feat: Make Kube API QPS/burst and backend poll rate/burst configurable (#236)

Author: ifutivic

cmd/server.go

@@ -65,6 +65,10 @@ func init() {
 	serverCmd.PersistentFlags().Bool("pre-archive", false, "Enable support for copying single files to containers without starting them")
 	serverCmd.PersistentFlags().Bool("disable-services", false, "Disable service creation (requires a network solution such as kubedock-dns)")
 	serverCmd.PersistentFlags().Bool("ignore-container-memory", false, "Ignore container memory setting and use requests/limits from gobal settings or container labels")
+	serverCmd.PersistentFlags().Float32("kube-api-qps", 0, "Maximum QPS for requests to the Kubernetes API (0 uses client default)")
+	serverCmd.PersistentFlags().Int("kube-api-burst", 0, "Maximum burst for requests to the Kubernetes API (0 uses client default)")
+	serverCmd.PersistentFlags().Float64("poll-rate", 0, "Maximum polling requests per second towards the backend (0 uses default of 1)")
+	serverCmd.PersistentFlags().Int("poll-burst", 0, "Maximum burst of poll requests towards the backend (0 uses default of 3)")
 
 	viper.BindPFlag("server.listen-addr", serverCmd.PersistentFlags().Lookup("listen-addr"))
 	viper.BindPFlag("server.socket", serverCmd.PersistentFlags().Lookup("unix-socket"))
@@ -97,6 +101,10 @@ func init() {
 	viper.BindPFlag("pre-archive", serverCmd.PersistentFlags().Lookup("pre-archive"))
 	viper.BindPFlag("disable-services", serverCmd.PersistentFlags().Lookup("disable-services"))
 	viper.BindPFlag("ignore-container-memory", serverCmd.PersistentFlags().Lookup("ignore-container-memory"))
+	viper.BindPFlag("kubernetes.qps", serverCmd.PersistentFlags().Lookup("kube-api-qps"))
+	viper.BindPFlag("kubernetes.burst", serverCmd.PersistentFlags().Lookup("kube-api-burst"))
+	viper.BindPFlag("server.poll-rate", serverCmd.PersistentFlags().Lookup("poll-rate"))
+	viper.BindPFlag("server.poll-burst", serverCmd.PersistentFlags().Lookup("poll-burst"))
 
 	viper.BindEnv("server.listen-addr", "SERVER_LISTEN_ADDR")
 	viper.BindEnv("server.tls-enable", "SERVER_TLS_ENABLE")
@@ -120,6 +128,10 @@ func init() {
 	viper.BindEnv("kubernetes.timeout", "TIME_OUT")
 	viper.BindEnv("reaper.reapmax", "REAPER_REAPMAX")
 	viper.BindEnv("verbosity", "VERBOSITY")
+	viper.BindEnv("kubernetes.qps", "K8S_QPS")
+	viper.BindEnv("kubernetes.burst", "K8S_BURST")
+	viper.BindEnv("server.poll-rate", "POLL_RATE")
+	viper.BindEnv("server.poll-burst", "POLL_BURST")
 
 	serverCmd.PersistentFlags().Lookup("tls-enable").Hidden = true
 	serverCmd.PersistentFlags().Lookup("tls-key-file").Hidden = true

config.md

@@ -42,6 +42,10 @@ The `server` command is the actual kubedock server, and is the command to start
 |server|--label||K8S_LABEL_label|label that need to be added to every k8s resource (key=value)|
 |server|--active-deadline-seconds|-1|K8S_ACTIVE_DEADLINE_SECONDS|Default value for pod deadline, in seconds (a negative value means no deadline)|
 |server|--ignore-container-memory|false||Ignore container memory setting and use requests/limits from gobal settings or container labels|
+|server|--kube-api-qps|0|K8S_QPS|Maximum QPS for requests to the Kubernetes API (0 uses client default)|
+|server|--kube-api-burst|0|K8S_BURST|Maximum burst for requests to the Kubernetes API (0 uses client default)|
+|server|--poll-rate|0|POLL_RATE|Maximum polling requests per second towards the backend (0 uses default of 1)|
+|server|--poll-burst|0|POLL_BURST|Maximum burst of poll requests towards the backend (0 uses default of 3)|
 |dind|--unix-socket|/var/run/docker.sock||Unix socket to listen to|
 |dind|--kubedock-url|||Kubedock url to proxy requests to|
 |dind|--verbosity / -v|1|VERBOSITY|Log verbosity level|

