port for the info server to serve on (set to 0 to disable)") fs.StringVar(&s.TLSCertFile, "tls_cert_file", s.TLSCertFile, ""+ "File containing x509 Certificate for HTTPS. (CA cert, if any, concatenated after server cert). "+ "If --tls_cert_file and --tls_private_key_file are not provided, a self-signed certificate and key "+ "are generated for the public address and saved to the directory passed to --cert_dir.") fs.StringVar(&s.TLSPrivateKeyFile, "tls_private_key_file", s.TLSPrivateKeyFile, "File containing x509 private key matching --tls_cert_file.") fs.StringVar(&s.CertDirectory, "cert_dir", s.CertDirectory, "The directory where the TLS certs are located (by default /var/run/kubernetes)") fs.StringVar(&s.HostnameOverride, "hostname_override", s.HostnameOverride, "If non-empty, will use this string as identification instead of the actual hostname.") fs.StringVar(&s.PodInfraContainerImage, "pod_infra_container_image", s.PodInfraContainerImage, "The image whose network/ipc namespaces containers in each pod will use.") fs.StringVar(&s.DockerEndpoint, "docker_endpoint", s.DockerEndpoint, "If non-empty, use this for the docker endpoint to communicate with") fs.StringVar(&s.RootDirectory, "root_dir", s.RootDirectory, "Directory path for managing kubelet files (volume mounts,etc).") fs.BoolVar(&s.AllowPrivileged, "allow_privileged", s.AllowPrivileged, "If true, allow containers to request privileged mode. [default=false]") fs.StringVar(&s.HostNetworkSources, "host_network_sources", s.HostNetworkSources, "Comma-separated list of sources from which the Kubelet allows pods to use of host network. For all sources use \"*\" [default=\"file\"]") fs.Float64Var(&s.RegistryPullQPS, "registry_qps", s.RegistryPullQPS, "If > 0, limit registry pull QPS to this value. If 0, unlimited. [default=0.0]") fs.IntVar(&s.RegistryBurst, "registry_burst", s.RegistryBurst, "Maximum size of a bursty pulls, temporarily allows pulls to burst to this number, while still not exceeding registry_qps. Only used if --registry_qps > 0") fs.BoolVar(&s.RunOnce, "runonce", s.RunOnce, "If true, exit after spawning pods from local manifests or remote urls. Exclusive with --api_servers, and --enable-server") fs.BoolVar(&s.EnableDebuggingHandlers, "enable_debugging_handlers", s.EnableDebuggingHandlers, "Enables server endpoints for log collection and local running of containers and commands") fs.DurationVar(&s.MinimumGCAge, "minimum_container_ttl_duration", s.MinimumGCAge, "Minimum age for a finished container before it is garbage collected. Examples: '300ms', '10s' or '2h45m'") fs.IntVar(&s.MaxPerPodContainerCount, "maximum_dead_containers_per_container", s.MaxPerPodContainerCount, "Maximum number of old instances of a container to retain per container. Each container takes up some disk space. Default: 5.") fs.IntVar(&s.MaxContainerCount, "maximum_dead_containers", s.MaxContainerCount, "Maximum number of old instances of a containers to retain globally. Each container takes up some disk space. Default: 100.") fs.StringVar(&s.AuthPath, "auth_path", s.AuthPath, "Path to .kubernetes_auth file, specifying how to authenticate to API server.") fs.UintVar(&s.CadvisorPort, "cadvisor_port", s.CadvisorPort, "The port of the localhost cAdvisor endpoint") fs.IntVar(&s.HealthzPort, "healthz_port", s.HealthzPort, "The port of the localhost healthz endpoint") fs.Var(&s.HealthzBindAddress, "healthz_bind_address", "The IP address for the healthz server to serve on, defaulting to 127.0.0.1 (set to 0.0.0.0 for all