/* Copyright 2015 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" "k8s.io/kubernetes/pkg/api" "k8s.io/kubernetes/pkg/capabilities" "k8s.io/kubernetes/pkg/client/chaosclient" "k8s.io/kubernetes/pkg/client/record" client "k8s.io/kubernetes/pkg/client/unversioned" clientauth "k8s.io/kubernetes/pkg/client/unversioned/auth" "k8s.io/kubernetes/pkg/client/unversioned/clientcmd" clientcmdapi "k8s.io/kubernetes/pkg/client/unversioned/clientcmd/api" "k8s.io/kubernetes/pkg/credentialprovider" "k8s.io/kubernetes/pkg/healthz" "k8s.io/kubernetes/pkg/kubelet" "k8s.io/kubernetes/pkg/kubelet/cadvisor" "k8s.io/kubernetes/pkg/kubelet/cm" "k8s.io/kubernetes/pkg/kubelet/config" kubecontainer "k8s.io/kubernetes/pkg/kubelet/container" "k8s.io/kubernetes/pkg/kubelet/dockertools" "k8s.io/kubernetes/pkg/kubelet/network" "k8s.io/kubernetes/pkg/kubelet/qos" kubetypes "k8s.io/kubernetes/pkg/kubelet/types" "k8s.io/kubernetes/pkg/master/ports" "k8s.io/kubernetes/pkg/util" "k8s.io/kubernetes/pkg/util/chmod" "k8s.io/kubernetes/pkg/util/chown" "k8s.io/kubernetes/pkg/util/io" "k8s.io/kubernetes/pkg/util/mount" nodeutil "k8s.io/kubernetes/pkg/util/node" "k8s.io/kubernetes/pkg/util/oom" "k8s.io/kubernetes/pkg/volume" "github.com/golang/glog" "github.com/spf13/cobra" "github.com/spf13/pflag" "k8s.io/kubernetes/pkg/cloudprovider" ) 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 { Address net.IP AllowPrivileged bool APIServerList []string AuthPath util.StringFlag // Deprecated -- use KubeConfig instead CAdvisorPort uint CertDirectory string CgroupRoot string CloudConfigFile string CloudProvider string ClusterDNS net.IP ClusterDomain string Config string ConfigureCBR0 bool ContainerRuntime string CPUCFSQuota bool DockerDaemonContainer string DockerEndpoint string DockerExecHandlerName string EnableDebuggingHandlers bool EnableServer bool EventBurst int EventRecordQPS float32 FileCheckFrequency time.Duration HealthzBindAddress net.IP HealthzPort int HostnameOverride string HostNetworkSources string HostPIDSources string HostIPCSources string HTTPCheckFrequency time.Duration ImageGCHighThresholdPercent int ImageGCLowThresholdPercent int KubeConfig util.StringFlag LowDiskSpaceThresholdMB int ManifestURL string ManifestURLHeader string MasterServiceNamespace string MaxContainerCount int MaxOpenFiles uint64 MaxPerPodContainerCount int MaxPods int MinimumGCAge time.Duration NetworkPluginDir string NetworkPluginName string NodeStatusUpdateFrequency time.Duration OOMScoreAdj int PodCIDR string PodInfraContainerImage string Port uint ReadOnlyPort uint RegisterNode bool RegisterSchedulable bool RegistryBurst int RegistryPullQPS float64 ResolverConfig string ResourceContainer string RktPath string RktStage1Image string RootDirectory string RunOnce bool StandaloneMode bool StreamingConnectionIdleTimeout time.Duration SyncFrequency time.Duration SystemContainer string TLSCertFile string TLSPrivateKeyFile string ReconcileCIDR bool // Flags intended for testing // Is the kubelet containerized? Containerized bool // Insert a probability of random errors during calls to the master. ChaosChance float64 // Crash immediately, rather than eating panics. ReallyCrashForTesting bool KubeAPIQPS float32 KubeAPIBurst int // Pull images one at a time. SerializeImagePulls bool } // bootstrapping interface for kubelet, targets the initialization protocol type KubeletBootstrap interface { BirthCry() StartGarbageCollection() ListenAndServe(address net.IP, port uint, tlsOptions *kubelet.TLSOptions, auth kubelet.AuthInterface, enableDebuggingHandlers bool) ListenAndServeReadOnly(address net.IP, port uint) Run(<-chan kubetypes.PodUpdate) RunOnce(<-chan kubetypes.