feat(issue-253): initial metrics implementation

README.md

@@ -250,6 +250,10 @@ Usage of mev-boost:
         add a 'service=...' tag to all log messages
   -loglevel string
         minimum loglevel: trace, debug, info, warn/warning, error, fatal, panic (default "info")
+  -metrics
+        enables a metrics server (default: false)
+  -metrics-addr string
+        listening address for the metrics server (default: "localhost:18551")
   -mainnet
         use Mainnet (default true)
   -min-bid float
@@ -313,6 +317,10 @@ Example for setting a minimum bid value of 0.06 ETH:
     -relay $YOUR_RELAY_CHOICE_C
 ```
 
+### Enabling metrics
+
+Optionally, the `-metrics` flag can be provided to expose a prometheus metrics server. The metrics server address/port can be changed with the `-metrics-addr` (e.g., `-metrics-addr localhost:9009`) flag.
+
 ---
 
 # API

cli/flags.go

@@ -34,6 +34,8 @@ var flags = []cli.Flag{
 	timeoutGetPayloadFlag,
 	timeoutRegValFlag,
 	maxRetriesFlag,
+	metricsFlag,
+	metricsAddrFlag,
 }
 
 var (
@@ -83,6 +85,19 @@ var (
 		Usage:    "disables adding the version to every log entry",
 		Category: LoggingCategory,
 	}
+	metricsFlag = &cli.BoolFlag{
+		Name:     "metrics",
+		Sources:  cli.EnvVars("METRICS_ENABLED"),
+		Usage:    "enables a metrics server",
+		Category: LoggingCategory,
+	}
+	metricsAddrFlag = &cli.StringFlag{
+		Name:     "metrics-addr",
+		Sources:  cli.EnvVars("METRICS_ADDR"),
+		Value:    "localhost:18551",
+		Usage:    "listening address for the metrics server",
+		Category: LoggingCategory,
+	}
 	// Genesis Flags
 	customGenesisForkFlag = &cli.StringFlag{
 		Name:     "genesis-fork-version",

cli/main.go

@@ -68,6 +68,8 @@ func start(_ context.Context, cmd *cli.Command) error {
 		genesisForkVersion, genesisTime      = setupGenesis(cmd)
 		relays, monitors, minBid, relayCheck = setupRelays(cmd)
 		listenAddr                           = cmd.String(addrFlag.Name)
+		metricsEnabled                       = cmd.Bool(metricsFlag.Name)
+		metricsAddr                          = cmd.String(metricsAddrFlag.Name)
 	)
 
 	opts := server.BoostServiceOpts{
@@ -83,6 +85,7 @@ func start(_ context.Context, cmd *cli.Command) error {
 		RequestTimeoutGetPayload: time.Duration(cmd.Int(timeoutGetPayloadFlag.Name)) * time.Millisecond,
 		RequestTimeoutRegVal:     time.Duration(cmd.Int(timeoutRegValFlag.Name)) * time.Millisecond,
 		RequestMaxRetries:        int(cmd.Int(maxRetriesFlag.Name)),
+		MetricsAddr:              metricsAddr,
 	}
 	service, err := server.NewBoostService(opts)
 	if err != nil {
@@ -93,7 +96,16 @@ func start(_ context.Context, cmd *cli.Command) error {
 		log.Error("no relay passed the health-check!")