interfaces)") fs.IntVar(&s.OOMScoreAdj, "oom_score_adj", s.OOMScoreAdj, "The oom_score_adj value for kubelet process. Values must be within the range [-1000, 1000]") fs.Var(&s.APIServerList, "api_servers", "List of Kubernetes API servers for publishing events, and reading pods and services. (ip:port), comma separated.") fs.StringVar(&s.ClusterDomain, "cluster_domain", s.ClusterDomain, "Domain for this cluster. If set, kubelet will configure all containers to search this domain in addition to the host's search domains") fs.StringVar(&s.MasterServiceNamespace, "master_service_namespace", s.MasterServiceNamespace, "The namespace from which the kubernetes master services should be injected into pods") fs.Var(&s.ClusterDNS, "cluster_dns", "IP address for a cluster DNS server. If set, kubelet will configure all containers to use this for DNS resolution in addition to the host's DNS servers") fs.DurationVar(&s.StreamingConnectionIdleTimeout, "streaming_connection_idle_timeout", 0, "Maximum time a streaming connection can be idle before the connection is automatically closed. Example: '5m'") fs.DurationVar(&s.NodeStatusUpdateFrequency, "node_status_update_frequency", s.NodeStatusUpdateFrequency, "Specifies how often kubelet posts node status to master. Note: be cautious when changing the constant, it must work with nodeMonitorGracePeriod in nodecontroller. Default: 10s") fs.IntVar(&s.ImageGCHighThresholdPercent, "image_gc_high_threshold", s.ImageGCHighThresholdPercent, "The percent of disk usage after which image garbage collection is always run. Default: 90%%") fs.IntVar(&s.ImageGCLowThresholdPercent, "image_gc_low_threshold", s.ImageGCLowThresholdPercent, "The percent of disk usage before which image garbage collection is never run. Lowest disk usage to garbage collect to. Default: 80%%") fs.StringVar(&s.NetworkPluginName, "network_plugin", s.NetworkPluginName, " The name of the network plugin to be invoked for various events in kubelet/pod lifecycle") fs.StringVar(&s.CloudProvider, "cloud_provider", s.CloudProvider, "The provider for cloud services. Empty string for no provider.") fs.StringVar(&s.CloudConfigFile, "cloud_config", s.CloudConfigFile, "The path to the cloud provider configuration file. Empty string for no configuration file.") fs.StringVar(&s.ResourceContainer, "resource_container", s.ResourceContainer, "Absolute name of the resource-only container to create and run the Kubelet in (Default: /kubelet).") // 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]") } // Run runs the specified KubeletServer. This should never exit. func (s *KubeletServer) Run(_ []string) error { util.ReallyCrash = s.ReallyCrashForTesting rand.Seed(time.Now().UTC().UnixNano()) // TODO(vmarmol): Do this through container config. if err := util.ApplyOomScoreAdj(0, s.OOMScoreAdj); err != nil { glog.Info(err) } client, err := s.createAPIServerClient() if err != nil && len(s.APIServerList) > 0 { glog.Warningf("No API client: %v", err) } glog.Infof("Using root directory: %v", s.RootDirectory) credentialprovider.SetPreferredDockercfgPath(s.RootDirectory) cadvisorInterface, err := cadvisor.New(s.CadvisorPort) if err != nil { return err } imageGCPolicy := kubelet.ImageGCPolicy{ HighThresholdPercent: s.ImageGCHighThresholdPercent, LowThresholdPercent: s.ImageGCLowThresholdPercent, } cloud := cloudprovider.InitCloudProvider(s.CloudProvider, s.CloudConfigFile) glog.Infof("Successfully initialized cloud provider: %q from the config file: %q\n", s.CloudProvider, s.CloudConfigFile) hostNetworkSources, err := kubelet.GetValidatedSources(strings.Split(s.HostNetworkSources, ",")) if err != nil { return err } if s.TLSCertFile == "" && s.TLSPrivateKeyFile == "" { s.TLSCertFile = path.Join(s.CertDirectory, "kubelet.crt") s.TLSPrivateKeyFile = path.Join(s.CertDirectory, "kubelet.key") if err := util.GenerateSelfSignedCert(util.GetHostname(s.HostnameOverride), s.TLSCertFile, s.TLSPrivateKeyFile); err != nil { glog.Fatalf("Unable to generate self signed cert: %v", err) } glog.Infof("Using self-signed cert (%s, %s)", s.TLSCertFile, s.TLSPrivateKeyFile) } tlsOptions := &kubelet.TLSOptions{ Config: &tls.Config{ // Change default from SSLv3 to TLSv1.0 (because of POODLE vulnerability). MinVersion: tls.VersionTLS10, // Populate PeerCertificates in requests, but don't yet reject connections without certificates. ClientAuth: tls.RequestClientCert, }, CertFile: s.TLSCertFile, KeyFile: s.TLSPrivateKeyFile, } kcfg := KubeletConfig{ Address: s.Address, AllowPrivileged: s.AllowPrivileged, HostNetworkSources: hostNetworkSources, HostnameOverride: s.HostnameOverride, RootDirectory: s.RootDirectory, ConfigFile: s.Config, ManifestURL: s.ManifestURL, FileCheckFrequency: s.FileCheckFrequency, HTTPCheckFrequency: s.HTTPCheckFrequency, PodInfraContainerImage: s.PodInfraContainerImage, SyncFrequency: s.SyncFrequency, RegistryPullQPS: s.RegistryPullQPS, RegistryBurst: s.RegistryBurst, MinimumGCAge: s.MinimumGCAge, MaxPerPodContainerCount: s.MaxPerPodContainerCount, MaxContainerCount: s.MaxContainerCount, ClusterDomain: s.ClusterDomain, ClusterDNS: s.ClusterDNS, Runonce: s.RunOnce, Port: s.Port, ReadOnlyPort: s.ReadOnlyPort, CadvisorInterface: cadvisorInterface, EnableServer: s.EnableServer, EnableDebuggingHandlers: s.EnableDebuggingHandlers, DockerClient: dockertools.ConnectToDockerOrDie(s.DockerEndpoint), KubeClient: client, MasterServiceNamespace: s.MasterServiceNamespace, VolumePlugins: ProbeVolumePlugins(), NetworkPlugins: ProbeNetworkPlugins(), NetworkPluginName: s.NetworkPluginName, StreamingConnectionIdleTimeout: s.StreamingConnectionIdleTimeout, TLSOptions: tlsOptions, ImageGCPolicy: imageGCPolicy, Cloud: cloud, NodeStatusUpdateFrequency: s.NodeStatusUpdateFrequency, ResourceContainer: s.ResourceContainer, } RunKubelet(&kcfg, nil) if s.HealthzPort > 0 { healthz.DefaultHealthz() go util.Forever(func() { err := http.ListenAndServe(net.JoinHostPort(s.HealthzBindAddress.String(), strconv.Itoa(s.HealthzPort)), nil) if err != nil { glog.Errorf("Starting health server failed: %v", err) } }, 5*time.Second) } // runs forever select {} } // TODO: replace this with clientcmd func (s *KubeletServer) createAPIServerClient() (*client.Client, error) { authInfo, err := clientauth.LoadFromFile(s.AuthPath) if err != nil { glog.Warningf("Could not load kubernetes auth path: %v. Continuing with defaults.", err) } if authInfo == nil { // authInfo didn't load correctly - continue with defaults. authInfo = &clientauth.Info{} } clientConfig, err := authInfo.MergeWithConfig(client.Config{}) if err != nil { return nil, err } if len(s.APIServerList) < 1 { return nil, fmt.Errorf("no api servers specified") } // TODO: adapt Kube client to support LB over several servers if len(s.APIServerList) > 1 { glog.Infof("Multiple api servers specified. Picking first one") } clientConfig.Host = s.APIServerList[0] s.addChaosToClientConfig(&clientConfig) c, err := client.New(&clientConfig) if err != nil { return nil, err } return c, nil } // addChaosToClientConfig injects random errors into client