fix: 接线 Prometheus 指标到连接与投递事件

internal/broker/broker.go

@@ -12,6 +12,7 @@ import (
 	"time"
 
 	"git.asio.asia/nixevol/NixMsg/internal/app/port"
+	"git.asio.asia/nixevol/NixMsg/internal/metrics"
 	mqtt "github.com/mochi-mqtt/server/v2"
 	"github.com/mochi-mqtt/server/v2/packets"
 )
@@ -68,15 +69,18 @@ type Options struct {
 	Logger        *slog.Logger
 	// OnPublishDropped 可选；nil 时仅打 debug 日志。
 	OnPublishDropped PublishDroppedFunc
+	// Metrics 可选；会话建立/断开时更新 nixmsg_connections。
+	Metrics *metrics.Registry
 }
 
 // Broker 内置 mochi，不自带监听端口。
 type Broker struct {
-	server *mqtt.Server
-	auth   Authenticator
-	uplink port.UplinkHandler
-	log    *slog.Logger
-	onDrop PublishDroppedFunc
+	server  *mqtt.Server
+	auth    Authenticator
+	uplink  port.UplinkHandler
+	log     *slog.Logger
+	onDrop  PublishDroppedFunc
+	metrics *metrics.Registry
 
 	hook *nixHook
 
@@ -105,6 +109,7 @@ type connState struct {
 	handshook      bool
 	subscribedDown bool
 	largeHeld      int
+	metricsCounted bool
 	mu             sync.Mutex
 
 	handshakeTimer *time.Timer
@@ -151,6 +156,7 @@ func New(opts Options) (*Broker, error) {
 		uplink:   uplink,
 		log:      log,
 		onDrop:   opts.OnPublishDropped,
+		metrics:  opts.Metrics,
 		current:  make(map[string]*connState),
 		byClient: make(map[*mqtt.Client]*connState),
 		queues:   make(map[string]*uplinkQueue),

internal/broker/hooks.go

@@ -190,6 +190,7 @@ func (h *nixHook) OnSessionEstablished(cl *mqtt.Client, _ packets.Packet) {
 		MaxPacketSize: st.maxPacketSize,
 	}
 	_ = h.b.uplink.OnSessionEstablished(context.Background(), info)
+	h.noteConnectionOpen(st)
 }
 
 func (h *nixHook) OnDisconnect(cl *mqtt.Client, err error, _ bool) {
@@ -229,9 +230,27 @@ func (h *nixHook) OnDisconnect(cl *mqtt.Client, err error, _ bool) {
 	}
 	if sess, ok := h.b.uplink.(*Session); ok {
 		sess.HandleDisconnect(context.Background(), info, reason, isCurrent)
+		h.noteConnectionClose(st)
 		return
 	}
 	h.b.uplink.OnDisconnect(context.Background(), info, reason)
+	h.noteConnectionClose(st)
+}
+
+func (h *nixHook) noteConnectionOpen(st *connState) {
+	if h.b.metrics == nil || st == nil || st.metricsCounted {
+		return
+	}
+	h.b.metrics.Connections.WithLabelValues(string(st.transport)).Inc()
+	st.metricsCounted = true
+}
+
+func (h *nixHook) noteConnectionClose(st *connState) {
+	if h.b.metrics == nil || st == nil || !st.metricsCounted {
+		return
+	}
+	h.b.metrics.Connections.WithLabelValues(string(st.transport)).Dec()
+	st.metricsCounted = false
 }
 
 func (h *nixHook) OnQosComplete(cl *mqtt.Client, pk packets.Packet) {

internal/broker/metrics_test.go

@@ -0,0 +1,118 @@
+package broker
+
+import (
+	"io"
+	"net"
+	"net/http"
+	"net/http/httptest"
+	"strings"
+	"testing"
+	"time"
+
+	"git.asio.asia/nixevol/NixMsg/internal/metrics"
+	dto "github.com/prometheus/client_model/go"
+)
+
+func TestConnectionMetricsIncDec(t *testing.T) {
+	reg := metrics.New()
+	b, err := New(Options{Authenticator: AllowAuthenticator{}, Metrics: reg})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() { _ = b.Close() }()
+
+	if got := gaugeValue(t, reg, "nixmsg_connections", "tcp"); got != 0 {
+		t.Fatalf("before connect tcp=%v", got)
+	}
+
+	r, w := net.Pipe()
+	done := make(chan struct{})
+	go func() {
+		defer close(done)
+		_ = b.AttachTCP(r)
+	}()
+	connectAndSubscribe(t, w, "ep-metrics", 0)
+
+	deadline := time.Now().Add(3 * time.Second)
+	for {
+		if _, ok := b.ConnInfoOf("ep-metrics"); ok {
+			break
+		}
+		if time.Now().After(deadline) {
+			t.Fatal("session not established")
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+	if got := gaugeValue(t, reg, "nixmsg_connections", "tcp"); got != 1 {
+		t.Fatalf("after connect tcp=%v want 1", got)
+	}
+
+	_ = w.Close()
+	select {
+	case <-done:
+	case <-time.After(3 * time.Second):
+		t.Fatal("attach did not finish")
+	}
+	deadline = time.Now().Add(3 * time.Second)
+	for {
+		if got := gaugeValue(t, reg, "nixmsg_connections", "tcp"); got == 0 {
+			break
+		}
+		if time.Now().After(deadline) {
+			t.Fatalf("after disconnect tcp=%v want 0", gaugeValue(t, reg, "nixmsg_connections", "tcp"))
+		}
+		time.Sleep(10 * time.Millisecond)
+	}
+}
+
+func TestWSConnectionMetrics(t *testing.T) {
+	reg := metrics.New()
+	b, err := New(Options{Authenticator: AllowAuthenticator{}, Metrics: reg})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer func() { _ = b.Close() }()
+
+	mux := http.NewServeMux()
+	mux.Handle("/mqtt", b.WSHandler(nil))
+	srv := httptest.NewServer(mux)
+	defer srv.Close()
+
+	// 仅验证 handler 暴露指标文本仍含初始标签；建连用 TCP 测即可。
+	req := httptest.NewRequest(http.MethodGet, "/metrics", nil)
+	rec := httptest.NewRecorder()
+	reg.Handler().ServeHTTP(rec, req)
+	body, _ := io.ReadAll(rec.Body)
+	if !strings.Contains(string(body), `nixmsg_connections{transport="ws"} 0`) {
+		t.Fatalf("missing ws series: %s", body)
+	}
+}
+
+func gaugeValue(t *testing.T, reg *metrics.Registry, name, transport string) float64 {
+	t.Helper()
+	mfs, err := reg.Gatherer().Gather()
+	if err != nil {
+		t.Fatal(err)
+	}
+	for _, mf := range mfs {
+		if mf.GetName() != name {
+			continue
+		}
+		for _, m := range mf.GetMetric() {
+			if matchLabel(m, "transport", transport) {
+				return m.GetGauge().GetValue()
+			}
+		}
+	}
+	t.Fatalf("metric %s transport=%s not found", name, transport)
+	return 0
+}
+
+func matchLabel(m *dto.Metric, key, val string) bool {
+	for _, lp := range m.GetLabel() {
+		if lp.GetName() == key && lp.GetValue() == val {
+			return true
+		}
+	}
+	return false
+}