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{ Address: net.ParseIP("0.0.0.0"), AuthPath: util.NewStringFlag("/var/lib/kubelet/kubernetes_auth"), // deprecated CAdvisorPort: 4194, CertDirectory: "/var/run/kubernetes", CgroupRoot: "", ConfigureCBR0: false, ContainerRuntime: "docker", CPUCFSQuota: false, DockerDaemonContainer: "/docker-daemon", DockerExecHandlerName: "native", EnableDebuggingHandlers: true, EnableServer: true, FileCheckFrequency: 20 * time.Second, HealthzBindAddress: net.ParseIP("127.0.0.1"), HealthzPort: 10248, HostNetworkSources: kubetypes.AllSource, HostPIDSources: kubetypes.AllSource, HostIPCSources: kubetypes.AllSource, HTTPCheckFrequency: 20 * time.Second, ImageGCHighThresholdPercent: 90, ImageGCLowThresholdPercent: 80, KubeConfig: util.NewStringFlag("/var/lib/kubelet/kubeconfig"), LowDiskSpaceThresholdMB: 256, MasterServiceNamespace: api.NamespaceDefault, MaxContainerCount: 100, MaxPerPodContainerCount: 2, MaxOpenFiles: 1000000, MaxPods: 40, MinimumGCAge: 1 * time.Minute, NetworkPluginDir: "/usr/libexec/kubernetes/kubelet-plugins/net/exec/", NetworkPluginName: "", NodeStatusUpdateFrequency: 10 * time.Second, OOMScoreAdj: qos.KubeletOOMScoreAdj, PodInfraContainerImage: dockertools.PodInfraContainerImage, Port: ports.KubeletPort, ReadOnlyPort: ports.KubeletReadOnlyPort, RegisterNode: true, // will be ignored if no apiserver is configured RegisterSchedulable: true, RegistryBurst: 10, ResourceContainer: "/kubelet", RktPath: "", RktStage1Image: "", RootDirectory: defaultRootDir, SerializeImagePulls: true, StreamingConnectionIdleTimeout: 5 * time.Minute, SyncFrequency: 10 * time.Second, SystemContainer: "", ReconcileCIDR: true, KubeAPIQPS: 5.0, KubeAPIBurst: 10, } } // NewKubeletCommand creates a *cobra.Command object with default parameters func NewKubeletCommand() *cobra.Command { s := NewKubeletServer() s.AddFlags(pflag.CommandLine) cmd := &cobra.Command{ Use: "kubelet", Long: `The kubelet is the primary "node agent" that runs on each node. The kubelet works in terms of a PodSpec. A PodSpec is a YAML or JSON object that describes a pod. The kubelet takes a set of PodSpecs that are provided through various mechanisms (primarily through the apiserver) and ensures that the containers described in those PodSpecs are running and healthy. Other than from an PodSpec from the apiserver, there are three ways that a container manifest can be provided to the Kubelet. File: Path passed as a flag on the command line. This file is rechecked every 20 seconds (configurable with a flag). HTTP endpoint: HTTP endpoint passed as a parameter on the command line. This endpoint is checked every 20 seconds (also configurable with a flag). HTTP server: The kubelet can also listen for HTTP and respond to a simple API (underspec'd currently) to submit a new manifest.`, Run: func(cmd *cobra.Command, args []string) { }, } return cmd } // 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.StringVar(&s.ManifestURLHeader, "manifest-url-header", s.ManifestURLHeader, "HTTP header to use when accessing the manifest URL, with the key separated from the value with a ':', as in 'key:value'") fs.BoolVar(&s.EnableServer, "enable-server", s.EnableServer, "Enable the Kubelet's server") fs.IPVar(&s.Address, "address", s.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 with no authentication/authorization (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. [default=\"*\"]") fs.StringVar(&s.HostPIDSources, "host-pid-sources", s.HostPIDSources, "Comma-separated list of sources from which the Kubelet allows pods to use the host pid namespace. [default=\"*\"]") fs.StringVar(&s.HostIPCSources, "host-ipc-sources", s.HostIPCSources, "Comma-separated list of sources from which the Kubelet allows pods to use the host ipc namespace. [default=\"*\"]") 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.Float32Var(&s.EventRecordQPS, "event-qps", s.EventRecordQPS, "If > 0, limit event creations per second to this