connections if configured. func (s *KubeletServer) addChaosToClientConfig(config *client.Config) { if s.ChaosChance != 0.0 { config.WrapTransport = func(rt http.RoundTripper) http.RoundTripper { seed := chaosclient.NewSeed(1) // TODO: introduce a standard chaos package with more tunables - this is just a proof of concept // TODO: introduce random latency and stalls return chaosclient.NewChaosRoundTripper(rt, chaosclient.LogChaos, seed.P(s.ChaosChance, chaosclient.ErrSimulatedConnectionResetByPeer)) } } } // SimpleRunKubelet is a simple way to start a Kubelet talking to dockerEndpoint, using an API Client. // Under the hood it calls RunKubelet (below) func SimpleKubelet(client *client.Client, dockerClient dockertools.DockerInterface, hostname, rootDir, manifestURL, address string, port uint, masterServiceNamespace string, volumePlugins []volume.VolumePlugin, tlsOptions *kubelet.TLSOptions, cadvisorInterface cadvisor.Interface, configFilePath string, cloud cloudprovider.Interface) *KubeletConfig { imageGCPolicy := kubelet.ImageGCPolicy{ HighThresholdPercent: 90, LowThresholdPercent: 80, } kcfg := KubeletConfig{ KubeClient: client, DockerClient: dockerClient, HostnameOverride: hostname, RootDirectory: rootDir, ManifestURL: manifestURL, PodInfraContainerImage: dockertools.PodInfraContainerImage, Port: port, Address: util.IP(net.ParseIP(address)), EnableServer: true, EnableDebuggingHandlers: true, HTTPCheckFrequency: 1 * time.Second, FileCheckFrequency: 1 * time.Second, SyncFrequency: 3 * time.Second, MinimumGCAge: 10 * time.Second, MaxPerPodContainerCount: 5, MaxContainerCount: 100, MasterServiceNamespace: masterServiceNamespace, VolumePlugins: volumePlugins, TLSOptions: tlsOptions, CadvisorInterface: cadvisorInterface, ConfigFile: configFilePath, ImageGCPolicy: imageGCPolicy, Cloud: cloud, NodeStatusUpdateFrequency: 10 * time.Second, ResourceContainer: "/kubelet", } return &kcfg } // RunKubelet is responsible for setting up and running a kubelet. It is used in three different applications: // 1 Integration tests // 2 Kubelet binary // 3 Standalone 'kubernetes' binary // Eventually, #2 will be replaced with instances of #3 func RunKubelet(kcfg *KubeletConfig, builder KubeletBuilder) { kcfg.Hostname = util.GetHostname(kcfg.HostnameOverride) eventBroadcaster := record.NewBroadcaster() kcfg.Recorder = eventBroadcaster.NewRecorder(api.EventSource{Component: "kubelet", Host: kcfg.Hostname}) eventBroadcaster.StartLogging(glog.Infof) if kcfg.KubeClient != nil { glog.Infof("Sending events to api server.") eventBroadcaster.StartRecordingToSink(kcfg.KubeClient.Events("")) } else { glog.Infof("No api server defined - no events will be sent to API server.") } capabilities.Setup(kcfg.AllowPrivileged, kcfg.HostNetworkSources) credentialprovider.SetPreferredDockercfgPath(kcfg.RootDirectory) if builder == nil { builder = createAndInitKubelet } k, podCfg, err := builder(kcfg) if err != nil { glog.Errorf("Failed to create kubelet: %s", err) return } // process pods and exit. if kcfg.Runonce { if _, err := k.RunOnce(podCfg.Updates()); err != nil { glog.Errorf("--runonce failed: %v", err) } } else { startKubelet(k, podCfg, kcfg) } glog.Infof("Started kubelet") } func startKubelet(k KubeletBootstrap, podCfg *config.PodConfig, kc *KubeletConfig) { // start the kubelet go util.Forever(func() { k.Run(podCfg.Updates()) }, 0) // start the kubelet server if kc.EnableServer { go util.Forever(func() { k.ListenAndServe(net.IP(kc.Address), kc.Port, kc.TLSOptions, kc.EnableDebuggingHandlers) }, 