Use const labels for Discovery Manager metrics.

Signed-off-by: Paulin Todev <paulin.todev@gmail.com>

cmd/prometheus/main.go

@@ -620,30 +620,56 @@ func main() {
 		discoveryManagerNotify  discoveryManager
 	)
 
-	// Register the metrics used by both "scrape" and "notify" discovery managers.
+	// Kubernetes client metrics are used by Kubernetes SD.
-	// The same metrics are used for both discovery managers. Hence the registration
+	// They are registered here in the main function, because SD mechanisms
-	// needs to be done here, outside the NewManager() calls, to avoid duplicate
+	// can only register metrics specific to a SD instance.
-	// metric registrations.
+	// Kubernetes client metrics are the same for the whole process -
-	discoveryMetrics, err := discovery.NewMetrics(prometheus.DefaultRegisterer)
+	// they are not specific to an SD instance.
+	err = discovery.RegisterK8sClientMetricsWithPrometheus(prometheus.DefaultRegisterer)
 	if err != nil {
-		level.Error(logger).Log("msg", "failed to create discovery metrics", "err", err)
+		level.Error(logger).Log("msg", "failed to register Kubernetes client metrics", "err", err)
 		os.Exit(1)
 	}
 	if cfg.enableNewSDManager {
-		discoveryManagerScrape = discovery.NewManager(ctxScrape, log.With(logger, "component", "discovery manager scrape"), prometheus.DefaultRegisterer, discoveryMetrics, discovery.Name("scrape"))
+		{
-		discoveryManagerNotify = discovery.NewManager(ctxNotify, log.With(logger, "component", "discovery manager notify"), prometheus.DefaultRegisterer, discoveryMetrics, discovery.Name("notify"))
+			discMgr := discovery.NewManager(ctxScrape, log.With(logger, "component", "discovery manager scrape"), prometheus.DefaultRegisterer, discovery.Name("scrape"))
-	} else {
+			if discMgr == nil {
-		discoveryManagerScrape = legacymanager.NewManager(ctxScrape, log.With(logger, "component", "discovery manager scrape"), prometheus.DefaultRegisterer, discoveryMetrics, legacymanager.Name("scrape"))
-		discoveryManagerNotify = legacymanager.NewManager(ctxNotify, log.With(logger, "component", "discovery manager notify"), prometheus.DefaultRegisterer, discoveryMetrics, legacymanager.Name("notify"))
-	}
-
-	if discoveryManagerScrape == nil {
 				level.Error(logger).Log("msg", "failed to create a discovery manager scrape")
 				os.Exit(1)
+			} else {
+				discoveryManagerScrape = discMgr
 			}
-	if discoveryManagerNotify == nil {
+		}
+
+		{
+			discMgr := discovery.NewManager(ctxNotify, log.With(logger, "component", "discovery manager notify"), prometheus.DefaultRegisterer, discovery.Name("notify"))
+			if discMgr == nil {
 				level.Error(logger).Log("msg", "failed to create a discovery manager notify")
 				os.Exit(1)
+			} else {
+				discoveryManagerNotify = discMgr
+			}
+		}
+	} else {
+		{
+			discMgr := legacymanager.NewManager(ctxScrape, log.With(logger, "component", "discovery manager scrape"), prometheus.DefaultRegisterer, legacymanager.Name("scrape"))
+			if discMgr == nil {
+				level.Error(logger).Log("msg", "failed to create a discovery manager scrape")
+				os.Exit(1)
+			} else {
+				discoveryManagerScrape = discMgr
+			}
+		}
+
+		{
+			discMgr := legacymanager.NewManager(ctxNotify, log.With(logger, "component", "discovery manager notify"), prometheus.DefaultRegisterer, legacymanager.Name("notify"))
+			if discMgr == nil {
+				level.Error(logger).Log("msg", "failed to create a discovery manager notify")
+				os.Exit(1)
+			} else {
+				discoveryManagerNotify = discMgr
+			}
+		}
 	}
 
