feat(dot/network): introduce libp2p resource manager + prometheus met…

…rics (#3333)

dot/network/host.go

@@ -26,7 +26,10 @@ import (
 	"github.com/libp2p/go-libp2p/core/peerstore"
 	"github.com/libp2p/go-libp2p/core/protocol"
 	"github.com/libp2p/go-libp2p/p2p/host/peerstore/pstoreds"
+	rm "github.com/libp2p/go-libp2p/p2p/host/resource-manager"
+	rmObs "github.com/libp2p/go-libp2p/p2p/host/resource-manager/obs"
 	ma "github.com/multiformats/go-multiaddr"
+	"github.com/prometheus/client_golang/prometheus"
 )
 
 func newPrivateIPFilters() (privateIPs *ma.Filters, err error) {
@@ -178,8 +181,27 @@ func newHost(ctx context.Context, cfg *Config) (*host, error) {
 		return nil, fmt.Errorf("failed to create peerstore: %w", err)
 	}
 
+	limiter := rm.NewFixedLimiter(rm.DefaultLimits.AutoScale())
+	var managerOptions []rm.Option
+
+	if cfg.Metrics.Publish {
+		rmObs.MustRegisterWith(prometheus.DefaultRegisterer)
+		reporter, err := rmObs.NewStatsTraceReporter()
+		if err != nil {
+			return nil, fmt.Errorf("while creating resource manager stats trace reporter: %w", err)
+		}
+
+		managerOptions = append(managerOptions, rm.WithTraceReporter(reporter))
+	}
+
+	manager, err := rm.NewResourceManager(limiter, managerOptions...)
+	if err != nil {
+		return nil, fmt.Errorf("while creating the resource manager: %w", err)
+	}
+
 	// set libp2p host options
 	opts := []libp2p.Option{
+		libp2p.ResourceManager(manager),
 		libp2p.ListenAddrs(addr),
 		libp2p.DisableRelay(),
 		libp2p.Identity(cfg.privateKey),