0) } if kc.ReadOnlyPort > 0 { go util.Forever(func() { k.ListenAndServeReadOnly(net.IP(kc.Address), kc.ReadOnlyPort) }, 0) } } func makePodSourceConfig(kc *KubeletConfig) *config.PodConfig { // source of all configuration cfg := config.NewPodConfig(config.PodConfigNotificationSnapshotAndUpdates, kc.Recorder) // define file config source if kc.ConfigFile != "" { glog.Infof("Adding manifest file: %v", kc.ConfigFile) config.NewSourceFile(kc.ConfigFile, kc.Hostname, kc.FileCheckFrequency, cfg.Channel(kubelet.FileSource)) } // define url config source if kc.ManifestURL != "" { glog.Infof("Adding manifest url: %v", kc.ManifestURL) config.NewSourceURL(kc.ManifestURL, kc.Hostname, kc.HTTPCheckFrequency, cfg.Channel(kubelet.HTTPSource)) } if kc.KubeClient != nil { glog.Infof("Watching apiserver") config.NewSourceApiserver(kc.KubeClient, kc.Hostname, cfg.Channel(kubelet.ApiserverSource)) } return cfg } // KubeletConfig is all of the parameters necessary for running a kubelet. // TODO: This should probably be merged with KubeletServer. The extra object is a consequence of refactoring. type KubeletConfig struct { KubeClient *client.Client DockerClient dockertools.DockerInterface CadvisorInterface cadvisor.Interface Address util.IP AllowPrivileged bool HostNetworkSources []string HostnameOverride string RootDirectory string ConfigFile string ManifestURL string FileCheckFrequency time.Duration HTTPCheckFrequency time.Duration Hostname string PodInfraContainerImage string SyncFrequency time.Duration RegistryPullQPS float64 RegistryBurst int MinimumGCAge time.Duration MaxPerPodContainerCount int MaxContainerCount int ClusterDomain string ClusterDNS util.IP EnableServer bool EnableDebuggingHandlers bool Port uint ReadOnlyPort uint Runonce bool MasterServiceNamespace string VolumePlugins []volume.VolumePlugin NetworkPlugins []network.NetworkPlugin NetworkPluginName string StreamingConnectionIdleTimeout time.Duration Recorder record.EventRecorder TLSOptions *kubelet.TLSOptions ImageGCPolicy kubelet.ImageGCPolicy Cloud cloudprovider.Interface NodeStatusUpdateFrequency time.Duration ResourceContainer string } func createAndInitKubelet(kc *KubeletConfig) (k KubeletBootstrap, pc *config.PodConfig, err error) { // TODO: block until all sources have delivered at least one update to the channel, or break the sync loop // up into "per source" synchronizations // TODO: KubeletConfig.KubeClient should be a client interface, but client interface misses certain methods // used by kubelet. Since NewMainKubelet expects a client interface, we need to make sure we are not passing // a nil pointer to it when what we really want is a nil interface. var kubeClient client.Interface if kc.KubeClient != nil { kubeClient = kc.KubeClient } gcPolicy := kubelet.ContainerGCPolicy{ MinAge: kc.MinimumGCAge, MaxPerPodContainer: kc.MaxPerPodContainerCount, MaxContainers: kc.MaxContainerCount, } pc = makePodSourceConfig(kc) k, err = kubelet.NewMainKubelet( kc.Hostname, kc.DockerClient, kubeClient, kc.RootDirectory, kc.PodInfraContainerImage, kc.SyncFrequency, float32(kc.RegistryPullQPS), kc.RegistryBurst, gcPolicy, pc.SeenAllSources, kc.ClusterDomain, net.IP(kc.ClusterDNS), kc.MasterServiceNamespace, kc.VolumePlugins, kc.NetworkPlugins, kc.NetworkPluginName, kc.StreamingConnectionIdleTimeout, kc.Recorder, kc.CadvisorInterface, kc.ImageGCPolicy, kc.Cloud, kc.NodeStatusUpdateFrequency, kc.ResourceContainer) if err != nil { return nil, nil, err } k.BirthCry() k.StartGarbageCollection() return k, pc, nil }