Add peer ping service and metrics

Author: ulope

rolling-shutter/p2p/dht.go

@@ -94,6 +94,10 @@ func findPeers(ctx context.Context, h host.Host, d discovery.Discoverer, ns stri
 					continue
 				}
 				metricsP2PPeerConnectedness.WithLabelValues(ourId, p.ID.String()).Add(float64(h.Network().Connectedness(p.ID)))
+				peerPing := h.Peerstore().LatencyEWMA(p.ID)
+				if peerPing != 0 {
+					metricsP2PPeerPing.WithLabelValues(ourId, p.ID.String()).Set(peerPing.Seconds())
+				}
 				if h.Network().Connectedness(p.ID) != network.Connected {
 					_, err = h.Network().DialPeer(ctx, p.ID)
 					if err != nil {

rolling-shutter/p2p/metrics.go

@@ -45,6 +45,16 @@ var metricsP2PPeerConnectedness = prometheus.NewGaugeVec(
 	},
 	[]string{"our_id", "peer_id"})
 
+var metricsP2PPeerPing = prometheus.NewGaugeVec(
+	prometheus.GaugeOpts{
+		Namespace: "shutter",
+		Subsystem: "p2p",
+		Name:      "peer_ping_time_seconds",
+		Help:      "Collection of the ping time to a peer ID.",
+	},
+	[]string{"our_id", "peer_id"},
+)
+
 func collectPeerAddresses(p peer.AddrInfo) {
 	for _, multiAddr := range p.Addrs {
 		metricsP2PPeerTuples.WithLabelValues(p.ID.String(), multiAddr.String()).Add(1)
@@ -56,4 +66,5 @@ func init() {
 	prometheus.MustRegister(metricsP2PMessageHandlingTime)
 	prometheus.MustRegister(metricsP2PPeerTuples)
 	prometheus.MustRegister(metricsP2PPeerConnectedness)
+	prometheus.MustRegister(metricsP2PPeerPing)
 }

rolling-shutter/p2p/p2p.go

@@ -200,6 +200,7 @@ func createHost(
 		libp2p.ListenAddrs(config.ListenAddrs...),
 		libp2p.ConnectionManager(connectionManager),
 		libp2p.ProtocolVersion(protocolVersion),
+		libp2p.Ping(true),
 	}
 
 	localNetworking := bool(config.Environment == env.EnvironmentLocal)