metric-api: Add prometheus metrics

Dockerfile

@@ -13,7 +13,7 @@ RUN set -ex \
     && export COMMIT=$(git rev-parse --short HEAD) \
     && export VERSION=$(go run ./cmd/internal/read_tag) \
     && go build -v -trimpath -tags \
-        "with_gvisor,with_quic,with_dhcp,with_wireguard,with_ech,with_utls,with_reality_server,with_acme,with_clash_api" \
+        "with_gvisor,with_quic,with_dhcp,with_wireguard,with_ech,with_utls,with_reality_server,with_acme,with_clash_api,with_metric_api" \
         -o /go/bin/sing-box \
         -ldflags "-X \"github.com/sagernet/sing-box/constant.Version=$VERSION\" -s -w -buildid= -checklinkname=0" \
         ./cmd/sing-box

Makefile

@@ -1,6 +1,6 @@
 NAME = sing-box
 COMMIT = $(shell git rev-parse --short HEAD)
-TAGS_GO120 = with_gvisor,with_dhcp,with_wireguard,with_reality_server,with_clash_api,with_quic,with_utls
+TAGS_GO120 = with_gvisor,with_dhcp,with_wireguard,with_reality_server,with_clash_api,with_metric_api,with_quic,with_utls
 TAGS_GO121 = with_ech
 TAGS ?= $(TAGS_GO118),$(TAGS_GO120),$(TAGS_GO121)
 TAGS_TEST ?= with_gvisor,with_quic,with_wireguard,with_grpc,with_ech,with_utls,with_reality_server

adapter/experimental.go

@@ -118,10 +118,20 @@ func OutboundTag(detour Outbound) string {
 
 type V2RayServer interface {
 	Service
-	StatsService() V2RayStatsService
+	StatsService() PacketTracking
 }
 
-type V2RayStatsService interface {
-	RoutedConnection(inbound string, outbound string, user string, conn net.Conn) net.Conn
-	RoutedPacketConnection(inbound string, outbound string, user string, conn N.PacketConn) N.PacketConn
+type MetricService interface {
+	Service
+	PacketTracking
 }
+
+type PacketTracking interface {
+	WithConnCounters(inbound, outbound, user string) ConnAdapter[net.Conn]
+	WithPacketConnCounters(inbound, outbound, user string) ConnAdapter[N.PacketConn]
+}
+
+// ConnAdapter
+// Transform a connection to another connection. The T should be either of
+// net.Conn or N.PacketConn.
+type ConnAdapter[T any] func(T) T

box.go

@@ -61,6 +61,7 @@ func New(options Options) (*Box, error) {
 	var needCacheFile bool
 	var needClashAPI bool
 	var needV2RayAPI bool
+	var needMetricAPI bool
 	if experimentalOptions.CacheFile != nil && experimentalOptions.CacheFile.Enabled || options.PlatformLogWriter != nil {
 		needCacheFile = true
 	}
@@ -70,6 +71,9 @@ func New(options Options) (*Box, error) {
 	if experimentalOptions.V2RayAPI != nil && experimentalOptions.V2RayAPI.Listen != "" {
 		needV2RayAPI = true
 	}
+	if experimentalOptions.MetricAPI.Enabled() {
+		needMetricAPI = true
+	}
 	var defaultLogWriter io.Writer
 	if options.PlatformInterface != nil {
 		defaultLogWriter = io.Discard
@@ -183,6 +187,14 @@ func New(options Options) (*Box, error) {
 		router.SetV2RayServer(v2rayServer)
 		preServices2["v2ray api"] = v2rayServer
 	}
+	if needMetricAPI {
+		metricServer, err := experimental.NewMetricServer(logFactory.NewLogger("metric-api"), common.PtrValueOrDefault(experimentalOptions.MetricAPI))
+		if err != nil {
+			return nil, E.Cause(err, "create metric api server")
+		}
+		router.SetMetricServer(metricServer)
+		preServices2["metric api"] = metricServer
+	}
 	return &Box{
 		router:       router,
 		inbounds:     inbounds,

cmd/internal/build_libbox/main.go

@@ -54,7 +54,7 @@ func init() {
 	sharedFlags = append(sharedFlags, "-ldflags", "-X github.com/sagernet/sing-box/constant.Version="+currentTag+" -s -w -buildid=")
 	debugFlags = append(debugFlags, "-ldflags", "-X github.com/sagernet/sing-box/constant.Version="+currentTag)
 