 	scrapeManager, err := scrape.NewManager(

discovery/legacymanager/manager.go

@@ -42,7 +42,7 @@ type provider struct {
 }
 
 // NewManager is the Discovery Manager constructor.
-func NewManager(ctx context.Context, logger log.Logger, registerer prometheus.Registerer, metrics *discovery.Metrics, options ...func(*Manager)) *Manager {
+func NewManager(ctx context.Context, logger log.Logger, registerer prometheus.Registerer, options ...func(*Manager)) *Manager {
 	if logger == nil {
 		logger = log.NewNopLogger()
 	}
@@ -55,11 +55,20 @@ func NewManager(ctx context.Context, logger log.Logger, registerer prometheus.Re
 		updatert:       5 * time.Second,
 		triggerSend:    make(chan struct{}, 1),
 		registerer:     registerer,
-		metrics:        metrics,
 	}
 	for _, option := range options {
 		option(mgr)
 	}
+
+	// Register the metrics.
+	// We have to do this after setting all options, so that the name of the Manager is set.
+	if metrics, err := discovery.NewMetrics(registerer, mgr.name); err == nil {
+		mgr.metrics = metrics
+	} else {
+		level.Error(logger).Log("msg", "Failed to create discovery manager metrics", "manager", mgr.name, "err", err)
+		return nil
+	}
+
 	return mgr
 }
 
@@ -133,9 +142,9 @@ func (m *Manager) ApplyConfig(cfg map[string]discovery.Configs) error {
 	failedCount := 0
 	for name, scfg := range cfg {
 		failedCount += m.registerProviders(scfg, name)
-		m.metrics.DiscoveredTargets.WithLabelValues(m.name, name).Set(0)
+		m.metrics.DiscoveredTargets.WithLabelValues(name).Set(0)
 	}
-	m.metrics.FailedConfigs.WithLabelValues(m.name).Set(float64(failedCount))
+	m.metrics.FailedConfigs.Set(float64(failedCount))
 
 	for _, prov := range m.providers {
 		m.startProvider(m.ctx, prov)
@@ -172,7 +181,7 @@ func (m *Manager) updater(ctx context.Context, p *provider, updates chan []*targ
 		case <-ctx.Done():
 			return
 		case tgs, ok := <-updates:
-			m.metrics.ReceivedUpdates.WithLabelValues(m.name).Inc()
+			m.metrics.ReceivedUpdates.Inc()
 			if !ok {
 				level.Debug(m.logger).Log("msg", "Discoverer channel closed", "provider", p.name)
 				return
@@ -201,11 +210,11 @@ func (m *Manager) sender() {
 		case <-ticker.C: // Some discoverers send updates too often so we throttle these with the ticker.
 			select {
 			case <-m.triggerSend:
-				m.metrics.SentUpdates.WithLabelValues(m.name).Inc()
+				m.metrics.SentUpdates.Inc()
 				select {
 				case m.syncCh <- m.allGroups():
 				default:
-					m.metrics.DelayedUpdates.WithLabelValues(m.name).Inc()
+					m.metrics.DelayedUpdates.Inc()
 					level.Debug(m.logger).Log("msg", "Discovery receiver's channel was full so will retry the next cycle")
 					select {
 					case m.triggerSend <- struct{}{}:
@@ -253,7 +262,7 @@ func (m *Manager) allGroups() map[string][]*targetgroup.Group {
 		}
 	}
 	for setName, v := range n {
-		m.metrics.DiscoveredTargets.WithLabelValues(m.name, setName).Set(float64(v))
+		m.metrics.DiscoveredTargets.WithLabelValues(setName).Set(float64(v))
 	}
 	return tSets
 }

discovery/legacymanager/manager_test.go

@@ -36,12 +36,6 @@ func TestMain(m *testing.M) {
 	testutil.TolerantVerifyLeak(m)
 }
 
-func newTestDiscoveryMetrics(t *testing.T) *discovery.Metrics {
-	metrics, err := discovery.NewMetrics(prometheus.NewRegistry())
-	require.NoError(t, err)
-	return metrics
-}
-
 // TestTargetUpdatesOrder checks that the target updates are received in the expected order.
 func TestTargetUpdatesOrder(t *testing.T) {
 	// The order by which the updates are send is determined by the interval passed to the mock discovery adapter
@@ -671,7 +665,8 @@ func TestTargetUpdatesOrder(t *testing.T) {
 			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 			defer cancel()
 
