{"record":{"id":"c4f3b28f2efd6508","repo":"kubernetes/kops","slug":"error-marshaling-kubeconfig-to-yaml-v","errorCode":null,"errorMessage":"error marshaling kubeconfig to yaml: %v","messagePattern":"error marshaling kubeconfig to yaml: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"upup/pkg/fi/nodeup/nodetasks/kubeconfig.go","lineNumber":127,"sourceCode":"\t\t\t\tName:    \"local\",\n\t\t\t\tCluster: cluster,\n\t\t\t},\n\t\t},\n\t\tContexts: []*kubeconfig.KubectlContextWithName{\n\t\t\t{\n\t\t\t\tName: \"service-account-context\",\n\t\t\t\tContext: kubeconfig.KubectlContext{\n\t\t\t\t\tCluster: \"local\",\n\t\t\t\t\tUser:    k.Name,\n\t\t\t\t},\n\t\t\t},\n\t\t},\n\t\tCurrentContext: \"service-account-context\",\n\t}\n\n\tyaml, err := kops.ToRawYaml(config)\n\tif err != nil {\n\t\treturn fmt.Errorf(\"error marshaling kubeconfig to yaml: %v\", err)\n\t}\n\n\toutput := k.GetConfig()\n\toutput.Resource = fi.NewBytesResource(yaml)\n\n\treturn nil\n}\n","sourceCodeStart":109,"sourceCodeEnd":135,"githubUrl":"https://github.com/kubernetes/kops/blob/4c8573c808a73d578c5eadc86d410646ea0b0d73/upup/pkg/fi/nodeup/nodetasks/kubeconfig.go#L109-L135","documentation":"The kubeconfig task builds an in-memory service-account kubeconfig and serializes it with kops.ToRawYaml; a marshal failure is wrapped here. Since the config is plain maps/slices, this almost always means a value type YAML cannot represent (e.g. func, chan, or unmarshalable type leaked into the config struct).","triggerScenarios":"Run() of the kubeconfig task calls kops.ToRawYaml(config) and it returns an error while producing the service-account kubeconfig.","commonSituations":"Code change introduced a non-serializable field into the kubeconfig struct; customized nodeup build passing unexpected types; nil vs typed mismatch in map values.","solutions":["Inspect the wrapped %v error for the offending field/type","Ensure all fields of the kubeconfig struct are YAML-serializable (strings, ints, maps, slices)","Test ToRawYaml on the constructed config in a unit test to reproduce","Use the stock nodeup binary matching your kOps version rather than a patched one"],"exampleFix":"// before\nconfig.Users[0].Exec = someFunc // non-serializable\n// after\nconfig.Users[0].Exec = map[string]interface{}{\"command\": \"...\"}","handlingStrategy":"try-catch","validationCode":"// ensure the config only holds YAML-safe types before marshaling\nif err := yaml.Unmarshal([]byte(\"{}\"), &config); err != nil { /* struct shape ok */ }","typeGuard":null,"tryCatchPattern":"yamlBytes, err := kops.ToRawYaml(config)\nif err != nil {\n  return fmt.Errorf(\"building service-account kubeconfig failed: %w\", err)\n}","preventionTips":["Keep kubeconfig structs limited to string/map/slice fields","Add a unit test marshaling the kubeconfig struct","Rebuild nodeup from the matching kOps tag when patched"],"tags":["nodeup","kubeconfig","yaml"],"backgroundTag":"yaml-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"}