-	sharedTags = append(sharedTags, "with_gvisor", "with_quic", "with_wireguard", "with_ech", "with_utls", "with_clash_api")
+	sharedTags = append(sharedTags, "with_gvisor", "with_quic", "with_wireguard", "with_ech", "with_utls", "with_clash_api", "with_metric_api")
 	iosTags = append(iosTags, "with_dhcp", "with_low_memory", "with_conntrack")
 	debugTags = append(debugTags, "debug")
 }

docs/configuration/experimental/metric-api.md

@@ -0,0 +1,19 @@
+
+### Structure
+
+```json
+{
+  "listen": ":8080",
+  "path": "/metrics"
+}
+```
+
+### Fields
+
+#### listen
+
+Prometheus metrics API listening address, disabled if empty.
+
+#### path
+
+Prometheus scrape path, `/metrics` will be used if empty.

docs/configuration/experimental/metric-api.zh.md

@@ -0,0 +1,19 @@
+
+### Structure
+
+```json
+{
+  "listen": ":8080",
+  "path": "/metrics"
+}
+```
+
+### Fields
+
+#### listen
+
+Prometheus 指标监听地址，如果为空则禁用。
+
+#### path
+
+HTTP 路径，如果为空则使用 `/metrics`。本路径可用于 Prometheus exporter 进行抓取。

docs/installation/build-from-source.md

@@ -65,6 +65,7 @@ go build -tags "tag_a tag_b" ./cmd/sing-box
 | `with_reality_server`              | :material-check:   | Build with reality TLS server support,  see [TLS](/configuration/shared/tls/).                                                                                                                                                                                                                                                 |
 | `with_acme`                        | :material-check:   | Build with ACME TLS certificate issuer support, see [TLS](/configuration/shared/tls/).                                                                                                                                                                                                                                         |
 | `with_clash_api`                   | :material-check:   | Build with Clash API support, see [Experimental](/configuration/experimental#clash-api-fields).                                                                                                                                                                                                                                |
+| `with_metric_api`                  | :material-check:   | Build with Prometheus metric API support, see [Experimental](/configuration/experimental#metric-api-fields).                                                                                                                                                                                                                                |
 | `with_v2ray_api`                   | :material-close:️  | Build with V2Ray API support, see [Experimental](/configuration/experimental#v2ray-api-fields).                                                                                                                                                                                                                                |
 | `with_gvisor`                      | :material-check:   | Build with gVisor support, see [Tun inbound](/configuration/inbound/tun#stack) and [WireGuard outbound](/configuration/outbound/wireguard#system_interface).                                                                                                                                                                   |
 | `with_embedded_tor` (CGO required) | :material-close:️  | Build with embedded Tor support, see [Tor outbound](/configuration/outbound/tor/).                                                                                                                                                                                                                                             |

docs/installation/build-from-source.zh.md

@@ -65,6 +65,7 @@ go build -tags "tag_a tag_b" ./cmd/sing-box
 | `with_reality_server`              | :material-check:  | Build with reality TLS server support,  see [TLS](/configuration/shared/tls/).                                                                                                                                                                                                                                                 |
 | `with_acme`                        | :material-check:  | Build with ACME TLS certificate issuer support, see [TLS](/configuration/shared/tls/).                                                                                                                                                                                                                                         |
 | `with_clash_api`                   | :material-check:  | Build with Clash API support, see [Experimental](/configuration/experimental#clash-api-fields).                                                                                                                                                                                                                                |
+| `with_metric_api`                  | :material-check:  | Build with Prometheus metric API support, see [Experimental](/configuration/experimental#metric-api-fields).                                                                                                                                                                                                                                |
 | `with_v2ray_api`                   | :material-close:️ | Build with V2Ray API support, see [Experimental](/configuration/experimental#v2ray-api-fields).                                                                                                                                                                                                                                |
 | `with_gvisor`                      | :material-check:  | Build with gVisor support, see [Tun inbound](/configuration/inbound/tun#stack) and [WireGuard outbound](/configuration/outbound/wireguard#system_interface).                                                                                                                                                                   |
 | `with_embedded_tor` (CGO required) | :material-close:️ | Build with embedded Tor support, see [Tor outbound](/configuration/outbound/tor/).                                                                                                                                                                                                                                             |

