Added Prometheus metrics, don't forget to restrict access on /metrics endpoint.

cmd/rpdata-server/main.go

@@ -10,12 +10,14 @@ import (
 
 	"git.aiterp.net/rpdata/api/graph2"
 	"git.aiterp.net/rpdata/api/internal/auth"
+	"git.aiterp.net/rpdata/api/internal/instrumentation"
 	"git.aiterp.net/rpdata/api/internal/loader"
 	"git.aiterp.net/rpdata/api/internal/store"
 	"git.aiterp.net/rpdata/api/models"
 	"git.aiterp.net/rpdata/api/models/changes"
 	"git.aiterp.net/rpdata/api/models/logs"
 	"github.com/99designs/gqlgen/handler"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
 func main() {
@@ -24,9 +26,13 @@ func main() {
 		log.Fatalln("Failed to init store:", err)
 	}
 
+	instrumentation.Register()
+
 	http.Handle("/", handler.Playground("RPData API", "/graphql"))
 	http.Handle("/graphql", queryHandler())
 
+	http.Handle("/metrics", promhttp.Handler())
+
 	go func() {
 		err := logs.RunFullUpdate()
 		if err != nil {
@@ -81,6 +87,8 @@ func queryHandler() http.HandlerFunc {
 			return fmt.Errorf("The server failed to serve your request due to an internal error, it has been logged")
 		}),
 		handler.ComplexityLimit(300),
+		handler.RequestMiddleware(instrumentation.RequestMiddleware()),
+		handler.ResolverMiddleware(instrumentation.ResolverMiddleware()),
 	)
 
 	return func(w http.ResponseWriter, r *http.Request) {