Fixes prometheus gauges

Fix session close. Now PWD gets disconnected from network before
deleting it.

services/client.go

@@ -4,20 +4,8 @@ import (
 	"log"
 
 	"github.com/googollee/go-socket.io"
-	"github.com/prometheus/client_golang/prometheus"
 )
 
-var (
-	clientsGauge = prometheus.NewGauge(prometheus.GaugeOpts{
-		Name: "clients",
-		Help: "Clients",
-	})
-)
-
-func init() {
-	prometheus.MustRegister(clientsGauge)
-}
-
 type ViewPort struct {
 	Rows uint
 	Cols uint
@@ -35,7 +23,6 @@ func (c *Client) ResizeViewPort(cols, rows uint) {
 }
 
 func NewClient(so socketio.Socket, session *Session) *Client {
-	clientsGauge.Inc()
 	so.Join(session.Id)
 
 	c := &Client{so: so, Id: so.Id()}
@@ -67,7 +54,6 @@ func NewClient(so socketio.Socket, session *Session) *Client {
 	})
 
 	so.On("disconnection", func() {
-		clientsGauge.Dec()
 		// Client has disconnected. Remove from session and recheck terminal sizes.
 		for i, cl := range session.clients {
 			if cl.Id == c.Id {
@@ -83,6 +69,7 @@ func NewClient(so socketio.Socket, session *Session) *Client {
 				instance.ResizeTerminal(vp.Cols, vp.Rows)
 			}
 		}
+		setGauges()
 	})
 	return c
 }

services/docker.go

@@ -142,6 +142,17 @@ func ConnectNetwork(containerId, networkId string) error {
 
 	return nil
 }
+func DisconnectNetwork(containerId, networkId string) error {
+	err := c.NetworkDisconnect(context.Background(), networkId, containerId, true)
+
+	if err != nil {
+		log.Printf("Disconnection of container from network err [%s]\n", err)
+
+		return err
+	}
+
+	return nil
+}
 
 func DeleteNetwork(id string) error {
 	err := c.NetworkRemove(context.Background(), id)

services/instance.go

@@ -11,22 +11,10 @@ import (
 
 	"github.com/docker/docker/api/types"
 	"github.com/docker/docker/client"
-	"github.com/prometheus/client_golang/prometheus"
 )
 
 var rw sync.Mutex
 
-var (
-	instancesGauge = prometheus.NewGauge(prometheus.GaugeOpts{
-		Name: "instances",
-		Help: "Instances",
-	})
-)
-
-func init() {
-	prometheus.MustRegister(instancesGauge)
-}
-
 type Instance struct {
 	session      *Session                `json:"-"`
 	Name         string                  `json:"name"`
@@ -102,7 +90,7 @@ func NewInstance(session *Session) (*Instance, error) {
 
 	wsServer.BroadcastTo(session.Id, "new instance", instance.Name, instance.IP, instance.Hostname)
 
-	instancesGauge.Inc()
+	setGauges()
 
 	return instance, nil
 }
@@ -156,7 +144,7 @@ func DeleteInstance(session *Session, instance *Instance) error {
 
 	wsServer.BroadcastTo(session.Id, "delete instance", instance.Name)
 
-	instancesGauge.Dec()
+	setGauges()
 
 	return err
 }

services/session.go

@@ -23,10 +23,20 @@ var (
 		Name: "sessions",
 		Help: "Sessions",
 	})
+	clientsGauge = prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "clients",
+		Help: "Clients",
+	})
+	instancesGauge = prometheus.NewGauge(prometheus.GaugeOpts{
+		Name: "instances",
+		Help: "Instances",
+	})
 )
 
 func init() {
 	prometheus.MustRegister(sessionsGauge)
+	prometheus.MustRegister(clientsGauge)
+	prometheus.MustRegister(instancesGauge)
 }
 
 var wsServer *socketio.Server
@@ -64,6 +74,7 @@ func (s *Session) GetSmallestViewPort() ViewPort {
 
 func (s *Session) AddNewClient(c *Client) {
 	s.clients = append(s.clients, c)
+	setGauges()
 }
 
 func (s *Session) SchedulePeriodicTasks() {
@@ -141,14 +152,12 @@ func CloseSession(s *Session) error {
 	s.rw.Lock()
 	defer s.rw.Unlock()
 
-	sessionsGauge.Dec()
 	if s.ticker != nil {
 		s.ticker.Stop()
 	}
 	wsServer.BroadcastTo(s.Id, "session end")
 	for _, c := range s.clients {
 		c.so.Emit("disconnect")
-		clientsGauge.Dec()
 	}
 	log.Printf("Starting clean up of session [%s]\n", s.Id)
 	for _, i := range s.Instances {
@@ -160,6 +169,12 @@ func CloseSession(s *Session) error {
 			return err
 		}
 	}
+	// Disconnect PWD daemon from the network
+	if err := DisconnectNetwork("pwd", s.Id); err != nil {
+		log.Println("ERROR NETWORKING")
+		return err
+	}
+	log.Printf("Connected pwd to network [%s]\n", s.Id)
 	if err := DeleteNetwork(s.Id); err != nil {
 		log.Println(err)
 		return err
@@ -170,6 +185,7 @@ func CloseSession(s *Session) error {
 	if err := saveSessionsToDisk(); err != nil {
 		return err
 	}
+	setGauges()
 	log.Printf("Cleaned up session [%s]\n", s.Id)
 	return nil
 }
@@ -225,7 +241,7 @@ func NewSession() (*Session, error) {
 		return nil, err
 	}
 
-	sessionsGauge.Inc()
+	setGauges()
 	return s, nil
 }
 
@@ -243,6 +259,20 @@ func GetSession(sessionId string) *Session {
 	return s
 }
 
+func setGauges() {
+	var ins float64
+	var cli float64
+
+	for _, s := range sessions {
+		ins += float64(len(s.Instances))
+		cli += float64(len(s.clients))
+	}
+
+	clientsGauge.Set(cli)
+	instancesGauge.Set(ins)
+	sessionsGauge.Set(float64(len(sessions)))
+}
+
 func LoadSessionsFromDisk() error {
 	file, err := os.Open("./pwd/sessions.gob")
 	if err == nil {
@@ -255,7 +285,6 @@ func LoadSessionsFromDisk() error {
 
 		// schedule session expiration
 		for _, s := range sessions {
-			sessionsGauge.Inc()
 			timeLeft := s.ExpiresAt.Sub(time.Now())
 			CloseSessionAfter(s, timeLeft)
 
@@ -263,7 +292,6 @@ func LoadSessionsFromDisk() error {
 			for _, i := range s.Instances {
 				// wire the session back to the instance
 				i.session = s
-				instancesGauge.Inc()
 			}
 
 			// Connect PWD daemon to the new network
@@ -278,6 +306,7 @@ func LoadSessionsFromDisk() error {
 		}
 	}
 	file.Close()
+	setGauges()
 	return err
 }