fix the proxy server backend metric error

go.sum

@@ -532,4 +532,4 @@ sigs.k8s.io/structured-merge-diff/v4 v4.1.2 h1:Hr/htKFmJEbtMgS/UD0N+gtgctAqz81t3
 sigs.k8s.io/structured-merge-diff/v4 v4.1.2/go.mod h1:j/nl6xW8vLS49O8YvXW1ocPhZawJtm+Yrr7PPRQ0Vg4=
 sigs.k8s.io/yaml v1.1.0/go.mod h1:UJmg0vDUVViEyp3mgSv9WPwZCDxu4rQW1olrI1uml+o=
 sigs.k8s.io/yaml v1.2.0 h1:kr/MCeFWJWTwyaHoR9c8EjH9OumOmoF9YGiZd7lFm/Q=
-sigs.k8s.io/yaml v1.2.0/go.mod h1:yfXDCHCao9+ENCvLSE62v9VSji2MKu5jeNfTrofGhJc=
+sigs.k8s.io/yaml v1.2.0/go.mod h1:yfXDCHCao9+ENCvLSE62v9VSji2MKu5jeNfTrofGhJc=

pkg/server/backend_manager.go

@@ -25,7 +25,7 @@ import (
 	"time"
 
 	"k8s.io/klog/v2"
-	client "sigs.k8s.io/apiserver-network-proxy/konnectivity-client/proto/client"
+	"sigs.k8s.io/apiserver-network-proxy/konnectivity-client/proto/client"
 	pkgagent "sigs.k8s.io/apiserver-network-proxy/pkg/agent"
 	"sigs.k8s.io/apiserver-network-proxy/pkg/server/metrics"
 	"sigs.k8s.io/apiserver-network-proxy/proto/agent"
@@ -155,21 +155,25 @@ type DefaultBackendStorage struct {
 	// e.g., when associating to the DestHostBackendManager, it can only use the
 	// identifiers of types, IPv4, IPv6 and Host.
 	idTypes []pkgagent.IdentifierType
+	// managerName defines this storage belongs to what kind of backend manager.
+	// It is used to record some metrics.
+	managerName string
 }
 
 // NewDefaultBackendManager returns a DefaultBackendManager.
 func NewDefaultBackendManager() *DefaultBackendManager {
 	return &DefaultBackendManager{
 		DefaultBackendStorage: NewDefaultBackendStorage(
-			[]pkgagent.IdentifierType{pkgagent.UID})}
+			[]pkgagent.IdentifierType{pkgagent.UID}, "DefaultBackendManager")}
 }
 
 // NewDefaultBackendStorage returns a DefaultBackendStorage
-func NewDefaultBackendStorage(idTypes []pkgagent.IdentifierType) *DefaultBackendStorage {
+func NewDefaultBackendStorage(idTypes []pkgagent.IdentifierType, managerName string) *DefaultBackendStorage {
 	return &DefaultBackendStorage{
-		backends: make(map[string][]*backend),
-		random:   rand.New(rand.NewSource(time.Now().UnixNano())),
-		idTypes:  idTypes,
+		backends:    make(map[string][]*backend),
+		random:      rand.New(rand.NewSource(time.Now().UnixNano())),
+		idTypes:     idTypes,
+		managerName: managerName,
 	} /* #nosec G404 */
 }
 
@@ -204,7 +208,7 @@ func (s *DefaultBackendStorage) AddBackend(identifier string, idType pkgagent.Id
 		return addedBackend
 	}
 	s.backends[identifier] = []*backend{addedBackend}
-	metrics.Metrics.SetBackendCount(len(s.backends))
+	metrics.Metrics.SetBackendCount(s.managerName, string(idType), len(s.backends[string(idType)]))
 	s.agentIDs = append(s.agentIDs, identifier)
 	if idType == pkgagent.DefaultRoute {
 		s.defaultRouteAgentIDs = append(s.defaultRouteAgentIDs, identifier)
@@ -257,7 +261,7 @@ func (s *DefaultBackendStorage) RemoveBackend(identifier string, idType pkgagent
 	if !found {
 		klog.V(1).InfoS("Could not find connection matching identifier to remove", "connection", conn, "identifier", identifier)
 	}
-	metrics.Metrics.SetBackendCount(len(s.backends))
+	metrics.Metrics.SetBackendCount(s.managerName, string(idType), len(s.backends[string(idType)]))
 }
 
 // NumBackends resturns the number of available backends

pkg/server/default_route_backend_manager.go

@@ -20,7 +20,7 @@ import (
 	"context"
 