-			discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+			discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+			require.NotNil(t, discoveryManager)
 			discoveryManager.updatert = 100 * time.Millisecond
 
 			var totalUpdatesCount int
@@ -753,7 +748,8 @@ func verifyPresence(t *testing.T, tSets map[poolKey]map[string]*targetgroup.Grou
 func TestTargetSetRecreatesTargetGroupsEveryRun(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -781,7 +777,8 @@ func TestTargetSetRecreatesTargetGroupsEveryRun(t *testing.T) {
 func TestDiscovererConfigs(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -805,7 +802,8 @@ func TestDiscovererConfigs(t *testing.T) {
 func TestTargetSetRecreatesEmptyStaticConfigs(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -844,7 +842,8 @@ func TestTargetSetRecreatesEmptyStaticConfigs(t *testing.T) {
 func TestIdenticalConfigurationsAreCoalesced(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, nil, prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, nil, prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -875,7 +874,8 @@ func TestApplyConfigDoesNotModifyStaticTargets(t *testing.T) {
 	}
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -900,7 +900,8 @@ func (e errorConfig) NewDiscoverer(discovery.DiscovererOptions) (discovery.Disco
 func TestGaugeFailedConfigs(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -1056,7 +1057,8 @@ func TestCoordinationWithReceiver(t *testing.T) {
 			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 			defer cancel()
 
-			mgr := NewManager(ctx, nil, prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+			mgr := NewManager(ctx, nil, prometheus.NewRegistry())
+			require.NotNil(t, mgr)
 			mgr.updatert = updateDelay
 			go mgr.Run()
 

discovery/manager.go

@@ -65,7 +65,7 @@ func (p *Provider) Config() interface{} {
 }
 
 // NewManager is the Discovery Manager constructor.
-func NewManager(ctx context.Context, logger log.Logger, registerer prometheus.Registerer, metrics *Metrics, options ...func(*Manager)) *Manager {
+func NewManager(ctx context.Context, logger log.Logger, registerer prometheus.Registerer, options ...func(*Manager)) *Manager {
 	if logger == nil {
 		logger = log.NewNopLogger()
 	}
@@ -77,11 +77,20 @@ func NewManager(ctx context.Context, logger log.Logger, registerer prometheus.Re
 		updatert:    5 * time.Second,
 		triggerSend: make(chan struct{}, 1),
 		registerer:  registerer,
-		metrics:     metrics,
 	}
 	for _, option := range options {
 		option(mgr)
 	}
+
+	// Register the metrics.
+	// We have to do this after setting all options, so that the name of the Manager is set.
+	if metrics, err := NewMetrics(registerer, mgr.name); err == nil {
+		mgr.metrics = metrics
+	} else {
+		level.Error(logger).Log("msg", "Failed to create discovery manager metrics", "manager", mgr.name, "err", err)
+		return nil
+	}
+
 	return mgr
 }
 
@@ -165,7 +174,7 @@ func (m *Manager) ApplyConfig(cfg map[string]Configs) error {
 	for name, scfg := range cfg {
 		failedCount += m.registerProviders(scfg, name)
 	}
-	m.metrics.FailedConfigs.WithLabelValues(m.name).Set(float64(failedCount))
+	m.metrics.FailedConfigs.Set(float64(failedCount))
 
