op-node: Document metrics

op-node/cmd/doc/cmd.go

+package doc
+
+import (
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/ethereum-optimism/optimism/op-node/metrics"
+	"github.com/olekukonko/tablewriter"
+	"github.com/urfave/cli"
+)
+
+var Subcommands = cli.Commands{
+	{
+		Name:  "metrics",
+		Usage: "Dumps a list of supported metrics to stdout",
+		Flags: []cli.Flag{
+			cli.StringFlag{
+				Name:  "format",
+				Value: "markdown",
+				Usage: "Output format (json|markdown)",
+			},
+		},
+		Action: func(ctx *cli.Context) error {
+			m := metrics.NewMetrics("default")
+			supportedMetrics := m.Document()
+			format := ctx.String("format")
+
+			if format != "markdown" && format != "json" {
+				return fmt.Errorf("invalid format: %s", format)
+			}
+
+			if format == "json" {
+				enc := json.NewEncoder(os.Stdout)
+				return enc.Encode(supportedMetrics)
+			}
+
+			table := tablewriter.NewWriter(os.Stdout)
+			table.SetBorders(tablewriter.Border{Left: true, Top: false, Right: true, Bottom: false})
+			table.SetCenterSeparator("|")
+			table.SetAutoWrapText(false)
+			table.SetHeader([]string{"Metric", "Description", "Labels", "Type"})
+			var data [][]string
+			for _, metric := range supportedMetrics {
+				labels := strings.Join(metric.Labels, ",")
+				data = append(data, []string{metric.Name, metric.Help, labels, metric.Type})
+			}
+			table.AppendBulk(data)
+			table.Render()
+			return nil
+		},
+	},
+}

op-node/cmd/main.go

@@ -9,6 +9,8 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/ethereum-optimism/optimism/op-node/cmd/doc"
+
 	"github.com/urfave/cli"
 
 	opnode "github.com/ethereum-optimism/optimism/op-node"
@@ -68,6 +70,10 @@ func main() {
 			Name:        "genesis",
 			Subcommands: genesis.Subcommands,
 		},
+		{
+			Name:        "doc",
+			Subcommands: doc.Subcommands,
+		},
 	}
 
 	err := app.Run(os.Args)

op-node/go.mod

@@ -23,6 +23,7 @@ require (
 	github.com/libp2p/go-libp2p-testing v0.12.0
 	github.com/multiformats/go-multiaddr v0.7.0
 	github.com/multiformats/go-multiaddr-dns v0.3.1
+	github.com/olekukonko/tablewriter v0.0.5
 	github.com/prometheus/client_golang v1.13.0
 	github.com/stretchr/testify v1.8.1
 	github.com/urfave/cli v1.22.9
@@ -115,7 +116,6 @@ require (
 	github.com/multiformats/go-multistream v0.3.3 // indirect
 	github.com/multiformats/go-varint v0.0.6 // indirect
 	github.com/nxadm/tail v1.4.8 // indirect
-	github.com/olekukonko/tablewriter v0.0.5 // indirect
 	github.com/onsi/ginkgo v1.16.5 // indirect
 	github.com/opencontainers/runtime-spec v1.0.2 // indirect
 	github.com/opentracing/opentracing-go v1.2.0 // indirect

op-node/metrics/caching.go

 package metrics
 
 import (
+	"github.com/ethereum-optimism/optimism/op-service/metrics"
 	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promauto"
 )
 
 // CacheMetrics implements the Metrics interface in the caching package,
@@ -34,16 +34,16 @@ func (m *CacheMetrics) CacheGet(typeLabel string, hit bool) {
 	}
 }
 
-func NewCacheMetrics(registry prometheus.Registerer, ns string, name string, displayName string) *CacheMetrics {
+func NewCacheMetrics(factory metrics.Factory, ns string, name string, displayName string) *CacheMetrics {
 	return &CacheMetrics{
-		SizeVec: promauto.With(registry).NewGaugeVec(prometheus.GaugeOpts{
+		SizeVec: factory.NewGaugeVec(prometheus.GaugeOpts{
 			Namespace: ns,
 			Name:      name + "_size",
 			Help:      displayName + " cache size",
 		}, []string{
 			"type",
 		}),
-		GetVec: promauto.With(registry).NewCounterVec(prometheus.CounterOpts{
+		GetVec: factory.NewCounterVec(prometheus.CounterOpts{
 			Namespace: ns,
 			Name:      name + "_get",
 			Help:      displayName + " lookups, hitting or not",
@@ -51,7 +51,7 @@ func NewCacheMetrics(registry prometheus.Registerer, ns string, name string, dis
 			"type",
 			"hit",
 		}),
-		AddVec: promauto.With(registry).NewCounterVec(prometheus.CounterOpts{
+		AddVec: factory.NewCounterVec(prometheus.CounterOpts{
 			Namespace: ns,
 			Name:      name + "_add",
 			Help:      displayName + " additions, evicting previous values or not",

op-node/metrics/events.go

@@ -4,8 +4,9 @@ import (
 	"fmt"
 	"time"
 
+	"github.com/ethereum-optimism/optimism/op-service/metrics"
+
 	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promauto"
 )
 
 type EventMetrics struct {
@@ -18,14 +19,14 @@ func (e *EventMetrics) RecordEvent() {
 	e.LastTime.Set(float64(time.Now().Unix()))
 }
 