experimental/metricapi.go

@@ -0,0 +1,24 @@
+package experimental
+
+import (
+	"os"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/option"
+)
+
+type MetricServerConstructor = func(logger log.Logger, options option.MetricOptions) (adapter.MetricService, error)
+
+var metricServerConstructor MetricServerConstructor
+
+func RegisterMetricServerConstructor(constructor MetricServerConstructor) {
+	metricServerConstructor = constructor
+}
+
+func NewMetricServer(logger log.Logger, options option.MetricOptions) (adapter.MetricService, error) {
+	if metricServerConstructor == nil {
+		return nil, os.ErrInvalid
+	}
+	return metricServerConstructor(logger, options)
+}

experimental/metrics/server.go

@@ -0,0 +1,72 @@
+package metrics
+
+import (
+	"net/http"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/experimental"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/option"
+	"github.com/sagernet/sing/common"
+
+	"github.com/go-chi/chi/v5"
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+)
+
+var _ adapter.MetricService = (*metricServer)(nil)
+
+func init() {
+	experimental.RegisterMetricServerConstructor(NewServer)
+}
+
+type metricServer struct {
+	http *http.Server
+
+	logger log.Logger
+	opts   option.MetricOptions
+
+	packetCountersInbound  *prometheus.CounterVec
+	packetCountersOutbound *prometheus.CounterVec
+}
+
+func NewServer(logger log.Logger, opts option.MetricOptions) (adapter.MetricService, error) {
+	r := chi.NewRouter()
+	_server := &http.Server{
+		Addr:    opts.Listen,
+		Handler: r,
+	}
+	if opts.Path == "" {
+		opts.Path = "/metrics"
+	}
+	r.Get(opts.Path, promhttp.Handler().ServeHTTP)
+	server := &metricServer{
+		http:   _server,
+		logger: logger,
+		opts:   opts,
+	}
+	err := server.registerMetrics()
+	return server, err
+}
+
+func (s *metricServer) Start() error {
+	if !s.opts.Enabled() {
+		return nil
+	}
+	go func() {
+		err := s.http.ListenAndServe()
+		if err != nil {
+			s.logger.Error("metrics api listen error", err)
+		} else {
+			s.logger.Info("metrics api listening at ", s.http.Addr, s.opts.Path)
+		}
+	}()
+	return nil
+}
+
+func (s *metricServer) Close() error {
+	if !s.opts.Enabled() {
+		return nil
+	}
+	return common.Close(common.PtrOrNil(s.http))
+}

experimental/metrics/tracker.go

@@ -0,0 +1,52 @@
+package metrics
+
+import (
+	"net"
+
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing/common/bufio"
+	N "github.com/sagernet/sing/common/network"
+
+	"github.com/prometheus/client_golang/prometheus"
+)
+
+func (s *metricServer) registerMetrics() error {
+	s.packetCountersInbound = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Name: "inbound_packet_bytes",
+		Help: "Total bytes of inbound packets",
+	}, []string{"inbound", "user"})
+
+	s.packetCountersOutbound = prometheus.NewCounterVec(prometheus.CounterOpts{
+		Name: "outbound_packet_bytes",
+		Help: "Total bytes of outbound packets",
+	}, []string{"outbound", "user"})
+	var err error
+	err = prometheus.Register(s.packetCountersInbound)
+	err = prometheus.Register(s.packetCountersOutbound)
+	return err
+}
+
+func (s *metricServer) WithConnCounters(inbound, outbound, user string) adapter.ConnAdapter[net.Conn] {
+	incRead, incWrite := s.getPacketCounters(inbound, outbound, user)
+	return func(conn net.Conn) net.Conn {
+		return bufio.NewCounterConn(conn, []N.CountFunc{incRead}, []N.CountFunc{incWrite})
+	}
+}
+
+func (s *metricServer) WithPacketConnCounters(inbound, outbound, user string) adapter.ConnAdapter[N.PacketConn] {
+	incRead, incWrite := s.getPacketCounters(inbound, outbound, user)
+	return func(conn N.PacketConn) N.PacketConn {
+		return bufio.NewCounterPacketConn(conn, []N.CountFunc{incRead}, []N.CountFunc{incWrite})
+	}
+}
+
+func (s *metricServer) getPacketCounters(inbound, outbound, user string) (
+	readCounters N.CountFunc,
+	writeCounters N.CountFunc,
+) {
+	return func(n int64) {
+			s.packetCountersInbound.WithLabelValues(inbound, user).Add(float64(n))
+		}, func(n int64) {
+			s.packetCountersOutbound.WithLabelValues(outbound, user).Add(float64(n))
+		}
+}

experimental/v2rayapi/server.go

@@ -70,6 +70,6 @@ func (s *Server) Close() error {
 	)
 }
 
-func (s *Server) StatsService() adapter.V2RayStatsService {
+func (s *Server) StatsService() adapter.PacketTracking {
 	return s.statsService
 }

experimental/v2rayapi/stats.go

@@ -22,7 +22,7 @@ func init() {
 }
 
 var (
-	_ adapter.V2RayStatsService = (*StatsService)(nil)
+	_ adapter.PacketTracking = (*StatsService)(nil)
 	_ StatsServiceServer     = (*StatsService)(nil)
 )
 
