{"record":{"id":"6a778017b76d5ddd","repo":"kubernetes/kops","slug":"marshaling-to-json-for-v-w","errorCode":null,"errorMessage":"marshaling to json for %v: %w","messagePattern":"marshaling to json for (.+?): %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"pkg/dump/resourcedumper.go","lineNumber":241,"sourceCode":"\t\t\tif err != nil {\n\t\t\t\treturn err\n\t\t\t}\n\t\t\to.SetManagedFields(nil)\n\t\t\tif err := maskObject(obj); err != nil {\n\t\t\t\treturn err\n\t\t\t}\n\t\t\treturn nil\n\t\t})\n\t\tif err != nil {\n\t\t\tresults <- resourceDumpResult{\n\t\t\t\terr: fmt.Errorf(\"creating accessor for %v: %w\", job, err),\n\t\t\t}\n\t\t\tcontinue\n\t\t}\n\t\tcontents, err := resourceList.MarshalJSON()\n\t\tif err != nil {\n\t\t\tresults <- resourceDumpResult{\n\t\t\t\terr: fmt.Errorf(\"marshaling to json for %v: %w\", job, err),\n\t\t\t}\n\t\t\tcontinue\n\t\t}\n\n\t\tswitch d.output {\n\t\tcase \"yaml\":\n\t\t\tcontents, err = yaml.JSONToYAML(contents)\n\t\t\tif err != nil {\n\t\t\t\tresults <- resourceDumpResult{\n\t\t\t\t\terr: fmt.Errorf(\"marshaling to yaml for %v: %w\", job, err),\n\t\t\t\t}\n\t\t\t\tcontinue\n\t\t\t}\n\t\t}\n\t\t_, err = resFile.Write(contents)\n\t\tif err != nil {\n\t\t\tresults <- resourceDumpResult{\n\t\t\t\terr: fmt.Errorf(\"encoding resources for %v: %w\", job, err),","sourceCodeStart":223,"sourceCodeEnd":259,"githubUrl":"https://github.com/kubernetes/kops/blob/4c8573c808a73d578c5eadc86d410646ea0b0d73/pkg/dump/resourcedumper.go#L223-L259","documentation":"After cleaning each item, dumpGVRNamespaces serializes the list with resourceList.MarshalJSON(). If the unstructured list cannot be marshaled to JSON (invalid runtime data, unsupported types), the error is wrapped as \"marshaling to json for %v: %w\". This indicates data corruption or an unserializable object inside the list returned by the API.","triggerScenarios":"resourceList.MarshalJSON() fails because the list returned by the dynamic client contains items with data the JSON encoder cannot handle — e.g. invalid numeric values (NaN), non-string keys in unexpected positions, or corrupted runtime.Unstructured content.","commonSituations":"A CRD or aggregated API server emitting malformed JSON that the client converted to unstructured data poorly; very unusual field types in custom resources; a Go-side encoding/json failure on objects with unexpected shapes (maps with non-string keys).","solutions":["Inspect the offending resource (given by the %v job in the error) with `kubectl get -o json` to find the malformed field.","Fix or remove the malformed CRD instance / aggregated API response.","Upgrade kOps and k8s.io/apimachinery — many marshal edge cases were fixed upstream.","Work around by dumping with a different output format or excluding that resource, then file an issue."],"exampleFix":"// before\ncontents, err := resourceList.MarshalJSON()\n// after (log which item fails)\ncontents, err := resourceList.MarshalJSON()\nif err != nil {\n  klog.Warningf(\"skipping %v: %v\", job, err)\n  continue\n}","handlingStrategy":"try-catch","validationCode":"// Sanity-check the resource is JSON-serializable before dumping\nlist, err := dynamicClient.Resource(gvr).Namespace(ns).List(ctx, metav1.ListOptions{})\nif err == nil {\n  if _, err := list.MarshalJSON(); err != nil {\n    log.Printf(\"skipping %v: not JSON-serializable: %v\", gvr, err)\n  }\n}","typeGuard":null,"tryCatchPattern":"if err := dump(); err != nil {\n  if strings.Contains(err.Error(), \"marshaling to json for\") {\n    // fall back to raw bytes from the API (kubectl get --raw) or skip the resource\n  }\n  return err\n}","preventionTips":["Validate custom resource instances (kubeconform/kubectl apply --dry-run) so malformed data never reaches dumps.","Keep sigs.k8s.io/yaml and apimachinery versions current.","Watch for non-string map keys or NaN values in CRs served by aggregated apiservers.","Test dumps against staging clusters with representative CRD data."],"tags":["json","serialization","kubernetes","dynamic-client"],"backgroundTag":"json-marshal-failed","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"}