{"record":{"id":"ca3987cac0281820","repo":"derailed/k9s","slug":"no-metrics-server-detected-on-cluster","errorCode":null,"errorMessage":"no metrics-server detected on cluster","messagePattern":"no metrics-server detected on cluster","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"warning","filePath":"internal/client/metrics.go","lineNumber":92,"sourceCode":"\t\t\tnodeMetrics[nmx.Items[i].Name] = node\n\t\t}\n\t}\n\n\tvar ccpu, cmem, tcpu, tmem int64\n\tfor _, mx := range nodeMetrics {\n\t\tccpu += mx.CurrentCPU\n\t\tcmem += mx.CurrentMEM\n\t\ttcpu += mx.AllocatableCPU\n\t\ttmem += mx.AllocatableMEM\n\t}\n\tmx.PercCPU, mx.PercMEM = ToPercentage(ccpu, tcpu), ToPercentage(cmem, tmem)\n\n\treturn nil\n}\n\nfunc (m *MetricsServer) checkAccess(ns string, gvr *GVR, msg string) error {\n\tif !m.HasMetrics() {\n\t\treturn errors.New(\"no metrics-server detected on cluster\")\n\t}\n\n\tauth, err := m.CanI(ns, gvr, \"\", ListAccess)\n\tif err != nil {\n\t\treturn err\n\t}\n\tif !auth {\n\t\treturn errors.New(msg)\n\t}\n\treturn nil\n}\n\n// NodesMetrics retrieves metrics for a given set of nodes.\nfunc (*MetricsServer) NodesMetrics(nodes *v1.NodeList, metrics *mv1beta1.NodeMetricsList, mmx NodesMetrics) {\n\tif nodes == nil || metrics == nil {\n\t\treturn\n\t}\n","sourceCodeStart":74,"sourceCodeEnd":110,"githubUrl":"https://github.com/derailed/k9s/blob/2d3ccc6ba2ce98c3781bfc441bb3e884f072774f/internal/client/metrics.go#L74-L110","documentation":"Returned by MetricsServer.checkAccess (internal/client/metrics.go:92) when HasMetrics() reports the cluster does not expose the metrics.k8s.io API. HasMetrics() delegates to supportsMetricsResources(), a discovery call checking for the metrics-server aggregated APIService. The error fires before any RBAC check, on every FetchNodesMetrics/FetchNodeMetrics/FetchPodsMetrics/FetchPodMetrics call, which all funnel through checkAccess.","triggerScenarios":"Calling any metrics fetch (FetchNodesMetrics at metrics.go:155/197, FetchPodsMetrics at :237, FetchPodMetrics at :299) on a cluster without metrics-server installed, with the aggregated APIService unavailable, or while discovery is still populating after cluster startup.","commonSituations":"Minimal/local clusters (kubeadm without addons, kind without the metrics-server addon), metrics-server pod crash-looping or not yet ready, APIService v1beta1.metrics.k8s.io Available=False, RBAC blocking discovery of the API group so it appears absent.","solutions":["Install metrics-server in the cluster and wait for APIService v1beta1.metrics.k8s.io to become Available (kubectl get apiservices)","Check the metrics-server pod logs and readiness: kubectl -n kube-system get pods | grep metrics-server","If RBAC hides the group, grant list/get on apiservices or fix the aggregation-layer certs","Gracefully degrade: treat this error as 'metrics feature unavailable' instead of a hard failure"],"exampleFix":"// before\nmx, err := metricsSrv.FetchNodesMetrics(ctx)\n\n// after\nif !metricsSrv.HasMetrics() {\n    return nil, nil // metrics not deployed; skip pulse view gracefully\n}\nmx, err := metricsSrv.FetchNodesMetrics(ctx)","handlingStrategy":"validation","validationCode":"if !metricsSrv.HasMetrics() {\n    return nil, nil // or a typed 'metrics unavailable' sentinel\n}\nmx, err := metricsSrv.FetchNodesMetrics(ctx)","typeGuard":null,"tryCatchPattern":"mx, err := metricsSrv.FetchNodesMetrics(ctx)\nif err != nil && strings.Contains(err.Error(), \"no metrics-server detected\") {\n    // render UI without metrics columns; do not treat as an error dialog\n}","preventionTips":["Probe HasMetrics() once per connection and cache the result for the session","Install metrics-server as part of cluster bring-up automation so dev/staging parity holds","Check kubectl get apiservices v1beta1.metrics.k8s.io when metrics silently vanish"],"tags":["kubernetes","metrics-server","discovery","rbac"],"backgroundTag":null,"analyzedSha":"2d3ccc6ba2ce98c3781bfc441bb3e884f072774f","analyzedAt":"2026-08-15T16:09:14.432Z","schemaVersion":2},"datasetVersion":"2026-08-15T22:17:37.221Z"}