@@ -60,14 +60,14 @@ func NewStatsService(options option.V2RayStatsServiceOptions) *StatsService {
 	}
 }
 
-func (s *StatsService) RoutedConnection(inbound string, outbound string, user string, conn net.Conn) net.Conn {
+func (s *StatsService) getPacketCounters(inbound, outbound, user string) (incRead N.CountFunc, inWrite N.CountFunc) {
 	var readCounter []*atomic.Int64
 	var writeCounter []*atomic.Int64
 	countInbound := inbound != "" && s.inbounds[inbound]
 	countOutbound := outbound != "" && s.outbounds[outbound]
 	countUser := user != "" && s.users[user]
 	if !countInbound && !countOutbound && !countUser {
-		return conn
+		return func(n int64) {}, func(n int64) {}
 	}
 	s.access.Lock()
 	if countInbound {
@@ -83,33 +83,29 @@ func (s *StatsService) RoutedConnection(inbound string, outbound string, user st
 		writeCounter = append(writeCounter, s.loadOrCreateCounter("user>>>"+user+">>>traffic>>>downlink"))
 	}
 	s.access.Unlock()
-	return bufio.NewInt64CounterConn(conn, readCounter, writeCounter)
+	return func(n int64) {
+			for _, c := range readCounter {
+				c.Add(n)
+			}
+		}, func(n int64) {
+			for _, c := range writeCounter {
+				c.Add(n)
+			}
+		}
 }
 
-func (s *StatsService) RoutedPacketConnection(inbound string, outbound string, user string, conn N.PacketConn) N.PacketConn {
-	var readCounter []*atomic.Int64
-	var writeCounter []*atomic.Int64
-	countInbound := inbound != "" && s.inbounds[inbound]
-	countOutbound := outbound != "" && s.outbounds[outbound]
-	countUser := user != "" && s.users[user]
-	if !countInbound && !countOutbound && !countUser {
-		return conn
+func (s *StatsService) WithConnCounters(inbound, outbound, user string) adapter.ConnAdapter[net.Conn] {
+	rd, wr := s.getPacketCounters(inbound, outbound, user)
+	return func(conn net.Conn) net.Conn {
+		return bufio.NewCounterConn(conn, []N.CountFunc{rd}, []N.CountFunc{wr})
 	}
-	s.access.Lock()
-	if countInbound {
-		readCounter = append(readCounter, s.loadOrCreateCounter("inbound>>>"+inbound+">>>traffic>>>uplink"))
-		writeCounter = append(writeCounter, s.loadOrCreateCounter("inbound>>>"+inbound+">>>traffic>>>downlink"))
 }
-	if countOutbound {
-		readCounter = append(readCounter, s.loadOrCreateCounter("outbound>>>"+outbound+">>>traffic>>>uplink"))
-		writeCounter = append(writeCounter, s.loadOrCreateCounter("outbound>>>"+outbound+">>>traffic>>>downlink"))
+
+func (s *StatsService) WithPacketConnCounters(inbound, outbound, user string) adapter.ConnAdapter[N.PacketConn] {
+	rd, wr := s.getPacketCounters(inbound, outbound, user)
+	return func(conn N.PacketConn) N.PacketConn {
+		return bufio.NewCounterPacketConn(conn, []N.CountFunc{rd}, []N.CountFunc{wr})
 	}
-	if countUser {
-		readCounter = append(readCounter, s.loadOrCreateCounter("user>>>"+user+">>>traffic>>>uplink"))
-		writeCounter = append(writeCounter, s.loadOrCreateCounter("user>>>"+user+">>>traffic>>>downlink"))
-	}
-	s.access.Unlock()
-	return bufio.NewInt64CounterPacketConn(conn, readCounter, writeCounter)
 }
 
 func (s *StatsService) GetStats(ctx context.Context, request *GetStatsRequest) (*GetStatsResponse, error) {

go.mod

@@ -50,7 +50,7 @@ require (
 	golang.org/x/sys v0.22.0
 	golang.zx2c4.com/wireguard/wgctrl v0.0.0-20230429144221-925a1e7659e6
 	google.golang.org/grpc v1.63.2
-	google.golang.org/protobuf v1.33.0
+	google.golang.org/protobuf v1.34.2
 	howett.net/plist v1.0.1
 )
 
