Daily Active User Metrics (#3735)

* agent: add StatsReporter

* Stabilize protoc

coderd/coderd.go

@@ -30,6 +30,7 @@ import (
 	"github.com/coder/coder/coderd/gitsshkey"
 	"github.com/coder/coder/coderd/httpapi"
 	"github.com/coder/coder/coderd/httpmw"
+	"github.com/coder/coder/coderd/metricscache"
 	"github.com/coder/coder/coderd/rbac"
 	"github.com/coder/coder/coderd/telemetry"
 	"github.com/coder/coder/coderd/tracing"
@@ -76,6 +77,9 @@ type Options struct {
 	TailscaleEnable    bool
 	TailnetCoordinator *tailnet.Coordinator
 	DERPMap            *tailcfg.DERPMap
+
+	MetricsCacheRefreshInterval time.Duration
+	AgentStatsRefreshInterval   time.Duration
 }
 
 // New constructs a Coder API handler.
@@ -121,6 +125,12 @@ func New(options *Options) *API {
 		panic(xerrors.Errorf("read site bin failed: %w", err))
 	}
 
+	metricsCache := metricscache.New(
+		options.Database,
+		options.Logger.Named("metrics_cache"),
+		options.MetricsCacheRefreshInterval,
+	)
+
 	r := chi.NewRouter()
 	api := &API{
 		Options:     options,
@@ -130,6 +140,7 @@ func New(options *Options) *API {
 			Authorizer: options.Authorizer,
 			Logger:     options.Logger,
 		},
+		metricsCache: metricsCache,
 	}
 	if options.TailscaleEnable {
 		api.workspaceAgentCache = wsconncache.New(api.dialWorkspaceAgentTailnet, 0)
@@ -147,6 +158,13 @@ func New(options *Options) *API {
 		httpmw.Recover(api.Logger),
 		httpmw.Logger(api.Logger),
 		httpmw.Prometheus(options.PrometheusRegistry),
+		// Build-Version is helpful for debugging.
+		func(next http.Handler) http.Handler {
+			return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+				w.Header().Add("Build-Version", buildinfo.Version())
+				next.ServeHTTP(w, r)
+			})
+		},
 	)
 
 	apps := func(r chi.Router) {
@@ -259,7 +277,7 @@ func New(options *Options) *API {
 				apiKeyMiddleware,
 				httpmw.ExtractTemplateParam(options.Database),
 			)
-
+			r.Get("/daus", api.templateDAUs)
 			r.Get("/", api.template)
 			r.Delete("/", api.deleteTemplate)
 			r.Patch("/", api.patchTemplateMeta)
@@ -359,11 +377,14 @@ func New(options *Options) *API {
 				r.Get("/metadata", api.workspaceAgentMetadata)
 				r.Post("/version", api.postWorkspaceAgentVersion)
 				r.Get("/listen", api.workspaceAgentListen)
+
 				r.Get("/gitsshkey", api.agentGitSSHKey)
 				r.Get("/turn", api.workspaceAgentTurn)
 				r.Get("/iceservers", api.workspaceAgentICEServers)
 
 				r.Get("/coordinate", api.workspaceAgentCoordinate)
+
+				r.Get("/report-stats", api.workspaceAgentReportStats)
 			})
 			r.Route("/{workspaceagent}", func(r chi.Router) {
 				r.Use(
@@ -452,6 +473,8 @@ type API struct {
 	websocketWaitGroup  sync.WaitGroup
 	workspaceAgentCache *wsconncache.Cache
 	httpAuth            *HTTPAuthorizer
+
+	metricsCache *metricscache.Cache
 }
 
 // Close waits for all WebSocket connections to drain before returning.
@@ -460,6 +483,8 @@ func (api *API) Close() error {
 	api.websocketWaitGroup.Wait()
 	api.websocketWaitMutex.Unlock()
 
+	api.metricsCache.Close()
+
 	return api.workspaceAgentCache.Close()
 }