More prometheus metrics

docker-compose.yml

@@ -39,5 +39,18 @@ services:
             - sessions:/pwd
         environment:
             GOOGLE_RECAPTCHA_DISABLED: "true"
+    prometheus:
+        container_name: prometheus
+        image: prom/prometheus
+        volumes:
+            - ./prometheus.yml:/etc/prometheus/prometheus.yml
+    grafana:
+        container_name: grafana
+        image: grafana/grafana
+        ports:
+            - "3000:3000"
+        volumes:
+            - grafana:/var/lib/grafana
 volumes:
     sessions:
+    grafana:

prometheus.yml

@@ -0,0 +1,24 @@
+# my global config
+global:
+  scrape_interval:     5s # Set the scrape interval to every 15 seconds. Default is every 1 minute.
+  evaluation_interval: 5s # Evaluate rules every 15 seconds. The default is every 1 minute.
+  # scrape_timeout is set to the global default (10s).
+
+  # Attach these labels to any time series or alerts when communicating with
+  # external systems (federation, remote storage, Alertmanager).
+# Load rules once and periodically evaluate them according to the global 'evaluation_interval'.
+rule_files:
+  # - "first.rules"
+  # - "second.rules"
+
+# A scrape configuration containing exactly one endpoint to scrape:
+# Here it's Prometheus itself.
+scrape_configs:
+  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
+  - job_name: 'pwd'
+
+    # metrics_path defaults to '/metrics'
+    # scheme defaults to 'http'.
+
+    static_configs:
+      - targets: ['pwd1:3000', 'pwd2:3000']

pwd/client.go

@@ -1,6 +1,9 @@
 package pwd
 
-import "log"
+import (
+	"log"
+	"time"
+)
 
 type Client struct {
 	Id       string
@@ -14,12 +17,14 @@ type ViewPort struct {
 }
 
 func (p *pwd) ClientNew(id string, session *Session) *Client {
+	defer observeAction("ClientNew", time.Now())
 	c := &Client{Id: id, session: session}
 	session.clients = append(session.clients, c)
 	return c
 }
 
 func (p *pwd) ClientResizeViewPort(c *Client, cols, rows uint) {
+	defer observeAction("ClientResizeViewPort", time.Now())
 	c.viewPort.Rows = rows
 	c.viewPort.Cols = cols
 
@@ -27,6 +32,7 @@ func (p *pwd) ClientResizeViewPort(c *Client, cols, rows uint) {
 }
 
 func (p *pwd) ClientClose(client *Client) {
+	defer observeAction("ClientClose", time.Now())
 	// Client has disconnected. Remove from session and recheck terminal sizes.
 	session := client.session
 	for i, cl := range session.clients {

pwd/instance.go

@@ -10,6 +10,7 @@ import (
 	"path/filepath"
 	"strings"
 	"sync"
+	"time"
 
 	"github.com/play-with-docker/play-with-docker/config"
 	"github.com/play-with-docker/play-with-docker/docker"
@@ -90,6 +91,7 @@ func (i *Instance) SetSession(s *Session) {
 }
 
 func (p *pwd) InstanceResizeTerminal(instance *Instance, rows, cols uint) error {
+	defer observeAction("InstanceResizeTerminal", time.Now())
 	return p.docker.ContainerResize(instance.Name, rows, cols)
 }
 
@@ -109,6 +111,7 @@ func (p *pwd) InstanceAttachTerminal(instance *Instance) error {
 }
 
 func (p *pwd) InstanceUploadFromUrl(instance *Instance, url string) error {
+	defer observeAction("InstanceUploadFromUrl", time.Now())
 	log.Printf("Downloading file [%s]\n", url)
 	resp, err := http.Get(url)
 	if err != nil {
@@ -131,10 +134,12 @@ func (p *pwd) InstanceUploadFromUrl(instance *Instance, url string) error {
 }
 
 func (p *pwd) InstanceGet(session *Session, name string) *Instance {
+	defer observeAction("InstanceGet", time.Now())
 	return session.Instances[name]
 }
 
 func (p *pwd) InstanceFindByIP(ip string) *Instance {
+	defer observeAction("InstanceFindByIP", time.Now())
 	for _, s := range sessions {
 		for _, i := range s.Instances {
 			if i.IP == ip {
@@ -146,6 +151,7 @@ func (p *pwd) InstanceFindByIP(ip string) *Instance {
 }
 
