/* Copyright 2014 The Kubernetes Authors 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 // Note: if you change code in this file, you might need to change code in // contrib/mesos/pkg/executor/service/. 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/clientcmd" clientcmdapi "github.com/GoogleCloudPlatform/kubernetes/pkg/client/clientcmd/api" "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" kubecontainer "github.com/GoogleCloudPlatform/kubernetes/pkg/kubelet/container" "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/util/mount" nodeutil "github.com/GoogleCloudPlatform/kubernetes/pkg/util/node" "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 util.StringFlag // Deprecated -- use KubeConfig instead KubeConfig util.StringFlag CadvisorPort uint HealthzPort int HealthzBindAddress util.IP OOMScoreAdj int APIServerList util.StringList RegisterNode bool StandaloneMode bool ClusterDomain string MasterServiceNamespace string ClusterDNS util.IP StreamingConnectionIdleTimeout time.Duration ImageGCHighThresholdPercent int ImageGCLowThresholdPercent int LowDiskSpaceThresholdMB int NetworkPluginName string CloudProvider string CloudConfigFile string TLSCertFile string TLSPrivateKeyFile string CertDirectory string NodeStatusUpdateFrequency time.Duration ResourceContainer string CgroupRoot string ContainerRuntime string DockerDaemonContainer string SystemContainer string ConfigureCBR0 bool MaxPods int DockerExecHandlerName 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 // Is the kubelet containerized? Containerized bool } // 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: 2, MaxContainerCount: 100, AuthPath: util.NewStringFlag("/var/lib/kubelet/kubernetes_auth"), // deprecated KubeConfig: util.NewStringFlag("/var/lib/kubelet/kubeconfig"), CadvisorPort: 4194, HealthzPort: 10248, HealthzBindAddress: util.IP(net.ParseIP("127.0.0.1")), RegisterNode: true, // will be ignored if no apiserver is configured OOMScoreAdj: -900, MasterServiceNamespace: api.NamespaceDefault, ImageGCHighThresholdPercent: 90, ImageGCLowThresholdPercent: 80, LowDiskSpaceThresholdMB: 256, NetworkPluginName: "", HostNetworkSources: kubelet.FileSource, CertDirectory: "/var/run/kubernetes", NodeStatusUpdateFrequency: 10 * time.Second, ResourceContainer: "/kubelet", CgroupRoot: "", ContainerRuntime: "docker", DockerDaemonContainer: "/docker-daemon", SystemContainer: "", ConfigureCBR0: false, DockerExecHandlerName: "native", } } // 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 Kubelet's server") fs.Var(&s.Address, "address", "The IP address for the Kubelet to serve on (set to 0.0.0.0 for all interfaces)") fs.UintVar(&s.Port, "port", s.Port, "The port for the Kubelet to serve on. Note that \"kubectl logs\" will not work if you set this flag.") // see #9325 fs.UintVar(&s.ReadOnlyPort, "read-only-port", s.ReadOnlyPort, "The read-only port for the Kubelet 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). "+ "If --tls_cert_file and --tls_private_key_file are provided, this flag will be ignored.") 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: 2.") 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.Var(&s.AuthPath, "auth-path", "Path to .kubernetes_auth file, specifying how to authenticate to API server.") fs.MarkDeprecated("auth-path", "will be removed in a future version") fs.Var(&s.KubeConfig, "kubeconfig", "Path to a kubeconfig file, specifying how to authenticate to API server (the master location is set by the api-servers flag).") 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.BoolVar(&s.RegisterNode, "register-node", s.RegisterNode, "Register the node with the apiserver (defaults to true if --api-server is set)") 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.IntVar(&s.LowDiskSpaceThresholdMB, "low-diskspace-threshold-mb", s.LowDiskSpaceThresholdMB, "The absolute free disk space, in MB, to maintain. When disk space falls below this threshold, new pods would be rejected. Default: 256") 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).") 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.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.") 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'.") // 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]") fs.BoolVar(&s.Containerized, "containerized", s.Containerized, "Experimental support for running kubelet in a container. Intended for testing. [default=false]") } // 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.Warning(err) } var apiclient *client.Client clientConfig, err := s.CreateAPIServerClientConfig() if err == nil { apiclient, err = client.New(clientConfig) } if err != nil && len(s.APIServerList) > 0 { glog.Warningf("No API client: %v", err) } glog.V(2).