 	}
 
-	log.Infof("Listening on %v", listenAddr)
+	if metricsEnabled {
+		go func() {
+			log.Infof("metrics server listening on %v", opts.MetricsAddr)
+			if err := service.StartMetricsServer(); err != nil {
+				log.WithError(err).Error("metrics server exited with error")
+			}
+		}()
+	}
+
+	log.Infof("listening on %v", listenAddr)
 	return service.StartHTTPServer()
 }
 
@@ -146,7 +158,7 @@ func setupRelays(cmd *cli.Command) (relayList, relayMonitorList, types.U256Str,
 		log.WithError(err).Fatal("Failed sanitizing min bid")
 	}
 	if relayMinBidWei.BigInt().Sign() > 0 {
-		log.Infof("Min bid set to %v eth (%v wei)", cmd.Float(minBidFlag.Name), relayMinBidWei)
+		log.Infof("min bid set to %v eth (%v wei)", cmd.Float(minBidFlag.Name), relayMinBidWei)
 	}
 	return relays, monitors, *relayMinBidWei, cmd.Bool(relayCheckFlag.Name)
 }

go.mod

@@ -9,14 +9,17 @@ require (
 	github.com/google/uuid v1.6.0
 	github.com/gorilla/mux v1.8.1
 	github.com/holiman/uint256 v1.3.2
+	github.com/prometheus/client_golang v1.16.0
 	github.com/prysmaticlabs/go-bitfield v0.0.0-20240618144021-706c95b2dd15
 	github.com/sirupsen/logrus v1.9.3
 	github.com/stretchr/testify v1.10.0
 	github.com/urfave/cli/v3 v3.0.0-beta1
 )
 
 require (
+	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/bits-and-blooms/bitset v1.13.0 // indirect
+	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/consensys/bavard v0.1.13 // indirect
 	github.com/consensys/gnark-crypto v0.12.1 // indirect
 	github.com/crate-crypto/go-ipa v0.0.0-20240223125850-b1e8a79f509c // indirect
@@ -27,13 +30,19 @@ require (
 	github.com/go-playground/validator/v10 v10.11.1 // indirect
 	github.com/goccy/go-yaml v1.11.3 // indirect
 	github.com/gofrs/flock v0.8.1 // indirect
+	github.com/golang/protobuf v1.5.4 // indirect
 	github.com/mattn/go-colorable v0.1.13 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
 	github.com/mmcloughlin/addchain v0.4.0 // indirect
+	github.com/prometheus/client_model v0.3.0 // indirect
+	github.com/prometheus/common v0.42.0 // indirect
+	github.com/prometheus/procfs v0.10.1 // indirect
 	github.com/rivo/uniseg v0.2.0 // indirect
 	github.com/supranational/blst v0.3.13 // indirect
 	golang.org/x/sync v0.7.0 // indirect
 	golang.org/x/xerrors v0.0.0-20231012003039-104605ab7028 // indirect
+	google.golang.org/protobuf v1.34.2 // indirect
 	rsc.io/tmplfunc v0.0.3 // indirect
 )
 

go.sum

@@ -8,6 +8,8 @@ github.com/attestantio/go-eth2-client v0.22.1-0.20250106164842-07b6ce39bb43 h1:l
 github.com/attestantio/go-eth2-client v0.22.1-0.20250106164842-07b6ce39bb43/go.mod h1:vy5jU/uDZ2+RcVzq5BfnG+bQ3/6uu9DGwCrGsPtjJ1A=
 github.com/benbjohnson/clock v1.3.0 h1:ip6w0uFQkncKQ979AypyG0ER7mqUSBdKLOgAle/AT8A=
 github.com/benbjohnson/clock v1.3.0/go.mod h1:J11/hYXuz8f4ySSvYwY0FKfm+ezbsZBKZxNJlLklBHA=
+github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
+github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
 github.com/bits-and-blooms/bitset v1.13.0 h1:bAQ9OPNFYbGHV6Nez0tmNI0RiEu7/hxlYJRUA0wFAVE=
 github.com/bits-and-blooms/bitset v1.13.0/go.mod h1:7hO7Gc7Pp1vODcmWvKMRA9BNmbv6a/7QIWpPxHddWR8=