value. If 0, unlimited. [default=0.0]") fs.IntVar(&s.EventBurst, "event-burst", s.EventBurst, "Maximum size of a bursty event records, temporarily allows event records to burst to this number, while still not exceeding event-qps. Only used if --event-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 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 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.IPVar(&s.HealthzBindAddress, "healthz-bind-address", s.HealthzBindAddress, "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.StringSliceVar(&s.APIServerList, "api-servers", []string{}, "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-servers 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.IPVar(&s.ClusterDNS, "cluster-dns", s.ClusterDNS, "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", s.StreamingConnectionIdleTimeout, "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.NetworkPluginDir, "network-plugin-dir", s.NetworkPluginDir, " The full path of the directory in which to search for network plugins") 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.RktPath, "rkt-path", s.RktPath, "Path of rkt binary. Leave empty to use the first rkt in $PATH. Only used if --container-runtime='rkt'") fs.StringVar(&s.RktStage1Image, "rkt-stage1-image", s.RktStage1Image, "image to use as stage1. Local paths and http/https URLs are supported. If empty, the 'stage1.aci' in the same directory as '--rkt-path' will be used") 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", s.MaxPods, "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.") fs.StringVar(&s.ResolverConfig, "resolv-conf", kubelet.ResolvConfDefault, "Resolver configuration file used as the basis for the container DNS resolution configuration.") fs.BoolVar(&s.CPUCFSQuota, "cpu-cfs-quota", s.CPUCFSQuota, "Enable CPU CFS quota enforcement for containers that specify CPU limits") // 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]") fs.Uint64Var(&s.MaxOpenFiles, "max-open-files", s.MaxOpenFiles, "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]") fs.Float32Var(&s.KubeAPIQPS, "kube-api-qps", s.KubeAPIQPS, "QPS to use while talking with kubernetes apiserver") fs.IntVar(&s.KubeAPIBurst, "kube-api-burst", s.KubeAPIBurst, "Burst to use while talking with kubernetes apiserver") fs.BoolVar(&s.SerializeImagePulls, "serialize-image-pulls", s.SerializeImagePulls, "Pull images one at a time. We recommend *not* changing the default value on nodes that run docker daemon with version < 1.9 or an Aufs storage backend. Issue #10959 has more details. [default=true]") } // UnsecuredKubeletConfig returns a KubeletConfig suitable for being run, or an error if the server setup // is not valid. It will not start any background processes, and does not include authentication/authorization func (s *KubeletServer) UnsecuredKubeletConfig() (*KubeletConfig, error) { hostNetworkSources, err := kubetypes.GetValidatedSources(strings.Split(s.HostNetworkSources, ",")) if err != nil { return nil, err } hostPIDSources, err := kubetypes.GetValidatedSources(strings.Split(s.HostPIDSources, ",")) if err != nil { return nil, err } hostIPCSources, err := kubetypes.GetValidatedSources(strings.Split(s.HostIPCSources, ",")) if err != nil { return nil, err } mounter := mount.New() var writer io.Writer = &io.StdWriter{} if s.Containerized { glog.V(2).Info("Running kubelet in containerized mode (experimental)") mounter = mount.NewNsenterMounter() writer = &io.NsenterWriter{} } chmodRunner := chmod.New() chownRunner := chown.New() tlsOptions, err := s.InitializeTLS() if err != nil { return nil, err } 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{} } imageGCPolicy := kubelet.ImageGCPolicy{ HighThresholdPercent: s.ImageGCHighThresholdPercent, LowThresholdPercent: s.ImageGCLowThresholdPercent, } diskSpacePolicy := kubelet.DiskSpacePolicy{ DockerFreeDiskMB: s.LowDiskSpaceThresholdMB, RootFreeDiskMB: s.LowDiskSpaceThresholdMB, } manifestURLHeader := make(http.Header) if s.ManifestURLHeader != "" { pieces := strings.Split(s.ManifestURLHeader, ":") if len(pieces) != 2 { return nil, fmt.Errorf("manifest-url-header must have a single ':' key-value separator, got %q", s.ManifestURLHeader) } manifestURLHeader.Set(pieces[0], pieces[1]) } return &KubeletConfig{ Address: s.Address, AllowPrivileged: s.AllowPrivileged, Auth: nil, // default does not enforce auth[nz] CAdvisorInterface: nil, // launches background processes, not set here CgroupRoot: s.CgroupRoot, Cloud: nil, // cloud provider might start background processes ClusterDNS: s.ClusterDNS, ClusterDomain: s.ClusterDomain, ConfigFile: s.Config, ConfigureCBR0: s.ConfigureCBR0, ContainerManager: nil, ContainerRuntime: s.ContainerRuntime, CPUCFSQuota: s.CPUCFSQuota, DiskSpacePolicy: diskSpacePolicy, DockerClient: dockertools.ConnectToDockerOrDie(s.DockerEndpoint), DockerDaemonContainer: s.DockerDaemonContainer, DockerExecHandler: dockerExecHandler, EnableDebuggingHandlers: s.EnableDebuggingHandlers, EnableServer: s.EnableServer, EventBurst: s.EventBurst, EventRecordQPS: s.EventRecordQPS, FileCheckFrequency: s.FileCheckFrequency, HostnameOverride: s.HostnameOverride, HostNetworkSources: hostNetworkSources, HostPIDSources: hostPIDSources, HostIPCSources: hostIPCSources, HTTPCheckFrequency: s.HTTPCheckFrequency, ImageGCPolicy: imageGCPolicy, KubeClient: nil, ManifestURL: s.ManifestURL, ManifestURLHeader: manifestURLHeader, MasterServiceNamespace: s.MasterServiceNamespace, MaxContainerCount: s.MaxContainerCount, MaxOpenFiles: s.MaxOpenFiles, MaxPerPodContainerCount: s.MaxPerPodContainerCount, MaxPods: s.MaxPods, MinimumGCAge: s.MinimumGCAge, Mounter: mounter, ChownRunner: chownRunner, ChmodRunner: chmodRunner, NetworkPluginName: s.NetworkPluginName, NetworkPlugins: ProbeNetworkPlugins(s.NetworkPluginDir), NodeStatusUpdateFrequency: s.NodeStatusUpdateFrequency, 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, ResourceContainer: s.ResourceContainer, RktPath: s.RktPath, RktStage1Image: s.RktStage1Image, RootDirectory: s.RootDirectory, Runonce: s.RunOnce, SerializeImagePulls: s.SerializeImagePulls, StandaloneMode: (len(s.APIServerList) == 0), StreamingConnectionIdleTimeout: s.StreamingConnectionIdleTimeout, SyncFrequency: s.SyncFrequency, SystemContainer: s.SystemContainer, TLSOptions: tlsOptions, Writer: writer, VolumePlugins: ProbeVolumePlugins(), }, nil } // Run runs the specified KubeletServer for the given KubeletConfig. This should never exit. // The kcfg argument may be nil - if so, it is initialized from the settings on KubeletServer. // Otherwise, the caller is assumed to have set up the KubeletConfig object and all defaults // will be ignored. func (s *KubeletServer) Run(kcfg *KubeletConfig) error { var err error if kcfg == nil { cfg, err := s.UnsecuredKubeletConfig() if err != nil { return err } kcfg = cfg clientConfig, err := s.CreateAPIServerClientConfig() if err == nil { kcfg.KubeClient, err = client.New(clientConfig) } if err != nil && len(s.APIServerList) > 0 { glog.Warningf("No API client: %v", err) } cloud, err := cloudprovider.InitCloudProvider(s.CloudProvider, s.CloudConfigFile) if err != nil { return err } glog.V(2).Infof("Successfully initialized cloud provider: %q from the config file: %q\n", s.CloudProvider, s.CloudConfigFile) kcfg.Cloud = cloud } if kcfg.CAdvisorInterface == nil { kcfg.CAdvisorInterface, err = cadvisor.New(s.CAdvisorPort) if err != nil { return err } } if kcfg.ContainerManager == nil { kcfg.ContainerManager, err = cm.NewContainerManager(kcfg.Mounter, kcfg.CAdvisorInterface) if err != nil { return err } } util.ReallyCrash = s.ReallyCrashForTesting