internal/config/kubernetes.go

@@ -62,5 +62,11 @@ func GetKubernetes() (*rest.Config, error) {
 			return nil, err
 		}
 	}
+	if qps := float32(viper.GetFloat64("kubernetes.qps")); qps > 0 {
+		config.QPS = qps
+	}
+	if burst := viper.GetInt("kubernetes.burst"); burst > 0 {
+		config.Burst = burst
+	}
 	return config, nil
 }

internal/server/main.go

@@ -142,6 +142,9 @@ func (s *Server) getGinEngine() *gin.Engine {
 
 	icm := viper.GetBool("ignore-container-memory")
 
+	pollRate := viper.GetFloat64("server.poll-rate")
+	pollBurst := viper.GetInt("server.poll-burst")
+
 	klog.Infof("using namespace: %s", viper.GetString("kubernetes.namespace"))
 
 	cr, err := common.NewContextRouter(s.kub, common.Config{
@@ -158,6 +161,8 @@ func (s *Server) getGinEngine() *gin.Engine {
 		NamePrefix:            podprfx,
 		ActiveDeadlineSeconds: ads,
 		IgnoreContainerMemory: icm,
+		PollRate:              pollRate,
+		PollBurst:             pollBurst,
 	})
 	if err != nil {
 		klog.Errorf("error setting up context: %s", err)

internal/server/routes/common/context.go

@@ -9,10 +9,10 @@ import (
 )
 
 const (
-	// PollRate defines maximum polling request per second towards the backend
-	PollRate = 1
-	// PollBurst defines maximum burst poll requests towards the backend
-	PollBurst = 3
+	// DefaultPollRate defines maximum polling request per second towards the backend
+	DefaultPollRate = 1
+	// DefaultPollBurst defines maximum burst poll requests towards the backend
+	DefaultPollBurst = 3
 )
 
 // Config is the structure to instantiate a Router object
@@ -43,6 +43,12 @@ type Config struct {
 	NodeSelector string
 	// IgnoreContainerMemory is used to ignore Docker memory settings and use requests/limits from Kubedock config
 	IgnoreContainerMemory bool
+	// PollRate defines maximum polling requests per second towards the backend.
+	// Defaults to DefaultPollRate if zero.
+	PollRate float64
+	// PollBurst defines the maximum burst of poll requests towards the backend.
+	// Defaults to DefaultPollBurst if zero.
+	PollBurst int
 }
 
 // ContextRouter is the object that contains shared context for the kubedock API endpoints.
@@ -60,12 +66,20 @@ func NewContextRouter(kub backend.Backend, cfg Config) (*ContextRouter, error) {
 	if err != nil {
 		return nil, err
 	}
+	pollRate := cfg.PollRate
+	if pollRate <= 0 {
+		pollRate = DefaultPollRate
+	}
+	pollBurst := cfg.PollBurst
+	if pollBurst <= 0 {
+		pollBurst = DefaultPollBurst
+	}
 	cr := &ContextRouter{
 		Config:  cfg,
 		DB:      db,
 		Backend: kub,
 		Events:  events.New(),
-		Limiter: rate.NewLimiter(PollRate, PollBurst),
+		Limiter: rate.NewLimiter(rate.Limit(pollRate), pollBurst),
 	}
 	return cr, nil
 }