 github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
@@ -56,6 +58,10 @@ github.com/goccy/go-yaml v1.11.3 h1:B3W9IdWbvrUu2OYQGwvU1nZtvMQJPBKgBUuweJjLj6I=
 github.com/goccy/go-yaml v1.11.3/go.mod h1:wKnAMd44+9JAAnGQpWVEgBzGt3YuTaQ4uXoHvE4m7WU=
 github.com/gofrs/flock v0.8.1 h1:+gYjHKf32LDeiEEFhQaotPbLuUXjY5ZqxKgXy7n59aw=
 github.com/gofrs/flock v0.8.1/go.mod h1:F1TvTiK9OcQqauNUHlbJvyl9Qa1QvF/gOUDKA14jxHU=
+github.com/golang/protobuf v1.2.0/go.mod h1:6lQm79b+lXiMfvg/cZm0SGofjICqVBUtrP5yJMmIC1U=
+github.com/golang/protobuf v1.3.5/go.mod h1:6O5/vntMXwX2lRkT1hjjk0nAC1IDOTvTlVgjlRvqsdk=
+github.com/golang/protobuf v1.5.4 h1:i7eJL8qZTpSEXOPTxNKhASYpMn+8e5Q6AdndVa1dWek=
+github.com/golang/protobuf v1.5.4/go.mod h1:lnTiLA8Wa4RWRcIUkrtSVa5nRhsEGBg48fD6rSs7xps=
 github.com/golang/snappy v0.0.5-0.20220116011046-fa5810519dcb h1:PBC98N2aIaM3XXiurYmW7fx4GZkL8feAMVq7nEjURHk=
 github.com/golang/snappy v0.0.5-0.20220116011046-fa5810519dcb/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
 github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
@@ -96,6 +102,8 @@ github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D
 github.com/mattn/go-runewidth v0.0.9/go.mod h1:H031xJmbD/WCDINGzjvQ9THkh0rPKHF+m2gUSrubnMI=
 github.com/mattn/go-runewidth v0.0.13 h1:lTGmDsbAYt5DmK6OnoV7EuIF1wEIFAcxld6ypU4OSgU=
 github.com/mattn/go-runewidth v0.0.13/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
+github.com/matttproud/golang_protobuf_extensions v1.0.4 h1:mmDVorXM7PCGKw94cs5zkfA9PSy5pEvNWRP0ET0TIVo=
+github.com/matttproud/golang_protobuf_extensions v1.0.4/go.mod h1:BSXmuO+STAnVfrANrmjBb36TMTDstsz7MSK+HVaYKv4=
 github.com/minio/sha256-simd v1.0.1 h1:6kaan5IFmwTNynnKKpDHe6FWHohJOHhCPchzK49dzMM=
 github.com/minio/sha256-simd v1.0.1/go.mod h1:Pz6AKMiUdngCLpeTL/RJY1M9rUuPMYujV5xJjtbRSN8=
 github.com/mitchellh/mapstructure v1.5.0 h1:jeMsZIYE/09sWLaz43PL7Gy6RuMjD2eJVyuac5Z2hdY=
@@ -110,6 +118,14 @@ github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
 github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/prometheus/client_golang v1.16.0 h1:yk/hx9hDbrGHovbci4BY+pRMfSuuat626eFsHb7tmT8=
+github.com/prometheus/client_golang v1.16.0/go.mod h1:Zsulrv/L9oM40tJ7T815tM89lFEugiJ9HzIqaAx4LKc=
+github.com/prometheus/client_model v0.3.0 h1:UBgGFHqYdG/TPFD1B1ogZywDqEkwp3fBMvqdiQ7Xew4=
+github.com/prometheus/client_model v0.3.0/go.mod h1:LDGWKZIo7rky3hgvBe+caln+Dr3dPggB5dvjtD7w9+w=
+github.com/prometheus/common v0.42.0 h1:EKsfXEYo4JpWMHH5cg+KOUWeuJSov1Id8zGR8eeI1YM=
+github.com/prometheus/common v0.42.0/go.mod h1:xBwqVerjNdUDjgODMpudtOMwlOwf2SaTr1yjz4b7Zbc=
+github.com/prometheus/procfs v0.10.1 h1:kYK1Va/YMlutzCGazswoHKo//tZVlFpKYh+PymziUAg=
+github.com/prometheus/procfs v0.10.1/go.mod h1:nwNm2aOCAYw8uTR/9bWRREkZFxAUcWzPHWJq+XBB/FM=
 github.com/prysmaticlabs/go-bitfield v0.0.0-20240618144021-706c95b2dd15 h1:lC8kiphgdOBTcbTvo8MwkvpKjO0SlAgjv4xIK5FGJ94=
 github.com/prysmaticlabs/go-bitfield v0.0.0-20240618144021-706c95b2dd15/go.mod h1:8svFBIKKu31YriBG/pNizo9N0Jr9i5PQ+dFkxWg3x5k=
 github.com/rivo/uniseg v0.2.0 h1:S1pD9weZBuJdFmowNwbpi7BJ8TNftyUImj/0WQi72jY=
