Merge pull request #4691 from filecoin-project/fix/metrics

fix metrics wiring.

cmd/lotus/daemon.go

@@ -16,6 +16,7 @@ import (
 	"strings"
 
 	paramfetch "github.com/filecoin-project/go-paramfetch"
+	metricsprom "github.com/ipfs/go-metrics-prometheus"
 	"github.com/mitchellh/go-homedir"
 	"github.com/multiformats/go-multiaddr"
 	"github.com/urfave/cli/v2"
@@ -262,8 +263,14 @@ var DaemonCmd = &cli.Command{
 			liteModeDeps = node.Override(new(api.GatewayAPI), gapi)
 		}
 
-		var api api.FullNode
+		// some libraries like ipfs/go-ds-measure and ipfs/go-ipfs-blockstore
+		// use ipfs/go-metrics-interface. This injects a Prometheus exporter
+		// for those. Metrics are exported to the default registry.
+		if err := metricsprom.Inject(); err != nil {
+			log.Warnf("unable to inject prometheus ipfs/go-metrics exporter; some metrics will be unavailable; err: %s", err)
+		}
 
+		var api api.FullNode
 		stop, err := node.New(ctx,
 			node.FullAPI(&api, node.Lite(isLite)),
 

cmd/lotus/rpc.go

@@ -14,6 +14,7 @@ import (
 	logging "github.com/ipfs/go-log/v2"
 	"github.com/multiformats/go-multiaddr"
 	manet "github.com/multiformats/go-multiaddr/net"
+	promclient "github.com/prometheus/client_golang/prometheus"
 	"go.opencensus.io/tag"
 	"golang.org/x/xerrors"
 
@@ -49,7 +50,16 @@ func serveRPC(a api.FullNode, stop node.StopFunc, addr multiaddr.Multiaddr, shut
 
 	http.Handle("/rest/v0/import", importAH)
 
+	// Prometheus globals are exposed as interfaces, but the prometheus
+	// OpenCensus exporter expects a concrete *Registry. The concrete type of
+	// the globals are actually *Registry, so we downcast them, staying
+	// defensive in case things change under the hood.
+	registry, ok := promclient.DefaultRegisterer.(*promclient.Registry)
+	if !ok {
+		log.Warnf("failed to export default prometheus registry; some metrics will be unavailable; unexpected type: %T", promclient.DefaultRegisterer)
+	}
 	exporter, err := prometheus.NewExporter(prometheus.Options{
+		Registry:  registry,
 		Namespace: "lotus",
 	})
 	if err != nil {

go.mod

@@ -81,6 +81,7 @@ require (
 	github.com/ipfs/go-log v1.0.4
 	github.com/ipfs/go-log/v2 v2.1.2-0.20200626104915-0016c0b4b3e4
 	github.com/ipfs/go-merkledag v0.3.2
+	github.com/ipfs/go-metrics-interface v0.0.1
 	github.com/ipfs/go-metrics-prometheus v0.0.2
 	github.com/ipfs/go-path v0.0.7
 	github.com/ipfs/go-unixfs v0.2.4

node/builder.go

@@ -5,6 +5,8 @@ import (
 	"errors"
 	"time"
 
+	metricsi "github.com/ipfs/go-metrics-interface"
+
 	"github.com/filecoin-project/lotus/chain"
 	"github.com/filecoin-project/lotus/chain/exchange"
 	"github.com/filecoin-project/lotus/chain/store"
@@ -167,7 +169,10 @@ func defaults() []Option {
 		Override(new(journal.DisabledEvents), journal.EnvDisabledEvents),
 		Override(new(journal.Journal), modules.OpenFilesystemJournal),
 
-		Override(new(helpers.MetricsCtx), context.Background),
+		Override(new(helpers.MetricsCtx), func() context.Context {
+			return metricsi.CtxScope(context.Background(), "lotus")
+		}),
+
 		Override(new(record.Validator), modules.RecordValidator),
 		Override(new(dtypes.Bootstrapper), dtypes.Bootstrapper(false)),
 		Override(new(dtypes.ShutdownChan), make(chan struct{})),