metrics infrastructure iteration (#74, #76)

endpoints/frontend/config.go

@@ -3,19 +3,28 @@ package frontend
 import (
 	"github.com/michaelquigley/cf"
 	"github.com/pkg/errors"
+	"time"
 )
 
 type Config struct {
 	Identity  string
-	MetricsService string
+	Metrics   *MetricsConfig
 	Address   string
 	HostMatch string
 }
 
+type MetricsConfig struct {
+	Service        string
+	DropoutTimeout time.Duration
+}
+
 func DefaultConfig() *Config {
 	return &Config{
 		Identity: "frontend",
-		MetricsService: "metrics",
+		Metrics: &MetricsConfig{
+			Service:        "metrics",
+			DropoutTimeout: 30 * time.Second,
+		},
 		Address: "0.0.0.0:8080",
 	}
 }

endpoints/frontend/http.go

@@ -28,7 +28,7 @@ type httpListen struct {
 }
 
 func NewHTTP(cfg *Config) (*httpListen, error) {
-	ma, err := newMetricsAgent(cfg.Identity, cfg.MetricsService)
+	ma, err := newMetricsAgent(cfg)
 	if err != nil {
 		return nil, err
 	}

endpoints/frontend/metrics.go

@@ -12,7 +12,7 @@ import (
 )
 
 type metricsAgent struct {
-	metricsServiceName string
+	cfg     *Config
 	metrics *model.Metrics
 	updates chan metricsUpdate
 	zCtx    ziti.Context
@@ -24,19 +24,19 @@ type metricsUpdate struct {
 	bytesWritten int64
 }
 
-func newMetricsAgent(identityName, metricsServiceName string) (*metricsAgent, error) {
-	zif, err := zrokdir.ZitiIdentityFile(identityName)
+func newMetricsAgent(cfg *Config) (*metricsAgent, error) {
+	zif, err := zrokdir.ZitiIdentityFile(cfg.Identity)
 	if err != nil {
-		return nil, errors.Wrapf(err, "error getting '%v' identity file", identityName)
+		return nil, errors.Wrapf(err, "error getting '%v' identity file", cfg.Identity)
 	}
 	zCfg, err := config.NewFromFile(zif)
 	if err != nil {
-		return nil, errors.Wrapf(err, "error loading '%v' identity", identityName)
+		return nil, errors.Wrapf(err, "error loading '%v' identity", cfg.Identity)
 	}
-	logrus.Infof("loaded '%v' identity", identityName)
+	logrus.Infof("loaded '%v' identity", cfg.Identity)
 	return &metricsAgent{
-		metricsServiceName: metricsServiceName,
-		metrics:            &model.Metrics{Namespace: identityName},
+		cfg:     cfg,
+		metrics: &model.Metrics{Namespace: cfg.Identity},
 		updates: make(chan metricsUpdate, 10240),
 		zCtx:    ziti.NewContextWithConfig(zCfg),
 	}, nil
@@ -56,6 +56,16 @@ func (ma *metricsAgent) run() {
 			if err := ma.sendMetrics(); err != nil {
 				logrus.Errorf("error sending metrics: %v", err)
 			}
+			var dropouts []string
+			for k, v := range ma.metrics.Sessions {
+				if time.Now().Sub(time.UnixMilli(v.LastUpdate)) > ma.cfg.Metrics.DropoutTimeout {
+					dropouts = append(dropouts, k)
+				}
+			}
+			for _, dropout := range dropouts {
+				delete(ma.metrics.Sessions, dropout)
+				logrus.Infof("dropout: %v", dropout)
+			}
 		}
 	}
 }
@@ -66,7 +76,7 @@ func (ma *metricsAgent) sendMetrics() error {
 	if err != nil {
 		return errors.Wrap(err, "error marshaling metrics")
 	}
-	conn, err := ma.zCtx.Dial(ma.metricsServiceName)
+	conn, err := ma.zCtx.Dial(ma.cfg.Metrics.Service)
 	if err != nil {
 		return errors.Wrap(err, "error connecting to metrics service")
 	}