@@ -151,6 +167,7 @@ golang.org/x/crypto v0.31.0/go.mod h1:kDsLvtWBEx7MV9tJOj9bnXsPbxwJQ6csT/x4KIN4Ss
 golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa h1:FRnLl4eNAQl8hwxVVC17teOw8kdjVDVAiFMtgUdTSRQ=
 golang.org/x/exp v0.0.0-20231110203233-9a3e6036ecaa/go.mod h1:zk2irFbV9DP96SEBUUAy67IdHUaZuSnrz1n472HUCLE=
 golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
+golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
 golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20190916202348-b4ddaad3f8a3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
@@ -175,6 +192,8 @@ golang.org/x/text v0.21.0/go.mod h1:4IBbMaMmOPCJ8SecivzSH54+73PCFmPWxNTLm+vZkEQ=
 golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/xerrors v0.0.0-20231012003039-104605ab7028 h1:+cNy6SZtPcJQH3LJVLOSmiC7MMxXNOb3PU/VUEz+EhU=
 golang.org/x/xerrors v0.0.0-20231012003039-104605ab7028/go.mod h1:NDW/Ps6MPRej6fsCIbMTohpP40sJ/P/vI1MoTEGwX90=
+google.golang.org/protobuf v1.34.2 h1:6xV6lTsCfpGD21XK49h7MhtcApnLqkfYgPcdHftf6hg=
+google.golang.org/protobuf v1.34.2/go.mod h1:qYOHts0dSfpeUzUFpOMr/WGzszTmLH+DiWniOlNbLDw=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=

server/service.go

@@ -27,6 +27,9 @@ import (
 	"github.com/flashbots/mev-boost/server/types"
 	"github.com/google/uuid"
 	"github.com/gorilla/mux"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/collectors"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/sirupsen/logrus"
 )
 
@@ -69,6 +72,8 @@ type BoostServiceOpts struct {
 	RequestTimeoutGetPayload time.Duration
 	RequestTimeoutRegVal     time.Duration
 	RequestMaxRetries        int
+
+	MetricsAddr string
 }
 
 // BoostService - the mev-boost service
@@ -93,6 +98,8 @@ type BoostService struct {
 
 	slotUID     *slotUID
 	slotUIDLock sync.Mutex
+
+	metricsAddr string
 }
 
 // NewBoostService created a new BoostService
@@ -131,6 +138,7 @@ func NewBoostService(opts BoostServiceOpts) (*BoostService, error) {
 			CheckRedirect: httpClientDisallowRedirects,
 		},
 		requestMaxRetries: opts.RequestMaxRetries,
+		metricsAddr:       opts.MetricsAddr,
 	}, nil
 }
 
@@ -194,6 +202,24 @@ func (m *BoostService) StartHTTPServer() error {
 	return err
 }
 
+// StartMetricsServer starts the HTTP server for exporting open-metrics
+func (m *BoostService) StartMetricsServer() error {
+	prometheusRegistry := prometheus.NewRegistry()
+	if err := prometheusRegistry.Register(collectors.NewGoCollector()); err != nil {
+		m.log.WithError(err).Error("failed to register metrics for GoCollector")
+	}
+	if err := prometheusRegistry.Register(collectors.NewProcessCollector(collectors.ProcessCollectorOpts{})); err != nil {
+		m.log.WithError(err).Error("failed to register ProcessCollector")
+	}
+
+	serveMux := http.NewServeMux()
+	serveMux.Handle("/metrics", promhttp.HandlerFor(prometheusRegistry, promhttp.HandlerOpts{
+		ErrorLog:          m.log,
+		EnableOpenMetrics: true,
+	}))
+	return http.ListenAndServe(m.metricsAddr, serveMux)
+}
+
 func (m *BoostService) startBidCacheCleanupTask() {
 	for {
 		time.Sleep(1 * time.Minute)