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, } diskSpacePolicy := kubelet.DiskSpacePolicy{ DockerFreeDiskMB: s.LowDiskSpaceThresholdMB, RootFreeDiskMB: s.LowDiskSpaceThresholdMB, } cloud := cloudprovider.InitCloudProvider(s.CloudProvider, s.CloudConfigFile) glog.V(2).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 } tlsOptions, err := s.InitializeTLS() if err != nil { return err } mounter := mount.New() if s.Containerized { glog.V(2).Info("Running kubelet in containerized mode (experimental)") mounter = &mount.NsenterMounter{} } var dockerExecHandler dockertools.ExecHandler switch s.DockerExecHandlerName { case "native": dockerExecHandler = &dockertools.NativeExecHandler{} case "nsenter": dockerExecHandler = &dockertools.NsenterExecHandler{} default: glog.Warningf("Unknown Docker exec handler %q; defaulting to native", s.DockerExecHandlerName) dockerExecHandler = &dockertools.NativeExecHandler{} } 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, RegisterNode: s.RegisterNode, StandaloneMode: (len(s.APIServerList) == 0), 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: apiclient, MasterServiceNamespace: s.MasterServiceNamespace, VolumePlugins: ProbeVolumePlugins(), NetworkPlugins: ProbeNetworkPlugins(), NetworkPluginName: s.NetworkPluginName, StreamingConnectionIdleTimeout: s.StreamingConnectionIdleTimeout, TLSOptions: tlsOptions, ImageGCPolicy: imageGCPolicy, DiskSpacePolicy: diskSpacePolicy, Cloud: cloud, NodeStatusUpdateFrequency: s.NodeStatusUpdateFrequency, ResourceContainer: s.ResourceContainer, CgroupRoot: s.CgroupRoot, ContainerRuntime: s.ContainerRuntime, Mounter: mounter, DockerDaemonContainer: s.DockerDaemonContainer, SystemContainer: s.SystemContainer, ConfigureCBR0: s.ConfigureCBR0, MaxPods: s.MaxPods, DockerExecHandler: dockerExecHandler, } if err := RunKubelet(&kcfg, nil); err != nil { return err } 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) } if s.RunOnce { return nil } // run forever select {} } // InitializeTLS checks for a configured TLSCertFile and TLSPrivateKeyFile: if unspecified a new self-signed // certificate and key file are generated. Returns a configured kubelet.TLSOptions object. func (s *KubeletServer) InitializeTLS() (*kubelet.TLSOptions, error) { 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(nodeutil.GetHostname(s.HostnameOverride), s.TLSCertFile, s.TLSPrivateKeyFile); err != nil { return nil, fmt.Errorf("unable to generate self signed cert: %v", err) } glog.V(4).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, } return tlsOptions, nil } func (s *KubeletServer) authPathClientConfig(useDefaults bool) (*client.Config, error) { authInfo, err := clientauth.LoadFromFile(s.AuthPath.Value()) if err != nil && !useDefaults { return nil, err } // If loading the default auth path, for backwards compatibility keep going // with the default auth. if err != nil { glog.Warningf("Could not load kubernetes auth path %s: %v. Continuing with defaults.", s.AuthPath, err) } if authInfo == nil { // authInfo didn't load correctly - continue with defaults. authInfo = &clientauth.Info{} } authConfig, err := authInfo.MergeWithConfig(client.Config{}) if err != nil { return nil, err } authConfig.Host = s.APIServerList[0] return &authConfig, nil } func (s *KubeletServer) kubeconfigClientConfig() (*client.Config, error) { return clientcmd.NewNonInteractiveDeferredLoadingClientConfig( &clientcmd.ClientConfigLoadingRules{ExplicitPath: s.KubeConfig.Value()}, &clientcmd.ConfigOverrides{ClusterInfo: clientcmdapi.Cluster{Server: s.APIServerList[0]}}).ClientConfig() } // createClientConfig creates a client configuration from the command line // arguments. If either --auth-path or --kubeconfig is explicitly set, it // will be used (setting both is an error). If neither are set first attempt // to load the default kubeconfig file, then the default auth path file, and // fall back to the default auth (none) without an error. // TODO(roberthbailey): Remove support for --auth-path func (s *KubeletServer) createClientConfig() (*client.Config, error) { if s.KubeConfig.Provided() && s.AuthPath.Provided() { return nil, fmt.Errorf("cannot specify both --kubeconfig and --auth-path") } if s.KubeConfig.Provided() { return s.kubeconfigClientConfig() } else if s.AuthPath.Provided() { return s.authPathClientConfig(false) } // Try the kubeconfig default first, falling back to the auth path default. clientConfig, err := s.kubeconfigClientConfig() if err != nil { glog.Warningf("Could not load kubeconfig file %s: %v. Trying auth path instead.", s.KubeConfig, err) return s.authPathClientConfig(true) } return clientConfig, nil } // CreateAPIServerClientConfig generates a client.Config from command line flags, // including api-server-list, via