 	var (
 		wg sync.WaitGroup
@@ -201,7 +210,7 @@ func (m *Manager) ApplyConfig(cfg map[string]Configs) error {
 		// Set metrics and targets for new subs.
 		for s := range prov.newSubs {
 			if _, ok := prov.subs[s]; !ok {
-				m.metrics.DiscoveredTargets.WithLabelValues(m.name, s).Set(0)
+				m.metrics.DiscoveredTargets.WithLabelValues(s).Set(0)
 			}
 			if l := len(refTargets); l > 0 {
 				m.targets[poolKey{s, prov.name}] = make(map[string]*targetgroup.Group, l)
@@ -281,7 +290,7 @@ func (m *Manager) updater(ctx context.Context, p *Provider, updates chan []*targ
 		case <-ctx.Done():
 			return
 		case tgs, ok := <-updates:
-			m.metrics.ReceivedUpdates.WithLabelValues(m.name).Inc()
+			m.metrics.ReceivedUpdates.Inc()
 			if !ok {
 				level.Debug(m.logger).Log("msg", "Discoverer channel closed", "provider", p.name)
 				// Wait for provider cancellation to ensure targets are cleaned up when expected.
@@ -314,11 +323,11 @@ func (m *Manager) sender() {
 		case <-ticker.C: // Some discoverers send updates too often, so we throttle these with the ticker.
 			select {
 			case <-m.triggerSend:
-				m.metrics.SentUpdates.WithLabelValues(m.name).Inc()
+				m.metrics.SentUpdates.Inc()
 				select {
 				case m.syncCh <- m.allGroups():
 				default:
-					m.metrics.DelayedUpdates.WithLabelValues(m.name).Inc()
+					m.metrics.DelayedUpdates.Inc()
 					level.Debug(m.logger).Log("msg", "Discovery receiver's channel was full so will retry the next cycle")
 					select {
 					case m.triggerSend <- struct{}{}:
@@ -370,7 +379,7 @@ func (m *Manager) allGroups() map[string][]*targetgroup.Group {
 		}
 	}
 	for setName, v := range n {
-		m.metrics.DiscoveredTargets.WithLabelValues(m.name, setName).Set(float64(v))
+		m.metrics.DiscoveredTargets.WithLabelValues(setName).Set(float64(v))
 	}
 	return tSets
 }

discovery/manager_test.go

@@ -36,12 +36,6 @@ func TestMain(m *testing.M) {
 	testutil.TolerantVerifyLeak(m)
 }
 
-func newTestDiscoveryMetrics(t *testing.T) *Metrics {
-	metrics, err := NewMetrics(prometheus.NewRegistry())
-	require.NoError(t, err)
-	return metrics
-}
-
 // TestTargetUpdatesOrder checks that the target updates are received in the expected order.
 func TestTargetUpdatesOrder(t *testing.T) {
 	// The order by which the updates are send is determined by the interval passed to the mock discovery adapter
@@ -671,7 +665,8 @@ func TestTargetUpdatesOrder(t *testing.T) {
 			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 			defer cancel()
 
-			discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+			discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+			require.NotNil(t, discoveryManager)
 			discoveryManager.updatert = 100 * time.Millisecond
 
 			var totalUpdatesCount int
@@ -785,7 +780,8 @@ func pk(provider, setName string, n int) poolKey {
 func TestTargetSetTargetGroupsPresentOnConfigReload(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -817,7 +813,8 @@ func TestTargetSetTargetGroupsPresentOnConfigReload(t *testing.T) {
 func TestTargetSetTargetGroupsPresentOnConfigRename(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -852,7 +849,8 @@ func TestTargetSetTargetGroupsPresentOnConfigRename(t *testing.T) {
 func TestTargetSetTargetGroupsPresentOnConfigDuplicateAndDeleteOriginal(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -890,7 +888,8 @@ func TestTargetSetTargetGroupsPresentOnConfigDuplicateAndDeleteOriginal(t *testi
 func TestTargetSetTargetGroupsPresentOnConfigChange(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -951,7 +950,8 @@ func TestTargetSetTargetGroupsPresentOnConfigChange(t *testing.T) {
 func TestTargetSetRecreatesTargetGroupsOnConfigChange(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -990,7 +990,8 @@ func TestTargetSetRecreatesTargetGroupsOnConfigChange(t *testing.T) {
 func TestDiscovererConfigs(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -1022,7 +1023,8 @@ func TestDiscovererConfigs(t *testing.T) {
 func TestTargetSetRecreatesEmptyStaticConfigs(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -1069,7 +1071,8 @@ func TestTargetSetRecreatesEmptyStaticConfigs(t *testing.T) {
 func TestIdenticalConfigurationsAreCoalesced(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, nil, prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, nil, prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -1105,7 +1108,8 @@ func TestApplyConfigDoesNotModifyStaticTargets(t *testing.T) {
 	}
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -1151,7 +1155,8 @@ func (s lockStaticDiscoverer) Run(ctx context.Context, up chan<- []*targetgroup.
 func TestGaugeFailedConfigs(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 
@@ -1307,7 +1312,8 @@ func TestCoordinationWithReceiver(t *testing.T) {
 			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
 			defer cancel()
 
