feat: separate geth metrics server

CHANGELOG.md

@@ -33,7 +33,7 @@
 
 - [\#346](https://github.com/cosmos/evm/pull/346) Add eth_createAccessList method and implementation
 - [\#502](https://github.com/cosmos/evm/pull/502) Add block time in derived logs.
-- [\#588](https://github.com/cosmos/evm/pull/588) go-ethereum metrics are now available in Cosmos SDK's telemetry server at host:port/geth/metrics (default localhost:1317/geth/metrics).
+- [\#633](https://github.com/cosmos/evm/pull/633) go-ethereum metrics are now emitted on a separate server. default address: 127.0.0.1:8080.
 
 ### STATE BREAKING
 

go.mod

@@ -38,7 +38,6 @@ require (
 	github.com/onsi/ginkgo/v2 v2.23.4
 	github.com/onsi/gomega v1.38.0
 	github.com/pkg/errors v0.9.1
-	github.com/prometheus/client_golang v1.22.0
 	github.com/rs/cors v1.11.1
 	github.com/spf13/cast v1.9.2
 	github.com/spf13/cobra v1.9.1
@@ -181,7 +180,6 @@ require (
 	github.com/klauspost/cpuid/v2 v2.2.10 // indirect
 	github.com/kr/pretty v0.3.1 // indirect
 	github.com/kr/text v0.2.0 // indirect
-	github.com/kylelemons/godebug v1.1.0 // indirect
 	github.com/lib/pq v1.10.9 // indirect
 	github.com/manifoldco/promptui v0.9.0 // indirect
 	github.com/mattn/go-colorable v0.1.14 // indirect
@@ -207,6 +205,7 @@ require (
 	github.com/pion/transport/v3 v3.0.1 // indirect
 	github.com/planetscale/vtprotobuf v0.6.1-0.20240319094008-0393e58bdf10 // indirect
 	github.com/pmezard/go-difflib v1.0.1-0.20181226105442-5d4384ee4fb2 // indirect
+	github.com/prometheus/client_golang v1.22.0 // indirect
 	github.com/prometheus/client_model v0.6.1 // indirect
 	github.com/prometheus/common v0.63.0 // indirect
 	github.com/prometheus/procfs v0.15.1 // indirect

metrics/geth.go

@@ -0,0 +1,56 @@
+package metrics
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"time"
+
+	gethmetrics "github.com/ethereum/go-ethereum/metrics"
+	gethprom "github.com/ethereum/go-ethereum/metrics/prometheus"
+
+	"cosmossdk.io/log"
+)
+
+// StartGethMetricServer starts the geth metrics server on the specified address.
+func StartGethMetricServer(ctx context.Context, log log.Logger, addr string) error {
+	mux := http.NewServeMux()
+	mux.Handle("/metrics", gethprom.Handler(gethmetrics.DefaultRegistry))
+
+	server := &http.Server{
+		Addr:    addr,
+		Handler: mux,
+	}
+
+	errCh := make(chan error, 1)
+
+	go func() {
+		log.Info("starting geth metrics server...", "address", addr)
+		errCh <- server.ListenAndServe()
+	}()
+
+	// Start a blocking select to wait for an indication to stop the server or that
+	// the server failed to start properly.
+	select {
+	case <-ctx.Done():
+		// The calling process canceled or closed the provided context, so we must
+		// gracefully stop the metrics server.
+		log.Info("stopping geth metrics server...", "address", addr)
+
+		shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+		defer cancel()
+
+		if err := server.Shutdown(shutdownCtx); err != nil {
+			log.Error("geth metrics server shutdown error", "err", err)
+			return err
+		}
+		return nil
+
+	case err := <-errCh:
+		if err != nil && !errors.Is(err, http.ErrServerClosed) {
+			log.Error("failed to start geth metrics server", "err", err)
+			return err
+		}
+		return nil
+	}
+}

server/config/config.go

@@ -3,6 +3,7 @@ package config
 import (
 	"errors"
 	"fmt"
+	"net/netip"
 	"path"
 	"time"
 
@@ -69,6 +70,9 @@ const (
 	// DefaultEVMMinTip is the default minimum priority fee for the mempool
 	DefaultEVMMinTip = 0
 
+	// DefaultGethMetricsAddr is the default port for the geth metrics server.
+	DefaultGethMetricsAddr = `"127.0.0.1:8080"`
+
 	// DefaultGasCap is the default cap on gas that can be used in eth_call/estimateGas
 	DefaultGasCap uint64 = 25_000_000
 
@@ -148,6 +152,8 @@ type EVMConfig struct {
 	EVMChainID uint64 `mapstructure:"evm-chain-id"`
 	// MinTip defines the minimum priority fee for the mempool
 	MinTip uint64 `mapstructure:"min-tip"`
+	// GethMetricsAddr is the address the geth metrics server will bind to. Default 127.0.0.1:8080
+	GethMetricsAddr string `mapstructure:"geth-metrics-addr"`
 }
 