createClientConfig and then injects chaos into // the configuration via addChaosToClientConfig. This func is exported to support // integration with third party kubelet extensions (e.g. kubernetes-mesos). func (s *KubeletServer) CreateAPIServerClientConfig() (*client.Config, error) { 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, err := s.createClientConfig() if err != nil { return nil, err } s.addChaosToClientConfig(clientConfig) return clientConfig, 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, osInterface kubecontainer.OSInterface) *KubeletConfig { imageGCPolicy := kubelet.ImageGCPolicy{ HighThresholdPercent: 90, LowThresholdPercent: 80, } diskSpacePolicy := kubelet.DiskSpacePolicy{ DockerFreeDiskMB: 256, RootFreeDiskMB: 256, } 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: 2, MaxContainerCount: 100, RegisterNode: true, MasterServiceNamespace: masterServiceNamespace, VolumePlugins: volumePlugins, TLSOptions: tlsOptions, CadvisorInterface: cadvisorInterface, ConfigFile: configFilePath, ImageGCPolicy: imageGCPolicy, DiskSpacePolicy: diskSpacePolicy, Cloud: cloud, NodeStatusUpdateFrequency: 10 * time.Second, ResourceContainer: "/kubelet", OSInterface: osInterface, CgroupRoot: "", ContainerRuntime: "docker", Mounter: mount.New(), DockerDaemonContainer: "/docker-daemon", SystemContainer: "", MaxPods: 32, DockerExecHandler: &dockertools.NativeExecHandler{}, } 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) error { kcfg.Hostname = nodeutil.GetHostname(kcfg.HostnameOverride) if kcfg.NodeName == "" { // Query the cloud provider for our node name, default to Hostname nodeName := kcfg.Hostname if kcfg.Cloud != nil { var err error instances, ok := kcfg.Cloud.Instances() if !ok { return fmt.Errorf("failed to get instances from cloud provider") } nodeName, err = instances.CurrentNodeName(kcfg.Hostname) if err != nil { return fmt.Errorf("error fetching current instance name from cloud provider: %v", err) } glog.V(2).Infof("cloud provider determined current node name to be %s", nodeName) } kcfg.NodeName = nodeName } eventBroadcaster := record.NewBroadcaster() kcfg.Recorder = eventBroadcaster.NewRecorder(api.EventSource{Component: "kubelet", Host: kcfg.NodeName}) eventBroadcaster.StartLogging(glog.Infof) if kcfg.KubeClient != nil { glog.V(4).Infof("Sending events to api server.") eventBroadcaster.StartRecordingToSink(kcfg.KubeClient.Events("")) } else { glog.Warning("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 } if kcfg.OSInterface == nil { kcfg.OSInterface = kubecontainer.RealOS{} } k, podCfg, err := builder(kcfg) if err != nil { return fmt.Errorf("failed to create kubelet: %v", err) } // process pods and exit. if kcfg.Runonce { if _, err := k.RunOnce(podCfg.Updates()); err != nil { return fmt.Errorf("runonce failed: %v", err) } glog.Infof("Started kubelet as runonce") } else { startKubelet(k, podCfg, kcfg) glog.Infof("Started kubelet") } return nil } 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.NodeName, 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.NodeName, kc.HTTPCheckFrequency, cfg.Channel(kubelet.HTTPSource)) } if kc.KubeClient != nil { glog.Infof("Watching apiserver") config.NewSourceApiserver(kc.KubeClient, kc.NodeName, 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 NodeName string PodInfraContainerImage string SyncFrequency time.Duration RegistryPullQPS float64 RegistryBurst int MinimumGCAge time.Duration MaxPerPodContainerCount int MaxContainerCount int RegisterNode bool StandaloneMode bool 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 DiskSpacePolicy kubelet.DiskSpacePolicy Cloud cloudprovider.Interface NodeStatusUpdateFrequency time.Duration ResourceContainer string OSInterface kubecontainer.OSInterface CgroupRoot string ContainerRuntime string Mounter mount.Interface DockerDaemonContainer string SystemContainer string ConfigureCBR0 bool MaxPods int DockerExecHandler dockertools.ExecHandler } 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.NodeName, kc.DockerClient, kubeClient, kc.RootDirectory, kc.PodInfraContainerImage, kc.SyncFrequency, float32(kc.RegistryPullQPS), kc.RegistryBurst, gcPolicy, pc.SeenAllSources, kc.RegisterNode, kc.StandaloneMode, kc.ClusterDomain, net.IP(kc.ClusterDNS), kc.MasterServiceNamespace, kc.VolumePlugins, kc.NetworkPlugins, kc.NetworkPluginName, kc.StreamingConnectionIdleTimeout, kc.Recorder, kc.CadvisorInterface, kc.ImageGCPolicy, kc.DiskSpacePolicy, kc.Cloud, kc.NodeStatusUpdateFrequency, kc.ResourceContainer, kc.OSInterface, kc.CgroupRoot, kc.ContainerRuntime, kc.Mounter, kc.DockerDaemonContainer, kc.SystemContainer, kc.ConfigureCBR0, kc.MaxPods, kc.DockerExecHandler) if err != nil { return nil, nil, err } k.BirthCry() k.StartGarbageCollection() return k, pc, nil }