 	"k8s.io/klog/v2"
-	"sigs.k8s.io/apiserver-network-proxy/pkg/agent"
+	pkgagent "sigs.k8s.io/apiserver-network-proxy/pkg/agent"
 )
 
 type DefaultRouteBackendManager struct {
@@ -32,20 +32,21 @@ var _ BackendManager = &DefaultRouteBackendManager{}
 func NewDefaultRouteBackendManager() *DefaultRouteBackendManager {
 	return &DefaultRouteBackendManager{
 		DefaultBackendStorage: NewDefaultBackendStorage(
-			[]agent.IdentifierType{agent.DefaultRoute})}
+			[]pkgagent.IdentifierType{pkgagent.DefaultRoute},
+			"DefaultRouteBackendManager")}
 }
 
 // Backend tries to get a backend associating to the request destination host.
-func (dibm *DefaultRouteBackendManager) Backend(ctx context.Context) (Backend, error) {
-	dibm.mu.RLock()
-	defer dibm.mu.RUnlock()
-	if len(dibm.backends) == 0 {
+func (drbm *DefaultRouteBackendManager) Backend(ctx context.Context) (Backend, error) {
+	drbm.mu.RLock()
+	defer drbm.mu.RUnlock()
+	if len(drbm.backends) == 0 {
 		return nil, &ErrNotFound{}
 	}
-	if len(dibm.defaultRouteAgentIDs) == 0 {
+	if len(drbm.defaultRouteAgentIDs) == 0 {
 		return nil, &ErrNotFound{}
 	}
-	agentID := dibm.defaultRouteAgentIDs[dibm.random.Intn(len(dibm.defaultRouteAgentIDs))]
+	agentID := drbm.defaultRouteAgentIDs[drbm.random.Intn(len(drbm.defaultRouteAgentIDs))]
 	klog.V(4).InfoS("Picked agent as backend", "agentID", agentID)
-	return dibm.backends[agentID][0], nil
+	return drbm.backends[agentID][0], nil
 }

pkg/server/desthost_backend_manager.go

@@ -20,7 +20,7 @@ import (
 	"context"
 
 	"k8s.io/klog/v2"
-	"sigs.k8s.io/apiserver-network-proxy/pkg/agent"
+	pkgagent "sigs.k8s.io/apiserver-network-proxy/pkg/agent"
 )
 
 type DestHostBackendManager struct {
@@ -32,22 +32,23 @@ var _ BackendManager = &DestHostBackendManager{}
 func NewDestHostBackendManager() *DestHostBackendManager {
 	return &DestHostBackendManager{
 		DefaultBackendStorage: NewDefaultBackendStorage(
-			[]agent.IdentifierType{agent.IPv4, agent.IPv6, agent.Host})}
+			[]pkgagent.IdentifierType{pkgagent.IPv4, pkgagent.IPv6, pkgagent.Host},
+			"DestHostBackendManager")}
 }
 
 // Backend tries to get a backend associating to the request destination host.
-func (dibm *DestHostBackendManager) Backend(ctx context.Context) (Backend, error) {
-	dibm.mu.RLock()
-	defer dibm.mu.RUnlock()
-	if len(dibm.backends) == 0 {
+func (dhbm *DestHostBackendManager) Backend(ctx context.Context) (Backend, error) {
+	dhbm.mu.RLock()
+	defer dhbm.mu.RUnlock()
+	if len(dhbm.backends) == 0 {
 		return nil, &ErrNotFound{}
 	}
 	destHost := ctx.Value(destHost).(string)
 	if destHost != "" {
-		bes, exist := dibm.backends[destHost]
+		bes, exist := dhbm.backends[destHost]
 		if exist && len(bes) > 0 {
 			klog.V(5).InfoS("Get the backend through the DestHostBackendManager", "destHost", destHost)
-			return dibm.backends[destHost][0], nil
+			return dhbm.backends[destHost][0], nil
 		}
 	}
 	return nil, &ErrNotFound{}

pkg/server/metrics/metrics.go

@@ -99,7 +99,10 @@ func newServerMetrics() *ServerMetrics {
 			Name:      "ready_backend_connections",
 			Help:      "Number of konnectivity agent connected to the proxy server",
 		},
-		[]string{},
+		[]string{
+			"manager",
+			"idType",
+		},
 	)
 	pendingDials := prometheus.NewGaugeVec(
 		prometheus.GaugeOpts{
@@ -160,8 +163,8 @@ func (a *ServerMetrics) HTTPConnectionInc() { a.httpConnections.Inc() }
 func (a *ServerMetrics) HTTPConnectionDec() { a.httpConnections.Dec() }
 
 // SetBackendCount sets the number of backend connection.
-func (a *ServerMetrics) SetBackendCount(count int) {
-	a.backend.WithLabelValues().Set(float64(count))
+func (a *ServerMetrics) SetBackendCount(managerName string, idType string, count int) {
+	a.backend.WithLabelValues(managerName, idType).Set(float64(count))
 }
 
 // SetPendingDialCount sets the number of pending dials.