-			mgr := NewManager(ctx, nil, prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+			mgr := NewManager(ctx, nil, prometheus.NewRegistry())
+			require.NotNil(t, mgr)
 			mgr.updatert = updateDelay
 			go mgr.Run()
 
@@ -1402,7 +1408,8 @@ func (o onceProvider) Run(_ context.Context, ch chan<- []*targetgroup.Group) {
 func TestTargetSetTargetGroupsUpdateDuringApplyConfig(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry(), newTestDiscoveryMetrics(t))
+	discoveryManager := NewManager(ctx, log.NewNopLogger(), prometheus.NewRegistry())
+	require.NotNil(t, discoveryManager)
 	discoveryManager.updatert = 100 * time.Millisecond
 	go discoveryManager.Run()
 

discovery/metrics.go

@@ -31,66 +31,64 @@ func init() {
 
 // Metrics to be used with a discovery manager.
 type Metrics struct {
-	FailedConfigs     *prometheus.GaugeVec
+	FailedConfigs     prometheus.Gauge
 	DiscoveredTargets *prometheus.GaugeVec
-	ReceivedUpdates   *prometheus.CounterVec
+	ReceivedUpdates   prometheus.Counter
-	DelayedUpdates    *prometheus.CounterVec
+	DelayedUpdates    prometheus.Counter
-	SentUpdates       *prometheus.CounterVec
+	SentUpdates       prometheus.Counter
 }
 
-func NewMetrics(registerer prometheus.Registerer) (*Metrics, error) {
+func NewMetrics(registerer prometheus.Registerer, sdManagerName string) (*Metrics, error) {
 	m := &Metrics{}
 
-	m.FailedConfigs = prometheus.NewGaugeVec(
+	m.FailedConfigs = prometheus.NewGauge(
 		prometheus.GaugeOpts{
 			Name:        "prometheus_sd_failed_configs",
 			Help:        "Current number of service discovery configurations that failed to load.",
+			ConstLabels: prometheus.Labels{"name": sdManagerName},
 		},
-		[]string{"name"},
 	)
 
 	m.DiscoveredTargets = prometheus.NewGaugeVec(
 		prometheus.GaugeOpts{
 			Name:        "prometheus_sd_discovered_targets",
 			Help:        "Current number of discovered targets.",
+			ConstLabels: prometheus.Labels{"name": sdManagerName},
 		},
-		[]string{"name", "config"},
+		[]string{"config"},
 	)
 
-	m.ReceivedUpdates = prometheus.NewCounterVec(
+	m.ReceivedUpdates = prometheus.NewCounter(
 		prometheus.CounterOpts{
 			Name:        "prometheus_sd_received_updates_total",
 			Help:        "Total number of update events received from the SD providers.",
+			ConstLabels: prometheus.Labels{"name": sdManagerName},
 		},
-		[]string{"name"},
 	)
 
-	m.DelayedUpdates = prometheus.NewCounterVec(
+	m.DelayedUpdates = prometheus.NewCounter(
 		prometheus.CounterOpts{
 			Name:        "prometheus_sd_updates_delayed_total",
 			Help:        "Total number of update events that couldn't be sent immediately.",
+			ConstLabels: prometheus.Labels{"name": sdManagerName},
 		},
-		[]string{"name"},
 	)
 
-	m.SentUpdates = prometheus.NewCounterVec(
+	m.SentUpdates = prometheus.NewCounter(
 		prometheus.CounterOpts{
 			Name:        "prometheus_sd_updates_total",
 			Help:        "Total number of update events sent to the SD consumers.",
+			ConstLabels: prometheus.Labels{"name": sdManagerName},
 		},
-		[]string{"name"},
 	)
 