 // JSONRPCConfig defines configuration for the EVM RPC server.
@@ -218,6 +224,7 @@ func DefaultEVMConfig() *EVMConfig {
 		EVMChainID:              DefaultEVMChainID,
 		EnablePreimageRecording: DefaultEnablePreimageRecording,
 		MinTip:                  DefaultEVMMinTip,
+		GethMetricsAddr:         DefaultGethMetricsAddr,
 	}
 }
 
@@ -227,6 +234,10 @@ func (c EVMConfig) Validate() error {
 		return fmt.Errorf("invalid tracer type %s, available types: %v", c.Tracer, evmTracers)
 	}
 
+	if _, err := netip.ParseAddrPort(c.GethMetricsAddr); err != nil {
+		return fmt.Errorf("invalid geth metrics address %q: %w", c.GethMetricsAddr, err)
+	}
+
 	return nil
 }
 

server/config/toml.go

@@ -25,6 +25,9 @@ evm-chain-id = {{ .EVM.EVMChainID }}
 # MinTip defines the minimum priority fee for the mempool.
 min-tip = {{ .EVM.MinTip }}
 
+# GethMetricsAddr defines the addr to bind the geth metrics server to. Default 127.0.0.1:8080.
+geth-metrics-addr = {{ .EVM.GethMetricsAddr }}
+
 ###############################################################################
 ###                           JSON RPC Configuration                        ###
 ###############################################################################

server/flags/flags.go

@@ -71,6 +71,7 @@ const (
 	EVMEnablePreimageRecording = "evm.cache-preimage"
 	EVMChainID                 = "evm.evm-chain-id"
 	EVMMinTip                  = "evm.min-tip"
+	EvmGethMetricsAddr         = "evm.geth-metrics-addr"
 )
 
 // TLS flags

server/start.go

@@ -9,9 +9,8 @@
 	"path/filepath"
 	"runtime/pprof"
 
-	gethmetrics "github.com/ethereum/go-ethereum/metrics"
+	evmmetrics "github.com/cosmos/evm/metrics"
 	ethmetricsexp "github.com/ethereum/go-ethereum/metrics/exp"
-	gethprom "github.com/ethereum/go-ethereum/metrics/prometheus"
 	"github.com/spf13/cobra"
 	"golang.org/x/sync/errgroup"
 	"google.golang.org/grpc"
@@ -222,6 +221,7 @@
 	cmd.Flags().Bool(srvflags.EVMEnablePreimageRecording, cosmosevmserverconfig.DefaultEnablePreimageRecording, "Enables tracking of SHA3 preimages in the EVM (not implemented yet)")                      //nolint:lll
 	cmd.Flags().Uint64(srvflags.EVMChainID, cosmosevmserverconfig.DefaultEVMChainID, "the EIP-155 compatible replay protection chain ID")
 	cmd.Flags().Uint64(srvflags.EVMMinTip, cosmosevmserverconfig.DefaultEVMMinTip, "the minimum priority fee for the mempool")
+	cmd.Flags().String(srvflags.EvmGethMetricsAddr, cosmosevmserverconfig.DefaultGethMetricsAddr, "the address to bind the geth metrics server to")
 
 	cmd.Flags().String(srvflags.TLSCertPath, "", "the cert.pem file path for the server TLS configuration")
 	cmd.Flags().String(srvflags.TLSKeyPath, "", "the key.pem file path for the server TLS configuration")
@@ -504,7 +504,7 @@
 		defer grpcSrv.GracefulStop()
 	}
 
-	startAPIServer(ctx, svrCtx, clientCtx, g, config.Config, app, grpcSrv, metrics)
+	startAPIServer(ctx, svrCtx, clientCtx, g, config.Config, app, grpcSrv, metrics, config.EVM.GethMetricsAddr)
 
 	if config.JSONRPC.Enable {
 		txApp, ok := app.(AppWithPendingTxStream)
@@ -675,6 +675,7 @@
 	app types.Application,
 	grpcSrv *grpc.Server,
 	metrics *telemetry.Metrics,
+	gethMetricsAddr string,
 ) {
 	if !svrCfg.API.Enable {
 		return
@@ -685,7 +686,9 @@
 
 	if svrCfg.Telemetry.Enabled {
 		apiSrv.SetTelemetry(metrics)
-		apiSrv.Router.Handle("/geth/metrics", gethprom.Handler(gethmetrics.DefaultRegistry))
+		g.Go(func() error {
+			return evmmetrics.StartGethMetricServer(ctx, svrCtx.Logger.With("server", "geth_metrics"), gethMetricsAddr)
+		})
 	}
 
 	g.Go(func() error {