{"record":{"id":"f86936b71a99fe94","repo":"kubernetes/kops","slug":"unable-to-parse-kubernetes-cluster-api-url-v","errorCode":null,"errorMessage":"unable to parse Kubernetes cluster API URL: %v","messagePattern":"unable to parse Kubernetes cluster API URL: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"pkg/validation/validate_cluster.go","lineNumber":97,"sourceCode":"\nfunc (v *ValidationCluster) addError(failure *ValidationError) {\n\tv.Failures = append(v.Failures, failure)\n}\n\n// ValidationNode represents the validation status for a node\ntype ValidationNode struct {\n\tName     string             `json:\"name,omitempty\"`\n\tZone     string             `json:\"zone,omitempty\"`\n\tRole     string             `json:\"role,omitempty\"`\n\tHostname string             `json:\"hostname,omitempty\"`\n\tStatus   v1.ConditionStatus `json:\"status,omitempty\"`\n}\n\n// hasPlaceHolderIP checks if the API DNS has been updated.\nfunc hasPlaceHolderIP(host string) (string, error) {\n\tapiAddr, err := url.Parse(host)\n\tif err != nil {\n\t\treturn \"\", fmt.Errorf(\"unable to parse Kubernetes cluster API URL: %v\", err)\n\t}\n\thostAddrs, err := net.LookupHost(apiAddr.Hostname())\n\tif err != nil {\n\t\treturn \"\", fmt.Errorf(\"unable to resolve Kubernetes cluster API URL dns: %v\", err)\n\t}\n\n\tsort.Strings(hostAddrs)\n\tfor _, h := range hostAddrs {\n\t\tif h == dns.PlaceholderIP || h == dns.PlaceholderIPv6 {\n\t\t\treturn h, nil\n\t\t}\n\t}\n\n\treturn \"\", nil\n}\n\nfunc NewClusterValidator(cluster *kops.Cluster, cloud fi.Cloud, instanceGroupList *kops.InstanceGroupList, filterInstanceGroups func(ig *kops.InstanceGroup) bool, filterPodsForValidation func(pod *v1.Pod) bool, maxUnreadyNodes int, restConfig *rest.Config, k8sClient kubernetes.Interface) (ClusterValidator, error) {\n\tvar allInstanceGroups []*kops.InstanceGroup","sourceCodeStart":79,"sourceCodeEnd":115,"githubUrl":"https://github.com/kubernetes/kops/blob/4c8573c808a73d578c5eadc86d410646ea0b0d73/pkg/validation/validate_cluster.go#L79-L115","documentation":"hasPlaceHolderIP parses the cluster API URL and checks DNS resolution to detect whether the API DNS record still points at kOps' placeholder IP. This error is returned when the host string cannot be parsed as a URL at all, meaning the cluster spec's KubernetesAPI endpoint is malformed. Validation aborts before any DNS lookup is attempted.","triggerScenarios":"url.Parse(host) fails on the cluster's API URL — the spec.cluster.config API endpoint is empty, contains illegal characters/spaces, or lacks a parseable form (e.g. \"https:// api.example.com\").","commonSituations":"Hand-edited cluster spec with a typo'd or blank kubernetesApi endpoint; environment substitution (e.g. ${KOPS_DNS}) left unexpanded; copying a URL with trailing spaces or a stray character into the cluster YAML.","solutions":["Print the cluster's API URL (kops get cluster -o yaml, look at spec.kubernetesApi.access or the API DNS name) and fix the malformed value with kops edit cluster","Expand any unresolved environment variables before writing the endpoint into the spec","Ensure the URL includes scheme and host, e.g. https://api.<clustername>","Re-run kops validate cluster after correcting the spec"],"exampleFix":"// before (cluster spec / code)\nhost := \"https:// api.mycluster.example.com\" // stray space\nhasPlaceHolderIP(host) // unable to parse Kubernetes cluster API URL: parse \"https:// api...\": invalid character \" \" in host name\n// after\nhost := \"https://api.mycluster.example.com\"\nhasPlaceHolderIP(host)","handlingStrategy":"validation","validationCode":"u, err := url.Parse(host)\nif err != nil || u.Host == \"\" {\n    return fmt.Errorf(\"invalid cluster API URL %q: %v\", host, err)\n}","typeGuard":"func isValidAPIURL(host string) bool {\n    u, err := url.Parse(host)\n    return err == nil && u.Hostname() != \"\"\n}","tryCatchPattern":"ph, err := hasPlaceHolderIP(host)\nif err != nil {\n    return fmt.Errorf(\"validate placeholder IP for %s: %w\", host, err)\n}","preventionTips":["Validate the cluster spec endpoint after any manual edit","Expand environment variables before embedding them in the spec","Keep scheme+host form (https://api.<cluster>) for the API URL"],"tags":["go","dns","url-parsing","kops","validation"],"backgroundTag":"invalid-endpoint-url","analyzedSha":"4c8573c808a73d578c5eadc86d410646ea0b0d73","analyzedAt":"2026-09-05T04:13:19.212Z","contentChangedAt":"2026-09-05T04:13:19.212Z","schemaVersion":2},"datasetVersion":"2026-09-12T07:17:12.445Z"}