feat: add metric for login requests

co-authored-by: Vegar Sechmann Molvig <[email protected]>

Author: christeredvartsen

pkg/apiserver/api/device.go

@@ -133,6 +133,12 @@ func (s *grpcServer) UserGateways(ctx context.Context, userGroups []string) ([]*
 }
 
 func (s *grpcServer) Login(ctx context.Context, r *pb.APIServerLoginRequest) (*pb.APIServerLoginResponse, error) {
+	version := r.Version
+	if version == "" {
+		version = "unknown"
+	}
+	apiserver_metrics.LoginRequests.WithLabelValues(version).Inc()
+
 	session, err := s.authenticator.Login(ctx, r.Token, r.Serial, r.Platform)
 	if err != nil {
 		return nil, status.Errorf(codes.Unauthenticated, "login: %v", err)

pkg/apiserver/metrics/metrics.go

@@ -12,6 +12,7 @@ var (
 	DevicesConnected          prometheus.Gauge
 	GatewayConfigsReturned    *prometheus.CounterVec
 	PrivilegedUsersPerGateway *prometheus.GaugeVec
+	LoginRequests             *prometheus.CounterVec
 
 	gatewayStatus *prometheus.GaugeVec
 )
@@ -71,11 +72,19 @@ func init() {
 		Help:      "Total number of configs returned to gateway since apiserver started.",
 	}, []string{"gateway"})
 
+	LoginRequests = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Namespace: "naisdevice",
+		Subsystem: "apiserver",
+		Name:      "device_login_requests",
+		Help:      "Device logins with agent version.",
+	}, []string{"version"})
+
 	prometheus.MustRegister(
 		DevicesConnected,
 		gatewayStatus,
 		PrivilegedUsersPerGateway,
 		DeviceConfigsReturned,
 		GatewayConfigsReturned,
+		LoginRequests,
 	)
 }