rand.Seed(time.Now().UTC().UnixNano()) credentialprovider.SetPreferredDockercfgPath(s.RootDirectory) glog.V(2).Infof("Using root directory: %v", s.RootDirectory) // TODO(vmarmol): Do this through container config. oomAdjuster := kcfg.OOMAdjuster if err := oomAdjuster.ApplyOOMScoreAdj(0, s.OOMScoreAdj); err != nil { glog.Warning(err) } if err := RunKubelet(kcfg); err != nil { return err } if s.HealthzPort > 0 { healthz.DefaultHealthz() go util.Until(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, util.NeverStop) } 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, nil, nil); 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 } // Override kubeconfig qps/burst settings from flags clientConfig.QPS = s.KubeAPIQPS clientConfig.Burst = s.KubeAPIBurst 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, readOnlyPort uint, masterServiceNamespace string, volumePlugins []volume.VolumePlugin, tlsOptions *kubelet.TLSOptions, cadvisorInterface cadvisor.Interface, configFilePath string, cloud cloudprovider.Interface, osInterface kubecontainer.OSInterface, fileCheckFrequency, httpCheckFrequency, minimumGCAge, nodeStatusUpdateFrequency, syncFrequency time.Duration, maxPods int, containerManager cm.ContainerManager) *KubeletConfig { imageGCPolicy := kubelet.ImageGCPolicy{ HighThresholdPercent: 90, LowThresholdPercent: 80, } diskSpacePolicy := kubelet.DiskSpacePolicy{ DockerFreeDiskMB: 256, RootFreeDiskMB: 256, } kcfg := KubeletConfig{ Address: net.ParseIP(address), CAdvisorInterface: cadvisorInterface, CgroupRoot: "", Cloud: cloud, ConfigFile: configFilePath, ContainerManager: containerManager, ContainerRuntime: "docker", CPUCFSQuota: false, DiskSpacePolicy: diskSpacePolicy, DockerClient: dockerClient, DockerDaemonContainer: "/docker-daemon", DockerExecHandler: &dockertools.NativeExecHandler{}, EnableDebuggingHandlers: true, EnableServer: true, FileCheckFrequency: fileCheckFrequency, HostnameOverride: hostname, HTTPCheckFrequency: httpCheckFrequency, ImageGCPolicy: imageGCPolicy, KubeClient: client, ManifestURL: manifestURL, MasterServiceNamespace: masterServiceNamespace, MaxContainerCount: 100, MaxOpenFiles: 1024, MaxPerPodContainerCount: 2, MaxPods: maxPods, MinimumGCAge: minimumGCAge, Mounter: mount.New(), ChownRunner: chown.New(), ChmodRunner: chmod.New(), NodeStatusUpdateFrequency: nodeStatusUpdateFrequency, OOMAdjuster: oom.NewFakeOOMAdjuster(), OSInterface: osInterface, PodInfraContainerImage: dockertools.PodInfraContainerImage, Port: port, ReadOnlyPort: readOnlyPort, RegisterNode: true, RegisterSchedulable: true, ResolverConfig: kubelet.ResolvConfDefault, ResourceContainer: "/kubelet", RootDirectory: rootDir, SerializeImagePulls: true, SyncFrequency: syncFrequency, SystemContainer: "", TLSOptions: tlsOptions, VolumePlugins: volumePlugins, Writer: &io.StdWriter{}, } 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) error { kcfg.Hostname = nodeutil.GetHostname(kcfg.HostnameOverride) if len(kcfg.NodeName) == 0 { // 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.V(3).Infof) if kcfg.KubeClient != nil { glog.V(4).Infof("Sending events to api server.") if kcfg.EventRecordQPS == 0.0 { eventBroadcaster.StartRecordingToSink(kcfg.KubeClient.Events("")) } else { eventClient := *kcfg.KubeClient eventClient.Throttle = util.NewTokenBucketRateLimiter(kcfg.EventRecordQPS, kcfg.EventBurst) eventBroadcaster.StartRecordingToSink(eventClient.Events("")) } } else { glog.Warning("No api server defined - no events will be sent to API server.") } privilegedSources := capabilities.PrivilegedSources{ HostNetworkSources: kcfg.HostNetworkSources, HostPIDSources: kcfg.HostPIDSources, HostIPCSources: kcfg.HostIPCSources, } capabilities.Setup(kcfg.AllowPrivileged, privilegedSources, 0) credentialprovider.SetPreferredDockercfgPath(kcfg.RootDirectory) builder := kcfg.Builder 