Expose usage stats under /status/usage-stats

cmd/tempo/app/modules.go

@@ -2,8 +2,10 @@ package app
 
 import (
 	"fmt"
+	"io"
 	"net/http"
 	"path"
+	"time"
 
 	"github.com/go-kit/log/level"
 	"github.com/grafana/dskit/kv/codec"
@@ -257,6 +259,9 @@ func (t *App) initQueryFrontend() (services.Service, error) {
 	// http query echo endpoint
 	t.Server.HTTP.Handle(addHTTPAPIPrefix(&t.cfg, api.PathEcho), echoHandler())
 
+	// http endpoint to see usage stats data
+	t.Server.HTTP.Handle(addHTTPAPIPrefix(&t.cfg, api.PathUsageStats), usageStatsHandler(t.usageReport, t.cfg.UsageReport))
+
 	// todo: queryFrontend should implement service.Service and take the cortex frontend a submodule
 	return t.frontend, nil
 }
@@ -447,3 +452,25 @@ func echoHandler() http.HandlerFunc {
 		http.Error(w, "echo", http.StatusOK)
 	}
 }
+
+func usageStatsHandler(usageReport *usagestats.Reporter, urCfg usagestats.Config) http.HandlerFunc {
+	if !urCfg.Enabled {
+		return func(w http.ResponseWriter, r *http.Request) {
+			http.Error(w, "usage-stats is not enabled", http.StatusOK)
+		}
+	}
+
+	// usage stats is Enabled, build and return usage stats json
+	report, err := usageReport.ReportJSON(time.Now())
+	if err != nil {
+		return func(w http.ResponseWriter, r *http.Request) {
+			http.Error(w, "error building usage report", http.StatusInternalServerError)
+		}
+	}
+
+	return func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		w.Header().Set("Content-Type", "application/json")
+		_, _ = io.WriteString(w, report)
+	}
+}

pkg/api/http.go

@@ -58,6 +58,7 @@ const (
 	PathSearchTags      = "/api/search/tags"
 	PathSearchTagValues = "/api/search/tag/{tagName}/values"
 	PathEcho            = "/api/echo"
+	PathUsageStats      = "/status/usage-stats"
 
 	QueryModeKey       = "mode"
 	QueryModeIngesters = "ingesters"

pkg/usagestats/stats.go

@@ -46,6 +46,7 @@ type Report struct {
 
 // sendReport sends the report to the stats server
 func sendReport(ctx context.Context, seed *ClusterSeed, interval time.Time) error {
+	// make buildReport func on ??
 	report := buildReport(seed, interval)
 	out, err := jsoniter.MarshalIndent(report, "", " ")
 	if err != nil {
@@ -167,7 +168,7 @@ func NewFloat(name string) *expvar.Float {
 }
 
 // NewInt returns a new Int stats object.
-// If an Int stats object object with the same name already exists it is returned.
+// If an Int stats object with the same name already exists it is returned.
 func NewInt(name string) *expvar.Int {
 	existing := expvar.Get(statsPrefix + name)
 	if existing != nil {
@@ -400,3 +401,9 @@ func (w *WordCounter) String() string {
 func (w *WordCounter) Value() int64 {
 	return w.count.Load()
 }
+
+func (rep *Reporter) ReportJSON(interval time.Time) (string, error) {
+	// FIXME: panic on boot here, please fix
+	report := buildReport(rep.cluster, interval)
+	return jsoniter.MarshalToString(report)
+}