 func (p *pwd) InstanceFindByAlias(sessionPrefix, alias string) *Instance {
+	defer observeAction("InstanceFindByAlias", time.Now())
 	for id, s := range sessions {
 		if strings.HasPrefix(id, sessionPrefix) {
 			for _, i := range s.Instances {
@@ -159,6 +165,7 @@ func (p *pwd) InstanceFindByAlias(sessionPrefix, alias string) *Instance {
 }
 
 func (p *pwd) InstanceDelete(session *Session, instance *Instance) error {
+	defer observeAction("InstanceDelete", time.Now())
 	if instance.conn != nil {
 		instance.conn.Close()
 	}
@@ -193,6 +200,7 @@ func (p *pwd) checkHostnameExists(session *Session, hostname string) bool {
 }
 
 func (p *pwd) InstanceNew(session *Session, conf InstanceConfig) (*Instance, error) {
+	defer observeAction("InstanceNew", time.Now())
 	session.rw.Lock()
 	defer session.rw.Unlock()
 
@@ -274,12 +282,14 @@ func (p *pwd) InstanceNew(session *Session, conf InstanceConfig) (*Instance, err
 }
 
 func (p *pwd) InstanceWriteToTerminal(instance *Instance, data string) {
+	defer observeAction("InstanceWriteToTerminal", time.Now())
 	if instance != nil && instance.conn != nil && len(data) > 0 {
 		instance.conn.Write([]byte(data))
 	}
 }
 
 func (p *pwd) InstanceAllowedImages() []string {
+	defer observeAction("InstanceAllowedImages", time.Now())
 
 	return []string{
 		config.GetDindImageName(),
@@ -289,5 +299,6 @@ func (p *pwd) InstanceAllowedImages() []string {
 }
 
 func (p *pwd) InstanceExec(instance *Instance, cmd []string) (int, error) {
+	defer observeAction("InstanceExec", time.Now())
 	return p.docker.Exec(instance.Name, cmd)
 }

pwd/pwd.go

@@ -21,8 +21,18 @@ var (
 		Name: "instances",
 		Help: "Instances",
 	})
+
+	latencyHistogramVec = prometheus.NewHistogramVec(prometheus.HistogramOpts{
+		Name:    "pwd_action_duration_ms",
+		Help:    "How long it took to process a specific action, in a specific host",
+		Buckets: []float64{300, 1200, 5000},
+	}, []string{"action"})
 )
 
+func observeAction(action string, start time.Time) {
+	latencyHistogramVec.WithLabelValues(action).Observe(float64(time.Since(start).Nanoseconds()) / 1000000)
+}
+
 var sessions map[string]*Session
 var sessionsMutex sync.Mutex
 
@@ -30,6 +40,7 @@ func init() {
 	prometheus.MustRegister(sessionsGauge)
 	prometheus.MustRegister(clientsGauge)
 	prometheus.MustRegister(instancesGauge)
+	prometheus.MustRegister(latencyHistogramVec)
 
 	sessions = make(map[string]*Session)
 }

pwd/session.go

@@ -52,6 +52,8 @@ type Session struct {
 }
 
 func (p *pwd) SessionNew(duration time.Duration, stack, stackName string) (*Session, error) {
+	defer observeAction("SessionNew", time.Now())
+
 	sessionsMutex.Lock()
 	defer sessionsMutex.Unlock()
 
@@ -151,6 +153,7 @@ func (p *pwd) SessionGetSmallestViewPort(s *Session) ViewPort {
 }
 
 func (p *pwd) SessionDeployStack(s *Session) error {
+	defer observeAction("SessionDeployStack", time.Now())
 	if s.Ready {
 		// a stack was already deployed on this session, just ignore
 		return nil
@@ -190,11 +193,13 @@ func (p *pwd) SessionDeployStack(s *Session) error {
 }
 
 func (p *pwd) SessionGet(sessionId string) *Session {
+	defer observeAction("SessionGet", time.Now())
 	s := sessions[sessionId]
 	return s
 }
 
 func (p *pwd) SessionLoadAndPrepare() error {
+	defer observeAction("SessionLoadAndPrepare", time.Now())
 	err := p.storage.Load()
 	if err != nil {
 		return err
@@ -232,6 +237,7 @@ func (p *pwd) SessionLoadAndPrepare() error {
 }
 
 func (p *pwd) SessionSetup(session *Session, conf SessionSetupConf) error {
+	defer observeAction("SessionSetup", time.Now())
 	var tokens *docker.SwarmTokens = nil
 	var firstSwarmManager *Instance = nil