feat: add prometheus metrics without external standalone exporter

routes/api/metrics.go

@@ -0,0 +1,208 @@
+package api
+
+import (
+	"github.com/emvi/logbuch"
+	"github.com/gorilla/mux"
+	conf "github.com/muety/wakapi/config"
+	"github.com/muety/wakapi/middlewares"
+	"github.com/muety/wakapi/models"
+	v1 "github.com/muety/wakapi/models/compat/wakatime/v1"
+	mm "github.com/muety/wakapi/models/metrics"
+	"github.com/muety/wakapi/services"
+	"github.com/muety/wakapi/utils"
+	"net/http"
+	"sort"
+	"strconv"
+	"time"
+)
+
+const (
+	MetricsPrefix = "wakatime"
+
+	DescAllTime          = "Total seconds (all time)."
+	DescTotal            = "Total seconds."
+	DescEditors          = "Total seconds for each editor."
+	DescProjects         = "Total seconds for each project."
+	DescLanguages        = "Total seconds for each language."
+	DescOperatingSystems = "Total seconds for each operating system."
+	DescMachines         = "Total seconds for each machine."
+
+	DescAdminTotalTime       = "Total seconds (all users, all time)"
+	DescAdminTotalHeartbeats = "Total number of tracked heartbeats (all users, all time)"
+	DescAdminTotalUser       = "Total number of registered users"
+)
+
+type MetricsHandler struct {
+	config        *conf.Config
+	userSrvc      services.IUserService
+	summarySrvc   services.ISummaryService
+	heartbeatSrvc services.IHeartbeatService
+	keyValueSrvc  services.IKeyValueService
+}
+
+func NewMetricsHandler(userService services.IUserService, summaryService services.ISummaryService, heartbeatService services.IHeartbeatService, keyValueService services.IKeyValueService) *MetricsHandler {
+	return &MetricsHandler{
+		userSrvc:      userService,
+		summarySrvc:   summaryService,
+		heartbeatSrvc: heartbeatService,
+		keyValueSrvc:  keyValueService,
+		config:        conf.Get(),
+	}
+}
+
+func (h *MetricsHandler) RegisterRoutes(router *mux.Router) {
+	if !h.config.Security.ExposeMetrics {
+		return
+	}
+
+	logbuch.Info("exposing prometheus metrics under /api/metrics")
+
+	r := router.PathPrefix("/metrics").Subrouter()
+	r.Use(
+		middlewares.NewAuthenticateMiddleware(h.userSrvc).Handler,
+	)
+	r.Methods(http.MethodGet).HandlerFunc(h.Get)
+}
+
+func (h *MetricsHandler) Get(w http.ResponseWriter, r *http.Request) {
+	var metrics mm.Metrics
+
+	user := r.Context().Value(models.UserKey).(*models.User)
+	if user == nil {
+		w.WriteHeader(http.StatusUnauthorized)
+		return
+	}
+
+	summaryAllTime, err := h.summarySrvc.Aliased(time.Time{}, time.Now(), user, h.summarySrvc.Retrieve)
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+
+	from, to := utils.MustResolveIntervalRaw("today")
+
+	summaryToday, err := h.summarySrvc.Aliased(from, to, user, h.summarySrvc.Retrieve)
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		return
+	}
+
+	// User Metrics
+
+	metrics = append(metrics, &mm.CounterMetric{
+		Name:   MetricsPrefix + "_cumulative_seconds_total",
+		Desc:   DescAllTime,
+		Value:  int(v1.NewAllTimeFrom(summaryAllTime, &models.Filters{}).Data.TotalSeconds),
+		Labels: []mm.Label{},
+	})
+
+	metrics = append(metrics, &mm.CounterMetric{
+		Name:   MetricsPrefix + "_seconds_total",
+		Desc:   DescTotal,
+		Value:  int(summaryToday.TotalTime().Seconds()),