-func NewEventMetrics(registry prometheus.Registerer, ns string, name string, displayName string) *EventMetrics {
+func NewEventMetrics(factory metrics.Factory, ns string, name string, displayName string) *EventMetrics {
 	return &EventMetrics{
-		Total: promauto.With(registry).NewCounter(prometheus.CounterOpts{
+		Total: factory.NewCounter(prometheus.CounterOpts{
 			Namespace: ns,
 			Name:      fmt.Sprintf("%s_total", name),
 			Help:      fmt.Sprintf("Count of %s events", displayName),
 		}),
-		LastTime: promauto.With(registry).NewGauge(prometheus.GaugeOpts{
+		LastTime: factory.NewGauge(prometheus.GaugeOpts{
 			Namespace: ns,
 			Name:      fmt.Sprintf("last_%s_unix", name),
 			Help:      fmt.Sprintf("Timestamp of last %s event", displayName),

op-service/metrics/factory.go

+package metrics
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promauto"
+)
+
+type Factory interface {
+	NewCounter(opts prometheus.CounterOpts) prometheus.Counter
+	NewCounterVec(opts prometheus.CounterOpts, labelNames []string) *prometheus.CounterVec
+	NewGauge(opts prometheus.GaugeOpts) prometheus.Gauge
+	NewGaugeVec(opts prometheus.GaugeOpts, labelNames []string) *prometheus.GaugeVec
+	NewHistogram(opts prometheus.HistogramOpts) prometheus.Histogram
+	NewHistogramVec(opts prometheus.HistogramOpts, labelNames []string) *prometheus.HistogramVec
+	NewSummary(opts prometheus.SummaryOpts) prometheus.Summary
+	NewSummaryVec(opts prometheus.SummaryOpts, labelNames []string) *prometheus.SummaryVec
+	Document() []DocumentedMetric
+}
+
+type DocumentedMetric struct {
+	Type   string   `json:"type"`
+	Name   string   `json:"name"`
+	Help   string   `json:"help"`
+	Labels []string `json:"labels"`
+}
+
+type documentor struct {
+	metrics []DocumentedMetric
+	factory promauto.Factory
+}
+
+func With(registry *prometheus.Registry) Factory {
+	return &documentor{
+		factory: promauto.With(registry),
+	}
+}
+
+func (d *documentor) NewCounter(opts prometheus.CounterOpts) prometheus.Counter {
+	d.metrics = append(d.metrics, DocumentedMetric{
+		Type: "counter",
+		Name: fullName(opts.Namespace, opts.Subsystem, opts.Name),
+		Help: opts.Help,
+	})
+	return d.factory.NewCounter(opts)
+}
+
+func (d *documentor) NewCounterVec(opts prometheus.CounterOpts, labelNames []string) *prometheus.CounterVec {
+	d.metrics = append(d.metrics, DocumentedMetric{
+		Type:   "counter",
+		Name:   fullName(opts.Namespace, opts.Subsystem, opts.Name),
+		Help:   opts.Help,
+		Labels: labelNames,
+	})
+	return d.factory.NewCounterVec(opts, labelNames)
+}
+
+func (d *documentor) NewGauge(opts prometheus.GaugeOpts) prometheus.Gauge {
+	d.metrics = append(d.metrics, DocumentedMetric{
+		Type: "gauge",
+		Name: fullName(opts.Namespace, opts.Subsystem, opts.Name),
+		Help: opts.Help,
+	})
+	return d.factory.NewGauge(opts)
+}
+
+func (d *documentor) NewGaugeVec(opts prometheus.GaugeOpts, labelNames []string) *prometheus.GaugeVec {
+	d.metrics = append(d.metrics, DocumentedMetric{
+		Type:   "gauge",
+		Name:   fullName(opts.Namespace, opts.Subsystem, opts.Name),
+		Help:   opts.Help,
+		Labels: labelNames,
+	})
+	return d.factory.NewGaugeVec(opts, labelNames)
+}
+
+func (d *documentor) NewHistogram(opts prometheus.HistogramOpts) prometheus.Histogram {
+	d.metrics = append(d.metrics, DocumentedMetric{
+		Type: "histogram",
+		Name: fullName(opts.Namespace, opts.Subsystem, opts.Name),
+		Help: opts.Help,
+	})
+	return d.factory.NewHistogram(opts)
+}
+
+func (d *documentor) NewHistogramVec(opts prometheus.HistogramOpts, labelNames []string) *prometheus.HistogramVec {
+	d.metrics = append(d.metrics, DocumentedMetric{
+		Type:   "histogram",
+		Name:   fullName(opts.Namespace, opts.Subsystem, opts.Name),
+		Help:   opts.Help,
+		Labels: labelNames,
+	})
+	return d.factory.NewHistogramVec(opts, labelNames)
+}
+
+func (d *documentor) NewSummary(opts prometheus.SummaryOpts) prometheus.Summary {
+	d.metrics = append(d.metrics, DocumentedMetric{
+		Type: "summary",
+		Name: fullName(opts.Namespace, opts.Subsystem, opts.Name),
+		Help: opts.Help,
+	})
+	return d.factory.NewSummary(opts)
+}
+
+func (d *documentor) NewSummaryVec(opts prometheus.SummaryOpts, labelNames []string) *prometheus.SummaryVec {
+	d.metrics = append(d.metrics, DocumentedMetric{
+		Type:   "summary",
+		Name:   fullName(opts.Namespace, opts.Subsystem, opts.Name),
+		Help:   opts.Help,
+		Labels: labelNames,
+	})
+	return d.factory.NewSummaryVec(opts, labelNames)
+}
+
+func (d *documentor) Document() []DocumentedMetric {
+	return d.metrics
+}
+
+func fullName(ns, subsystem, name string) string {
+	out := ns
+	if subsystem != "" {
+		out += "_" + subsystem
+	}
+	return out + "_" + name
+}