Cooldown period

api/handle.go

@@ -19,7 +19,7 @@ type scaleRequest struct {
 	Direction bool   `json:"direction"`
 }
 
-func Handle(scalers autoscaler.Autoscalers) func(w http.ResponseWriter, r *http.Request) {
+func Handle(scalers *autoscaler.Autoscalers) func(w http.ResponseWriter, r *http.Request) {
 	return func(w http.ResponseWriter, r *http.Request) {
 		var err error
 		requestDump, err := httputil.DumpRequest(r, true)
@@ -61,7 +61,7 @@ func Handle(scalers autoscaler.Autoscalers) func(w http.ResponseWriter, r *http.
 			return
 		}
 
-		s, ok := scalers[fmt.Sprintf("%s/%s", autoscalerName, serviceName)]
+		s, ok := (*scalers)[fmt.Sprintf("%s/%s", autoscalerName, serviceName)]
 		if !ok {
 			logrus.WithFields(logrus.Fields{
 				"path": r.URL.RawPath,

api/router.go

@@ -6,10 +6,10 @@ import (
 	"github.com/gorilla/mux"
 )
 
-func GetRouter(core core.Core, eventChannel chan *logrus.Entry) *mux.Router {
+func GetRouter(core *core.Core, eventChannel chan *logrus.Entry) *mux.Router {
 	r := mux.NewRouter()
-	r.HandleFunc("/handle/{autoscaler_name}/{service_name}", Handle(core.Autoscalers)).Methods("POST")
-	r.HandleFunc("/handle/{autoscaler_name}/{service_name}/{direction}", Handle(core.Autoscalers)).Methods("POST")
+	r.HandleFunc("/handle/{autoscaler_name}/{service_name}", Handle(&core.Autoscalers)).Methods("POST")
+	r.HandleFunc("/handle/{autoscaler_name}/{service_name}/{direction}", Handle(&core.Autoscalers)).Methods("POST")
 	r.HandleFunc("/autoscaler", AutoscalerList(core.Autoscalers)).Methods("GET")
 	r.HandleFunc("/health", Health()).Methods("GET")
 	r.HandleFunc("/events", Events(eventChannel)).Methods("GET")

autoscaler/autoscaler.go

@@ -1,6 +1,15 @@
 package autoscaler
 
-import "github.com/Sirupsen/logrus"
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"github.com/Sirupsen/logrus"
+	"github.com/docker/docker/api/types"
+	"github.com/docker/docker/client"
+	"github.com/pkg/errors"
+)
 
 type Provider interface {
 	Scale(string, int, bool) error
@@ -14,26 +23,64 @@ type Autoscaler struct {
 	serviceId  string
 	targetUp   int
 	targetDown int
+	CoolDown   int
 }
 
-func NewAutoscaler(p Provider, serviceId string, targetUp int, targetDown int) Autoscaler {
+func NewAutoscaler(p Provider, serviceId string, targetUp int, targetDown int, coolDown int) Autoscaler {
 	a := Autoscaler{
 		provider:   p,
 		serviceId:  serviceId,
 		targetUp:   targetUp,
 		targetDown: targetDown,
+		CoolDown:   coolDown,
 	}
 	return a
 }
 
+func canScale(serviceId string, coolDown time.Duration) (retval bool, err error) {
+	retval = false
+	err = nil
+	ctx := context.Background()
+	dockerClient, err := client.NewEnvClient()
+	if err != nil {
+		logrus.WithField("error", err).Debug("Problem communication with Docker")
+		return
+	}
+
+	services, err := dockerClient.ServiceList(ctx, types.ServiceListOptions{})
+	if err != nil {
+		logrus.WithField("error", err).Debug("Bad comunication with Docker.")
+		return
+	}
+
+	for _, service := range services {
+		if service.Spec.Name != serviceId {
+			continue
+		}
+		// now < updatedAt + coolDown ??
+		if time.Now().Before(service.Meta.UpdatedAt.Add(coolDown)) {
+			err = errors.New(fmt.Sprintf("Cooldown period for %f seconds", service.Meta.UpdatedAt.Add(coolDown).Sub(time.Now()).Seconds()))
+			break
+		} else {
+			retval = true
+			break
+		}
+	}
+	return
+}
+
 func (a *Autoscaler) ScaleUp() error {
 	logrus.WithFields(logrus.Fields{
 		"service":   a.serviceId,
 		"direction": true,
 	}).Infof("Received a new request to scale up %s with %d task.", a.serviceId, a.targetUp)
 
