flag controlled RLIMIT_NOFILE for kubelet.

cmd/kubelet/app/server.go

@@ -105,6 +105,7 @@ type KubeletServer struct {
 	ManifestURLHeader              string
 	MasterServiceNamespace         string
 	MaxContainerCount              int
+	MaxOpenFiles                   uint64
 	MaxPerPodContainerCount        int
 	MaxPods                        int
 	MinimumGCAge                   time.Duration
@@ -183,6 +184,7 @@ func NewKubeletServer() *KubeletServer {
 		MasterServiceNamespace:      api.NamespaceDefault,
 		MaxContainerCount:           100,
 		MaxPerPodContainerCount:     2,
+		MaxOpenFiles:                1000000,
 		MinimumGCAge:                1 * time.Minute,
 		NetworkPluginDir:            "/usr/libexec/kubernetes/kubelet-plugins/net/exec/",
 		NetworkPluginName:           "",
@@ -275,6 +277,7 @@ func (s *KubeletServer) AddFlags(fs *pflag.FlagSet) {
 	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", 1000000, "Number of files that can be opened by Kubelet process. [default=1000000]")
 }
 
 // KubeletConfig returns a KubeletConfig suitable for being run, or an error if the server setup
@@ -370,6 +373,7 @@ func (s *KubeletServer) KubeletConfig() (*KubeletConfig, error) {
 		ManifestURLHeader:         manifestURLHeader,
 		MasterServiceNamespace:    s.MasterServiceNamespace,
 		MaxContainerCount:         s.MaxContainerCount,
+		MaxOpenFiles:              s.MaxOpenFiles,
 		MaxPerPodContainerCount:   s.MaxPerPodContainerCount,
 		MaxPods:                   s.MaxPods,
 		MinimumGCAge:              s.MinimumGCAge,
@@ -628,6 +632,7 @@ func SimpleKubelet(client *client.Client,
 		ManifestURL:               manifestURL,
 		MasterServiceNamespace:    masterServiceNamespace,
 		MaxContainerCount:         100,
+		MaxOpenFiles:              1024,
 		MaxPerPodContainerCount:   2,
 		MaxPods:                   32,
 		MinimumGCAge:              minimumGCAge,
@@ -714,6 +719,9 @@ func RunKubelet(kcfg *KubeletConfig, builder KubeletBuilder) error {
 	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 {
@@ -801,6 +809,7 @@ type KubeletConfig struct {
 	ManifestURLHeader              http.Header
 	MasterServiceNamespace         string
 	MaxContainerCount              int
+	MaxOpenFiles                   uint64
 	MaxPerPodContainerCount        int
 	MaxPods                        int
 	MinimumGCAge                   time.Duration

pkg/util/resource_container_linux.go

@@ -20,6 +20,7 @@ package util
 
 import (
 	"os"
+	"syscall"
 
 	"github.com/docker/libcontainer/cgroups/fs"
 	"github.com/docker/libcontainer/configs"
@@ -39,3 +40,7 @@ func RunInResourceContainer(containerName string) error {
 
 	return manager.Apply(os.Getpid())
 }
+
+func ApplyRLimitForSelf(maxOpenFiles uint64) {
+	syscall.Setrlimit(syscall.RLIMIT_NOFILE, &syscall.Rlimit{Max: maxOpenFiles, Cur: maxOpenFiles})
+}

pkg/util/resource_container_unsupported.go

@@ -25,3 +25,7 @@ import (
 func RunInResourceContainer(containerName string) error {
 	return errors.New("resource-only containers unsupported in this platform")
 }
+
+func ApplyRLimitForSelf(maxOpenFiles uint64) error {
+	return errors.New("SetRLimit unsupported in this platform")
+}