Merge pull request '#14 add workout counter' (#69) from 14-monitoring into master

Reviewed-on: tim/me-fit#69

api/src/workout/workout.go

@@ -10,10 +10,24 @@ import (
 	"time"
 
 	"firebase.google.com/go/auth"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var (
+	metrics = promauto.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "mefit_api_workout_total",
+			Help: "The total number of workout api requests processed",
+		},
+		[]string{"type"},
+	)
 )
 
 func NewWorkout(db *sql.DB) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
+		metrics.WithLabelValues("new").Inc()
+
 		var dateStr = r.FormValue("date")
 		var typeStr = r.FormValue("type")
 		var setsStr = r.FormValue("sets")
@@ -55,6 +69,8 @@ func NewWorkout(db *sql.DB) http.HandlerFunc {
 
 func GetWorkouts(db *sql.DB) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
+		metrics.WithLabelValues("get").Inc()
+
 		token := r.Context().Value(middleware.TOKEN_KEY).(*auth.Token)
 		var userId = token.UID
 
@@ -94,6 +110,8 @@ func GetWorkouts(db *sql.DB) http.HandlerFunc {
 
 func DeleteWorkout(db *sql.DB) http.HandlerFunc {
 	return func(w http.ResponseWriter, r *http.Request) {
+		metrics.WithLabelValues("delete").Inc()
+
 		token := r.Context().Value(middleware.TOKEN_KEY).(*auth.Token)
 		var userId = token.UID