Viewer metrics api (#208)

* Add support for ending the inbound stream. Closes #191

* Add a simple success response to API requests

* Add viewers over time API

* Move controllers to admin directory

controllers/admin/serverConfig.go

@@ -1,4 +1,4 @@
-package controllers
+package admin
 
 import (
 	"encoding/json"

controllers/admin/viewers.go

@@ -0,0 +1,15 @@
+package admin
+
+import (
+	"encoding/json"
+	"net/http"
+
+	"github.com/gabek/owncast/metrics"
+)
+
+// GetViewersOverTime will return the number of viewers at points in time
+func GetViewersOverTime(w http.ResponseWriter, r *http.Request) {
+	viewersOverTime := metrics.Metrics.Viewers
+	w.Header().Set("Content-Type", "application/json")
+	json.NewEncoder(w).Encode(viewersOverTime)
+}

metrics/alerting.go

@@ -36,6 +36,6 @@ func handleRAMAlerting() {
 	}
 }
 
-func recentAverage(values []value) int {
+func recentAverage(values []timestampedValue) int {
 	return int((values[len(values)-1].Value + values[len(values)-2].Value) / 2)
 }

metrics/hardware.go

@@ -20,7 +20,7 @@ func collectCPUUtilization() {
 		panic(err)
 	}
 
-	metricValue := value{time.Now(), int(v[0])}
+	metricValue := timestampedValue{time.Now(), int(v[0])}
 	Metrics.CPUUtilizations = append(Metrics.CPUUtilizations, metricValue)
 }
 
@@ -30,6 +30,6 @@ func collectRAMUtilization() {
 	}
 
 	memoryUsage, _ := mem.VirtualMemory()
-	metricValue := value{time.Now(), int(memoryUsage.UsedPercent)}
+	metricValue := timestampedValue{time.Now(), int(memoryUsage.UsedPercent)}
 	Metrics.RAMUtilizations = append(Metrics.RAMUtilizations, metricValue)
 }

metrics/metrics.go

@@ -7,14 +7,10 @@ import (
 // How often we poll for updates
 const metricsPollingInterval = 15 * time.Second
 
-type value struct {
-	Time  time.Time
-	Value int
-}
-
 type metrics struct {
-	CPUUtilizations []value
+	CPUUtilizations []timestampedValue
-	RAMUtilizations []value
+	RAMUtilizations []timestampedValue
+	Viewers         []timestampedValue
 }
 
 // Metrics is the shared Metrics instance
@@ -23,6 +19,7 @@ var Metrics *metrics
 // Start will begin the metrics collection and alerting
 func Start() {
 	Metrics = new(metrics)
+	startViewerCollectionMetrics()
 
 	for range time.Tick(metricsPollingInterval) {
 		handlePolling()

metrics/timestampedValue.go

@@ -0,0 +1,8 @@
+package metrics
+
+import "time"
+
+type timestampedValue struct {
+	Time  time.Time `json:"time"`
+	Value int       `json:"value"`
+}

metrics/viewers.go

@@ -0,0 +1,31 @@
+package metrics
+
+import (
+	"time"
+
+	"github.com/gabek/owncast/core"
+)
+
+// How often we poll for updates
+const viewerMetricsPollingInterval = 5 * time.Minute
+
+func startViewerCollectionMetrics() {
+	collectViewerCount()
+
+	for range time.Tick(viewerMetricsPollingInterval) {
+		collectViewerCount()
+	}
+}
+
+func collectViewerCount() {
+	if len(Metrics.Viewers) > maxCollectionValues {
+		Metrics.Viewers = Metrics.Viewers[1:]
+	}
+
+	count := core.GetStatus().ViewerCount
+	value := timestampedValue{
+		Value: count,
+		Time:  time.Now(),
+	}
+	Metrics.Viewers = append(Metrics.Viewers, value)
+}

router/router.go

@@ -58,7 +58,10 @@ func Start() error {
 	http.HandleFunc("/api/admin/changekey", middleware.RequireAdminAuth(admin.ChangeStreamKey))
 
 	// Server config
-	http.HandleFunc("/api/admin/serverconfig", middleware.RequireAdminAuth(controllers.GetServerConfig))
+	http.HandleFunc("/api/admin/serverconfig", middleware.RequireAdminAuth(admin.GetServerConfig))
+
+	// Get viewer count over time
+	http.HandleFunc("/api/admin/viewersOverTime", middleware.RequireAdminAuth(admin.GetViewersOverTime))
 
 	port := config.Config.GetPublicWebServerPort()