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) } util.ApplyRLimitForSelf(kcfg.MaxOpenFiles) // 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.Until(func() { k.Run(podCfg.Updates()) }, 0, util.NeverStop) // start the kubelet server if kc.EnableServer { go util.Until(func() { k.ListenAndServe(kc.Address, kc.Port, kc.TLSOptions, kc.Auth, kc.EnableDebuggingHandlers) }, 0, util.NeverStop) } if kc.ReadOnlyPort > 0 { go util.Until(func() { k.ListenAndServeReadOnly(kc.Address, kc.ReadOnlyPort) }, 0, util.NeverStop) } } func makePodSourceConfig(kc *KubeletConfig) *config.PodConfig { // source of all configuration cfg := config.NewPodConfig(config.PodConfigNotificationIncremental, 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(kubetypes.FileSource)) } // define url config source if kc.ManifestURL != "" { glog.Infof("Adding manifest url %q with HTTP header %v", kc.ManifestURL, kc.ManifestURLHeader) config.NewSourceURL(kc.ManifestURL, kc.ManifestURLHeader, kc.NodeName, kc.HTTPCheckFrequency, cfg.Channel(kubetypes.HTTPSource)) } if kc.KubeClient != nil { glog.Infof("Watching apiserver") config.NewSourceApiserver(kc.KubeClient, kc.NodeName, cfg.Channel(kubetypes.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 { Address net.IP AllowPrivileged bool Auth kubelet.AuthInterface Builder KubeletBuilder CAdvisorInterface cadvisor.Interface CgroupRoot string Cloud cloudprovider.Interface ClusterDNS net.IP ClusterDomain string ConfigFile string ConfigureCBR0 bool ContainerManager cm.ContainerManager ContainerRuntime string CPUCFSQuota bool DiskSpacePolicy kubelet.DiskSpacePolicy DockerClient dockertools.DockerInterface DockerDaemonContainer string DockerExecHandler dockertools.ExecHandler EnableDebuggingHandlers bool EnableServer bool EventBurst int EventRecordQPS float32 FileCheckFrequency time.Duration Hostname string HostnameOverride string HostNetworkSources []string HostPIDSources []string HostIPCSources []string HTTPCheckFrequency time.Duration ImageGCPolicy kubelet.ImageGCPolicy KubeClient *client.Client ManifestURL string ManifestURLHeader http.Header MasterServiceNamespace string MaxContainerCount int MaxOpenFiles uint64 MaxPerPodContainerCount int MaxPods int MinimumGCAge time.Duration Mounter mount.Interface ChownRunner chown.Interface ChmodRunner chmod.Interface NetworkPluginName string NetworkPlugins []network.NetworkPlugin NodeName string NodeStatusUpdateFrequency time.Duration 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 ResourceContainer string RktPath string RktStage1Image string RootDirectory string Runonce bool SerializeImagePulls bool StandaloneMode bool StreamingConnectionIdleTimeout time.Duration SyncFrequency time.Duration SystemContainer string TLSOptions *kubelet.TLSOptions Writer io.Writer VolumePlugins []volume.VolumePlugin } 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 := kubecontainer.ContainerGCPolicy{ MinAge: kc.MinimumGCAge, MaxPerPodContainer: kc.MaxPerPodContainerCount, MaxContainers: kc.MaxContainerCount, } daemonEndpoints := &api.NodeDaemonEndpoints{ KubeletEndpoint: api.DaemonEndpoint{Port: int(kc.Port)}, } pc = kc.PodConfig if pc == nil { 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, kc.EventRecordQPS, kc.EventBurst, gcPolicy, pc.SeenAllSources, kc.RegisterNode, kc.RegisterSchedulable, kc.StandaloneMode, kc.ClusterDomain, 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.RktPath, kc.RktStage1Image, kc.Mounter, kc.Writer, kc.ChownRunner, kc.ChmodRunner, kc.DockerDaemonContainer, kc.SystemContainer, kc.ConfigureCBR0, kc.PodCIDR, kc.ReconcileCIDR, kc.MaxPods, kc.DockerExecHandler, kc.ResolverConfig, kc.CPUCFSQuota, daemonEndpoints, kc.OOMAdjuster, kc.SerializeImagePulls, kc.ContainerManager, ) if err != nil { return nil, nil, err } k.BirthCry() k.StartGarbageCollection() return k, pc, nil }