@@ -72,7 +72,7 @@ require (
 	github.com/hashicorp/yamux v0.1.1 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/josharian/native v1.1.0 // indirect
-	github.com/klauspost/compress v1.17.4 // indirect
+	github.com/klauspost/compress v1.17.9 // indirect
 	github.com/klauspost/cpuid/v2 v2.2.5 // indirect
 	github.com/libdns/libdns v0.2.2 // indirect
 	github.com/mdlayher/netlink v1.7.2 // indirect
@@ -81,6 +81,7 @@ require (
 	github.com/onsi/ginkgo/v2 v2.9.7 // indirect
 	github.com/pierrec/lz4/v4 v4.1.14 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/prometheus/client_golang v1.20.2 // indirect
 	github.com/quic-go/qpack v0.4.0 // indirect
 	github.com/quic-go/qtls-go1-20 v0.4.1 // indirect
 	github.com/sagernet/netlink v0.0.0-20240612041022-b9a21c07ac6a // indirect

go.sum

@@ -53,6 +53,7 @@ github.com/josharian/native v1.1.0 h1:uuaP0hAbW7Y4l0ZRQ6C9zfb7Mg1mbFKry/xzDAfmtL
 github.com/josharian/native v1.1.0/go.mod h1:7X/raswPFr05uY3HiLlYeyQntB6OO7E/d2Cu7qoaN2w=
 github.com/klauspost/compress v1.17.4 h1:Ej5ixsIri7BrIjBkRZLTo6ghwrEtHFk7ijlczPW4fZ4=
 github.com/klauspost/compress v1.17.4/go.mod h1:/dCuZOvVtNoHsyb+cuJD3itjs3NbnF6KH9zAO4BDxPM=
+github.com/klauspost/compress v1.17.9/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
 github.com/klauspost/cpuid/v2 v2.0.12/go.mod h1:g2LTdtYhdyuGPqyWyv7qRAmj1WBqxuObKfj5c0PQa7c=
 github.com/klauspost/cpuid/v2 v2.2.5 h1:0E5MSMDEoAulmXNFquVs//DdoomxaoTY1kUhbc/qbZg=
 github.com/klauspost/cpuid/v2 v2.2.5/go.mod h1:Lcz8mBdAVJIBVzewtcLocK12l3Y+JytZYpaMropDUws=
@@ -91,6 +92,8 @@ github.com/pierrec/lz4/v4 v4.1.14 h1:+fL8AQEZtz/ijeNnpduH0bROTu0O3NZAlPjQxGn8LwE
 github.com/pierrec/lz4/v4 v4.1.14/go.mod h1:gZWDp/Ze/IJXGXf23ltt2EXimqmTUXEy0GFuRQyBid4=
 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 v1.20.2 h1:5ctymQzZlyOON1666svgwn3s6IKWgfbjsejTMiXIyjg=
+github.com/prometheus/client_golang v1.20.2/go.mod h1:PIEt8X02hGcP8JWbeHyeZ53Y/jReSnHgO035n//V5WE=
 github.com/quic-go/qpack v0.4.0 h1:Cr9BXA1sQS2SmDUWjSofMPNKmvF6IiIfDRmgU0w1ZCo=
 github.com/quic-go/qpack v0.4.0/go.mod h1:UZVnYIfi5GRk+zI9UMaCPsmZ2xKJP7XBUvVyT1Knj9A=
 github.com/quic-go/qtls-go1-20 v0.4.1 h1:D33340mCNDAIKBqXuAvexTNMUByrYmFYVfKfDN5nfFs=
@@ -213,6 +216,7 @@ google.golang.org/grpc v1.63.2 h1:MUeiw1B2maTVZthpU5xvASfTh3LDbxHd6IJ6QQVU+xM=
 google.golang.org/grpc v1.63.2/go.mod h1:WAX/8DgncnokcFUldAxq7GeB5DXHDbMF+lLvDomNkRA=
 google.golang.org/protobuf v1.33.0 h1:uNO2rsAINq/JlFpSdYEKIZ0uKD/R9cpdv0T+yoGwGmI=
 google.golang.org/protobuf v1.33.0/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
+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 v1.0.0-20200227125254-8fa46927fb4f h1:BLraFXnmrev5lT+xlilqcH8XK9/i0At2xKjWk4p6zsU=
 gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=