+		Labels: []mm.Label{},
+	})
+
+	for _, p := range summaryToday.Projects {
+		metrics = append(metrics, &mm.CounterMetric{
+			Name:   MetricsPrefix + "_project_seconds_total",
+			Desc:   DescProjects,
+			Value:  int(summaryToday.TotalTimeByKey(models.SummaryProject, p.Key).Seconds()),
+			Labels: []mm.Label{{Key: "name", Value: p.Key}},
+		})
+	}
+
+	for _, l := range summaryToday.Languages {
+		metrics = append(metrics, &mm.CounterMetric{
+			Name:   MetricsPrefix + "_language_seconds_total",
+			Desc:   DescLanguages,
+			Value:  int(summaryToday.TotalTimeByKey(models.SummaryLanguage, l.Key).Seconds()),
+			Labels: []mm.Label{{Key: "name", Value: l.Key}},
+		})
+	}
+
+	for _, e := range summaryToday.Editors {
+		metrics = append(metrics, &mm.CounterMetric{
+			Name:   MetricsPrefix + "_editor_seconds_total",
+			Desc:   DescEditors,
+			Value:  int(summaryToday.TotalTimeByKey(models.SummaryEditor, e.Key).Seconds()),
+			Labels: []mm.Label{{Key: "name", Value: e.Key}},
+		})
+	}
+
+	for _, o := range summaryToday.OperatingSystems {
+		metrics = append(metrics, &mm.CounterMetric{
+			Name:   MetricsPrefix + "_operating_system_seconds_total",
+			Desc:   DescOperatingSystems,
+			Value:  int(summaryToday.TotalTimeByKey(models.SummaryOS, o.Key).Seconds()),
+			Labels: []mm.Label{{Key: "name", Value: o.Key}},
+		})
+	}
+
+	for _, m := range summaryToday.Machines {
+		metrics = append(metrics, &mm.CounterMetric{
+			Name:   MetricsPrefix + "_machine_seconds_total",
+			Desc:   DescMachines,
+			Value:  int(summaryToday.TotalTimeByKey(models.SummaryMachine, m.Key).Seconds()),
+			Labels: []mm.Label{{Key: "name", Value: m.Key}},
+		})
+	}
+
+	// Admin metrics
+
+	if user.IsAdmin {
+		var (
+			totalSeconds    int
+			totalUsers      int
+			totalHeartbeats int
+		)
+
+		if t, err := h.keyValueSrvc.GetString(conf.KeyLatestTotalTime); err == nil && t != nil && t.Value != "" {
+			if d, err := time.ParseDuration(t.Value); err == nil {
+				totalSeconds = int(d.Seconds())
+			}
+		}
+
+		if t, err := h.keyValueSrvc.GetString(conf.KeyLatestTotalUsers); err == nil && t != nil && t.Value != "" {
+			if d, err := strconv.Atoi(t.Value); err == nil {
+				totalUsers = d
+			}
+		}
+
+		if t, err := h.keyValueSrvc.GetString(conf.KeyLatestTotalUsers); err == nil && t != nil && t.Value != "" {
+			if d, err := strconv.Atoi(t.Value); err == nil {
+				totalUsers = d
+			}
+		}
+
+		if t, err := h.heartbeatSrvc.Count(); err == nil {
+			totalHeartbeats = int(t)
+		}
+
+		metrics = append(metrics, &mm.CounterMetric{
+			Name:   MetricsPrefix + "_admin_seconds_total",
+			Desc:   DescAdminTotalTime,
+			Value:  totalSeconds,
+			Labels: []mm.Label{},
+		})
+
+		metrics = append(metrics, &mm.CounterMetric{
+			Name:   MetricsPrefix + "_admin_users_total",
+			Desc:   DescAdminTotalUser,
+			Value:  totalUsers,
+			Labels: []mm.Label{},
+		})
+
+		metrics = append(metrics, &mm.CounterMetric{
+			Name:   MetricsPrefix + "_admin_heartbeats_total",
+			Desc:   DescAdminTotalHeartbeats,
+			Value:  totalHeartbeats,
+			Labels: []mm.Label{},
+		})
+	}
+
+	sort.Sort(metrics)
+
+	w.Header().Set("content-type", "text/plain; charset=utf-8")
+	w.Write([]byte(metrics.Print()))
+}