node/pkg/p2p: add metric for guardian network heights

Change-Id: Ie09d203d316a448dba5d4ac9269113467e2da78e

bridge/pkg/p2p/netmetrics.go

@@ -0,0 +1,31 @@
+package p2p
+
+import (
+	gossipv1 "github.com/certusone/wormhole/bridge/pkg/proto/gossip/v1"
+	"github.com/certusone/wormhole/bridge/pkg/vaa"
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/libp2p/go-libp2p-core/peer"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+var (
+	wormholeNetworkNodeHeight = promauto.NewGaugeVec(
+		prometheus.GaugeOpts{
+			Name: "wormhole_network_node_height",
+			Help: "Network height of the given guardian node per network",
+		}, []string{"guardian_addr", "node_id", "node_name", "network"})
+)
+
+func collectNodeMetrics(addr common.Address, peerId peer.ID, hb *gossipv1.Heartbeat) {
+	for _, n := range hb.Networks {
+		if n == nil {
+			continue
+		}
+
+		chain := vaa.ChainID(n.Id)
+
+		wormholeNetworkNodeHeight.WithLabelValues(
+			addr.Hex(), peerId.Pretty(), hb.NodeName, chain.String()).Set(float64(n.Height))
+	}
+}

bridge/pkg/p2p/p2p.go

@@ -209,6 +209,7 @@ func Run(obsvC chan *gossipv1.SignedObservation, sendC chan []byte, rawHeartbeat
 					if err := gst.SetHeartbeat(ourAddr, h.ID(), heartbeat); err != nil {
 						panic(err)
 					}
+					collectNodeMetrics(ourAddr, h.ID(), heartbeat)
 
 					b, err := proto.Marshal(heartbeat)
 					if err != nil {
@@ -372,5 +373,7 @@ func processSignedHeartbeat(from peer.ID, s *gossipv1.SignedHeartbeat, gs *bridg
 		return nil, fmt.Errorf("failed to store in guardian set state: %w", err)
 	}
 
+	collectNodeMetrics(signerAddr, from, &h)
+
 	return &h, nil
 }