Add prometheus boilerplate

cmd/main.go

@@ -2,24 +2,31 @@ package main
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"math/big"
+	"net/http"
 	"os"
 	"os/signal"
+	"time"
 
 	beethoven "github.com/0xPolygon/beethoven"
-	"github.com/0xPolygon/beethoven/config"
-	"github.com/0xPolygon/beethoven/db"
-	"github.com/0xPolygon/beethoven/etherman"
-	"github.com/0xPolygon/beethoven/rpc"
 	"github.com/0xPolygon/cdk-data-availability/dummyinterfaces"
 	dbConf "github.com/0xPolygon/cdk-validium-node/db"
 	"github.com/0xPolygon/cdk-validium-node/ethtxmanager"
 	"github.com/0xPolygon/cdk-validium-node/jsonrpc"
 	"github.com/0xPolygon/cdk-validium-node/log"
 	"github.com/ethereum/go-ethereum/accounts/abi/bind"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/urfave/cli/v2"
+
+	"github.com/0xPolygon/beethoven/config"
+	"github.com/0xPolygon/beethoven/db"
+	"github.com/0xPolygon/beethoven/etherman"
+	"github.com/0xPolygon/beethoven/pkg/network"
+	"github.com/0xPolygon/beethoven/rpc"
 )
 
 const appName = "cdk-beethoven"
@@ -60,6 +67,7 @@ func start(cliCtx *cli.Context) error {
 	if err != nil {
 		panic(err)
 	}
+
 	setupLog(c.Log)
 
 	// Load private key
@@ -74,7 +82,7 @@ func start(cliCtx *cli.Context) error {
 	if err != nil {
 		log.Fatal(err)
 	}
-	if err := db.RunMigrationsUp(pg); err != nil {
+	if err = db.RunMigrationsUp(pg); err != nil {
 		log.Fatal(err)
 	}
 	storage := db.New(pg)
@@ -117,17 +125,73 @@ func start(cliCtx *cli.Context) error {
 			log.Fatal(err)
 		}
 	}()
+
 	// Run EthTxMan
 	go etm.Start()
 
-	waitSignal(nil)
+	// Run prometheus server
+	closePrometheus, err := runPrometheusServer(c)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	// Stop services
+	waitSignal([]context.CancelFunc{
+		etm.Stop,
+		func() {
+			if err := server.Stop(); err != nil {
+				log.Error(err)
+			}
+		},
+		ethTxManagerStorage.Close,
+		closePrometheus,
+	})
+
 	return nil
 }
 
 func setupLog(c log.Config) {
 	log.Init(c)
 }
 
+func runPrometheusServer(c *config.Config) (func(), error) {
+	if c.Telemetry.PrometheusAddr == "" {
+		return nil, nil
+	}
+
+	addr, err := network.ResolveAddr(c.Telemetry.PrometheusAddr, network.AllInterfacesBinding)
+	if err != nil {
+		return nil, err
+	}
+
+	srv := &http.Server{
+		Addr: addr.String(),
+		Handler: promhttp.InstrumentMetricHandler(
+			prometheus.DefaultRegisterer, promhttp.HandlerFor(
+				prometheus.DefaultGatherer,
+				promhttp.HandlerOpts{},
+			),
+		),
+		ReadHeaderTimeout: 60 * time.Second,
+	}
+
+	log.Infof("prometheus server started: %s", addr)
+
+	go func() {
+		if err := srv.ListenAndServe(); err != nil {
+			if !errors.Is(err, http.ErrServerClosed) {
+				log.Errorf("prometheus HTTP server ListenAndServe: %w", err)
+			}
+		}
+	}()
+
+	return func() {
+		if err := srv.Close(); err != nil {
+			log.Errorf("prometheus HTTP server closing failed: %w", err)
+		}
+	}, nil
+}
+
 func waitSignal(cancelFuncs []context.CancelFunc) {
 	signals := make(chan os.Signal, 1)
 	signal.Notify(signals, os.Interrupt)
@@ -139,7 +203,9 @@ func waitSignal(cancelFuncs []context.CancelFunc) {
 
 			exitStatus := 0
 			for _, cancel := range cancelFuncs {
-				cancel()
+				if cancel != nil {
+					cancel()
+				}
 			}
 			os.Exit(exitStatus)
 		}

config/config.go

@@ -31,13 +31,18 @@ type Config struct {
 	DB           db.Config           `mapstructure:"DB"`
 	EthTxManager ethtxmanager.Config `mapstructure:"EthTxManager"`
 	L1           L1Config            `mapstructure:"L1"`
+	Telemetry    Telemetry           `mapstructure:"Telemetry"`
 }
 
 type L1Config struct {
 	ChainID int64
 	NodeURL string
 }
 
+type Telemetry struct {
+	PrometheusAddr string
+}
+
 // Load loads the configuration baseed on the cli context
 func Load(ctx *cli.Context) (*Config, error) {
 	cfg, err := Default()

config/default.go

@@ -46,6 +46,9 @@ PrivateKeys = [
 [L1]
 ChainID = 1337
 NodeURL = "http://l1:8545"
+
+[Telemetry]
+PrometheusAddr = "0.0.0.0:2223"
 `
 
 // Default parses the default configuration values.

docker/data/beethoven/beethoven.toml

@@ -34,4 +34,7 @@ PrivateKeys = [
 
 [L1]
 ChainID = 1337
-NodeURL = "http://l1:8545"
+NodeURL = "http://l1:8545"
+
+[Telemetry]
+PrometheusAddr = "0.0.0.0:2223"

docker/docker-compose.yaml

@@ -141,6 +141,7 @@ services:
         condition: service_healthy
     ports:
       - '8444:8444'
+      - '2223:2223'
     volumes:
       - ./data/beethoven/beethoven.keystore:/pk/beethoven.keystore
       - ./data/beethoven/beethoven.toml:/config/beethoven.toml

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/gobuffalo/packr/v2 v2.8.3
 	github.com/jackc/pgx/v4 v4.18.1
 	github.com/mitchellh/mapstructure v1.5.0
+	github.com/prometheus/client_golang v1.16.0
 	github.com/rubenv/sql-migrate v1.5.2
 	github.com/spf13/viper v1.17.0
 	github.com/stretchr/testify v1.8.4
@@ -82,7 +83,6 @@ require (
 	github.com/pelletier/go-toml/v2 v2.1.0 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
-	github.com/prometheus/client_golang v1.16.0 // indirect
 	github.com/prometheus/client_model v0.4.0 // indirect
 	github.com/prometheus/common v0.44.0 // indirect
 	github.com/prometheus/procfs v0.10.1 // indirect

pkg/network/network.go

@@ -0,0 +1,25 @@
+package network
+
+import (
+	"fmt"
+	"net"
+)
+
+const (
+	AllInterfacesBinding = "0.0.0.0"
+)
+
+// ResolveAddr resolves the passed in TCP address
+// The second param is the default ip to bind to, if no ip address is specified
+func ResolveAddr(address string, defaultIp string) (*net.TCPAddr, error) {
+	addr, err := net.ResolveTCPAddr("tcp", address)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse addr '%s': %w", address, err)
+	}
+
+	if addr.IP == nil {
+		addr.IP = net.ParseIP(defaultIp)
+	}
+
+	return addr, nil
+}