include/metricapi.go

@@ -0,0 +1,5 @@
+//go:build with_metric_api
+
+package include
+
+import _ "github.com/sagernet/sing-box/experimental/v2rayapi"

include/metricapi_stub.go

@@ -0,0 +1,17 @@
+//go:build !with_metric_api
+
+package include
+
+import (
+	"github.com/sagernet/sing-box/adapter"
+	"github.com/sagernet/sing-box/experimental"
+	"github.com/sagernet/sing-box/log"
+	"github.com/sagernet/sing-box/option"
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+func init() {
+	experimental.RegisterMetricServerConstructor(func(logger log.Logger, options option.MetricOptions) (adapter.MetricService, error) {
+		return nil, E.New(`metric api is not included in this build, rebuild with -tags with_metric_api`)
+	})
+}

option/experimental.go

@@ -5,6 +5,7 @@ type ExperimentalOptions struct {
 	ClashAPI  *ClashAPIOptions  `json:"clash_api,omitempty"`
 	V2RayAPI  *V2RayAPIOptions  `json:"v2ray_api,omitempty"`
 	Debug     *DebugOptions     `json:"debug,omitempty"`
+	MetricAPI *MetricOptions    `json:"metrics,omitempty"`
 }
 
 type CacheFileOptions struct {
@@ -50,3 +51,12 @@ type V2RayStatsServiceOptions struct {
 	Outbounds []string `json:"outbounds,omitempty"`
 	Users     []string `json:"users,omitempty"`
 }
+
+type MetricOptions struct {
+	Listen string `json:"listen,omitempty"`
+	Path   string `json:"path,omitempty"`
+}
+
+func (m *MetricOptions) Enabled() bool {
+	return m != nil && m.Listen != ""
+}

route/router.go

@@ -93,6 +93,7 @@ type Router struct {
 	pauseManager                       pause.Manager
 	clashServer                        adapter.ClashServer
 	v2rayServer                        adapter.V2RayServer
+	metricServer                       adapter.MetricService
 	platformInterface                  platform.Interface
 	needWIFIState                      bool
 	needPackageManager                 bool
@@ -921,9 +922,12 @@ func (r *Router) RouteConnection(ctx context.Context, conn net.Conn, metadata ad
 	}
 	if r.v2rayServer != nil {
 		if statsService := r.v2rayServer.StatsService(); statsService != nil {
-			conn = statsService.RoutedConnection(metadata.Inbound, detour.Tag(), metadata.User, conn)
+			conn = statsService.WithConnCounters(metadata.Inbound, detour.Tag(), metadata.User)(conn)
 		}
 	}
+	if r.metricServer != nil {
+		conn = r.metricServer.WithConnCounters(metadata.Inbound, detour.Tag(), metadata.User)(conn)
+	}
 	return detour.NewConnection(ctx, conn, metadata)
 }
 
@@ -1097,9 +1101,12 @@ func (r *Router) RoutePacketConnection(ctx context.Context, conn N.PacketConn, m
 	}
 	if r.v2rayServer != nil {
 		if statsService := r.v2rayServer.StatsService(); statsService != nil {
-			conn = statsService.RoutedPacketConnection(metadata.Inbound, detour.Tag(), metadata.User, conn)
+			conn = statsService.WithPacketConnCounters(metadata.Inbound, detour.Tag(), metadata.User)(conn)
 		}
 	}
+	if r.metricServer != nil {
+		conn = r.metricServer.WithPacketConnCounters(metadata.Inbound, detour.Tag(), metadata.User)(conn)
+	}
 	if metadata.FakeIP {
 		conn = bufio.NewNATPacketConn(bufio.NewNetPacketConn(conn), metadata.OriginDestination, metadata.Destination)
 	}
@@ -1265,6 +1272,10 @@ func (r *Router) SetV2RayServer(server adapter.V2RayServer) {
 	r.v2rayServer = server
 }
 
+func (r *Router) SetMetricServer(server adapter.MetricService) {
+	r.metricServer = server
+}
+
 func (r *Router) OnPackagesUpdated(packages int, sharedUsers int) {
 	r.logger.Info("updated packages list: ", packages, " packages, ", sharedUsers, " shared users")
 }