-	metrics := append(
+	metrics := []prometheus.Collector{
-		[]prometheus.Collector{
 		m.FailedConfigs,
 		m.DiscoveredTargets,
 		m.ReceivedUpdates,
 		m.DelayedUpdates,
 		m.SentUpdates,
-		},
+	}
-		clientGoMetrics()...,
-	)
 
 	for _, collector := range metrics {
 		err := registerer.Register(collector)

discovery/metrics_k8s_client.go

@@ -15,6 +15,7 @@ package discovery
 
 import (
 	"context"
+	"fmt"
 	"net/url"
 	"time"
 
@@ -133,6 +134,16 @@ func clientGoMetrics() []prometheus.Collector {
 	}
 }
 
+func RegisterK8sClientMetricsWithPrometheus(registerer prometheus.Registerer) error {
+	for _, collector := range clientGoMetrics() {
+		err := registerer.Register(collector)
+		if err != nil {
+			return fmt.Errorf("failed to register Kubernetes Go Client metrics: %w", err)
+		}
+	}
+	return nil
+}
+
 func (f *clientGoRequestMetricAdapter) RegisterWithK8sGoClient() {
 	metrics.Register(
 		metrics.RegisterOpts{

documentation/examples/custom-sd/adapter-usage/main.go

@@ -28,10 +28,8 @@ import (
 	"github.com/alecthomas/kingpin/v2"
 	"github.com/go-kit/log"
 	"github.com/go-kit/log/level"
-	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/common/model"
 
-	prom_discovery "github.com/prometheus/prometheus/discovery"
 	"github.com/prometheus/prometheus/discovery/targetgroup"
 	"github.com/prometheus/prometheus/documentation/examples/custom-sd/adapter"
 	"github.com/prometheus/prometheus/util/strutil"
@@ -271,12 +269,11 @@ func main() {
 		fmt.Println("err: ", err)
 	}
 
-	discoveryMetrics, err := prom_discovery.NewMetrics(prometheus.DefaultRegisterer)
 	if err != nil {
 		level.Error(logger).Log("msg", "failed to create discovery metrics", "err", err)
 		os.Exit(1)
 	}
-	sdAdapter := adapter.NewAdapter(ctx, *outputFile, "exampleSD", disc, logger, discoveryMetrics)
+	sdAdapter := adapter.NewAdapter(ctx, *outputFile, "exampleSD", disc, logger)
 	sdAdapter.Run()
 
 	<-ctx.Done()

documentation/examples/custom-sd/adapter/adapter.go

@@ -163,12 +163,12 @@ func (a *Adapter) Run() {
 }
 
 // NewAdapter creates a new instance of Adapter.
-func NewAdapter(ctx context.Context, file, name string, d discovery.Discoverer, logger log.Logger, metrics *discovery.Metrics) *Adapter {
+func NewAdapter(ctx context.Context, file, name string, d discovery.Discoverer, logger log.Logger) *Adapter {
 	return &Adapter{
 		ctx:     ctx,
 		disc:    d,
 		groups:  make(map[string]*customSD),
-		manager: discovery.NewManager(ctx, logger, prometheus.NewRegistry(), metrics),
+		manager: discovery.NewManager(ctx, logger, prometheus.NewRegistry()),
 		output:  file,
 		name:    name,
 		logger:  logger,

documentation/examples/custom-sd/adapter/adapter_test.go

@@ -18,11 +18,9 @@ import (
 	"os"
 	"testing"
 
-	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/common/model"
 	"github.com/stretchr/testify/require"
 
-	"github.com/prometheus/prometheus/discovery"
 	"github.com/prometheus/prometheus/discovery/targetgroup"
 )
 
@@ -228,8 +226,7 @@ func TestWriteOutput(t *testing.T) {
 	require.NoError(t, err)
 	defer os.Remove(tmpfile.Name())
 	tmpfile.Close()
-	metrics, err := discovery.NewMetrics(prometheus.NewRegistry())
 	require.NoError(t, err)
-	adapter := NewAdapter(ctx, tmpfile.Name(), "test_sd", nil, nil, metrics)
+	adapter := NewAdapter(ctx, tmpfile.Name(), "test_sd", nil, nil)
 	require.NoError(t, adapter.writeOutput())
 }