-	err := a.provider.Scale(a.serviceId, a.targetUp, true)
+	if ok, err := canScale(a.serviceId, time.Duration(a.CoolDown)*time.Second); ok == false {
+		logrus.Warn("Cannot scale up during coolDown period!")
+		return err
+	}
 
+	err := a.provider.Scale(a.serviceId, a.targetUp, true)
 	if err != nil {
 		logrus.WithFields(logrus.Fields{
 			"service":   a.serviceId,
@@ -56,6 +103,10 @@ func (a *Autoscaler) ScaleDown() error {
 		"direction": false,
 	}).Infof("Received a new request to scale down %s with %d task.", a.serviceId, a.targetDown)
 
+	if ok, err := canScale(a.serviceId, time.Duration(a.CoolDown)*time.Second); ok == false {
+		logrus.Warn("Cannot scale down during coolDown period!")
+		return err
+	}
 	err := a.provider.Scale(a.serviceId, a.targetDown, false)
 
 	if err != nil {

cmd/daemon.go

@@ -99,7 +99,7 @@ func (c *DaemonCmd) Run(args []string) int {
 	}()
 
 	// Add routing
-	router := api.GetRouter(coreEngine, c.EventChannel)
+	router := api.GetRouter(&coreEngine, c.EventChannel)
 	logrus.Infof("API Server run on port %s", port)
 	http.ListenAndServe(port, router)
 	return 0

core/autodetect.go

@@ -64,8 +64,9 @@ func getAutoscalerByService(p autoscaler.Provider, an swarm.Annotations) (autosc
 	}
 	up := convertStringLabelToInt("orbiter.up", an.Labels)
 	down := convertStringLabelToInt("orbiter.down", an.Labels)
-	as := autoscaler.NewAutoscaler(p, an.Name, up, down)
-	logrus.Debugf("Registering  /handle/autoswarm/%s  to orbiter. (UP %d, DOWN %d)", an.Name, up, down)
+	cool := convertStringLabelToInt("orbiter.cooldown", an.Labels)
+	as := autoscaler.NewAutoscaler(p, an.Name, up, down, cool)
+	logrus.Infof("Registering  /handle/autoswarm/%s  to orbiter. (UP %d, DOWN %d, COOL %d)", an.Name, up, down, cool)
 	return as, nil
 }
 

core/conf.go

@@ -5,10 +5,9 @@ import (
 )
 
 type PolicyConf struct {
-	// Number of tasks to start during a scale up
-	Up int `yaml:"up"`
-	// Number of tasks to start during a scale down
-	Down int `yaml:"down"`
+	Up       int `yaml:"up"`       // Number of tasks to start during a scale up
+	Down     int `yaml:"down"`     // Number of tasks to start during a scale down
+	CoolDown int `yaml:"cooldown"` // Number of milliseconds to sleep avoidin too quick scale
 }
 
 type AutoscalerConf struct {

core/daemon.go

@@ -19,7 +19,7 @@ func NewCoreByConfig(c map[string]AutoscalerConf, core *Core) error {
 			return err
 		}
 		for serviceName, policy := range scaler.Policies {
-			scalers[fmt.Sprintf("%s/%s", scalerName, serviceName)] = autoscaler.NewAutoscaler(p, serviceName, policy.Up, policy.Down)
+			scalers[fmt.Sprintf("%s/%s", scalerName, serviceName)] = autoscaler.NewAutoscaler(p, serviceName, policy.Up, policy.Down, policy.CoolDown)
 		}
 	}
 	core.Autoscalers = scalers