TUN-1732: cloudflared metrics should track userHostnames

origin/metrics.go

@@ -57,6 +57,7 @@ type TunnelMetrics struct {
 
 	muxerMetrics        *muxerMetrics
 	tunnelsHA           tunnelsForHA
+	userHostnamesCounts *prometheus.CounterVec
 }
 
 func newMuxerMetrics() *muxerMetrics {
@@ -364,6 +365,15 @@ func NewTunnelMetrics() *TunnelMetrics {
 	)
 	prometheus.MustRegister(registerFail)
 
+	userHostnamesCounts := prometheus.NewCounterVec(
+		prometheus.CounterOpts{
+			Name: "user_hostnames_counts",
+			Help: "Which user hostnames cloudflared is serving",
+		},
+		[]string{"userHostname"},
+	)
+	prometheus.MustRegister(userHostnamesCounts)
+
 	registerSuccess := prometheus.NewCounter(
 		prometheus.CounterOpts{
 			Name: "tunnel_register_success",
@@ -389,6 +399,7 @@ func NewTunnelMetrics() *TunnelMetrics {
 		regSuccess:                     registerSuccess,
 		regFail:                        registerFail,
 		rpcFail:                        rpcFail,
+		userHostnamesCounts:            userHostnamesCounts,
 	}
 }
 

origin/tunnel.go

@@ -396,6 +396,8 @@ func RegisterTunnel(
 		}
 	}
 
+	config.Metrics.userHostnamesCounts.WithLabelValues(registration.Url).Inc()
+
 	config.Logger.Infof("Route propagating, it may take up to 1 minute for your new route to become functional")
 	return nil
 }