metrics: f3: Set up otel metrics reporting to prometheus

CHANGELOG.md

@@ -7,6 +7,7 @@
 - https://github.com/filecoin-project/lotus/pull/12112: Moved consts from build/ to build/buildconstants/ for ligher curio deps.
 - https://github.com/filecoin-project/lotus/pull/12237: Upgrade to go-f3 `v0.0.4`.
 - https://github.com/filecoin-project/lotus/pull/12269 Fix `logIndex` ordering in `EthGetTransactionReceipt` by using the EventIndex to fetch logs
+- https://github.com/filecoin-project/lotus/pull/12285 Set up OpenTelemetry metrics reporting to prometheus
 
 ## ☢️ Upgrade Warnings ☢️
 

chain/lf3/f3.go

@@ -10,6 +10,9 @@ import (
 	logging "github.com/ipfs/go-log/v2"
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
 	"github.com/libp2p/go-libp2p/core/host"
+	"go.opentelemetry.io/otel"
+	"go.opentelemetry.io/otel/exporters/prometheus"
+	"go.opentelemetry.io/otel/sdk/metric"
 	"go.uber.org/fx"
 	"golang.org/x/xerrors"
 
@@ -50,6 +53,20 @@ type F3Params struct {
 
 var log = logging.Logger("f3")
 
+func init() {
+	// Set up otel to prometheus reporting so that F3 metrics are reported via lotus
+	// prometheus metrics. This bridge eventually gets picked up by opencensus
+	// exporter as HTTP handler. This by default registers an otel collector against
+	// the global prometheus registry. In the future, we should clean up metrics in
+	// Lotus and move it all to use otel. For now, bridge away.
+	if bridge, err := prometheus.New(); err != nil {
+		log.Errorf("could not create the otel prometheus exporter: %v", err)
+	} else {
+		provider := metric.NewMeterProvider(metric.WithReader(bridge))
+		otel.SetMeterProvider(provider)
+	}
+}
+
 func New(mctx helpers.MetricsCtx, lc fx.Lifecycle, params F3Params) (*F3, error) {
 
 	ds := namespace.Wrap(params.Datastore, datastore.NewKey("/f3"))

go.mod

@@ -144,7 +144,9 @@ require (
 	go.opentelemetry.io/otel v1.28.0
 	go.opentelemetry.io/otel/bridge/opencensus v1.28.0
 	go.opentelemetry.io/otel/exporters/jaeger v1.14.0
+	go.opentelemetry.io/otel/exporters/prometheus v0.50.0
 	go.opentelemetry.io/otel/sdk v1.28.0
+	go.opentelemetry.io/otel/sdk/metric v1.28.0
 	go.uber.org/atomic v1.11.0
 	go.uber.org/fx v1.22.1
 	go.uber.org/multierr v1.11.0
@@ -316,7 +318,6 @@ require (
 	github.com/zondax/hid v0.9.2 // indirect
 	github.com/zondax/ledger-go v0.14.3 // indirect
 	go.opentelemetry.io/otel/metric v1.28.0 // indirect
-	go.opentelemetry.io/otel/sdk/metric v1.28.0 // indirect
 	go.opentelemetry.io/otel/trace v1.28.0 // indirect
 	go.uber.org/dig v1.17.1 // indirect
 	go.uber.org/mock v0.4.0 // indirect

go.sum

@@ -1387,6 +1387,8 @@ go.opentelemetry.io/otel/bridge/opencensus v1.28.0 h1:/BcyAV1bUJjSVxoeKwTQL9cS4X
 go.opentelemetry.io/otel/bridge/opencensus v1.28.0/go.mod h1:FZp2xE+46yAyp3DfLFALze58nY0iIE8zs+mCgkPAzq0=
 go.opentelemetry.io/otel/exporters/jaeger v1.14.0 h1:CjbUNd4iN2hHmWekmOqZ+zSCU+dzZppG8XsV+A3oc8Q=
 go.opentelemetry.io/otel/exporters/jaeger v1.14.0/go.mod h1:4Ay9kk5vELRrbg5z4cpP9EtmQRFap2Wb0woPG4lujZA=
+go.opentelemetry.io/otel/exporters/prometheus v0.50.0 h1:2Ewsda6hejmbhGFyUvWZjUThC98Cf8Zy6g0zkIimOng=
+go.opentelemetry.io/otel/exporters/prometheus v0.50.0/go.mod h1:pMm5PkUo5YwbLiuEf7t2xg4wbP0/eSJrMxIMxKosynY=
 go.opentelemetry.io/otel/metric v1.28.0 h1:f0HGvSl1KRAU1DLgLGFjrwVyismPlnuU6JD6bOeuA5Q=
 go.opentelemetry.io/otel/metric v1.28.0/go.mod h1:Fb1eVBFZmLVTMb6PPohq3TO9IIhUisDsbJoL/+uQW4s=
 go.opentelemetry.io/otel/sdk v1.28.0 h1:b9d7hIry8yZsgtbmM0DKyPWMMUMlK9NEKuIG4aBqWyE=