{"record":{"id":"027faecd0db9d3cc","repo":"kubernetes/kops","slug":"buildflagslist-to-reflect-value-s","errorCode":null,"errorMessage":"BuildFlagsList to reflect value: %s","messagePattern":"BuildFlagsList to reflect value: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"pkg/configbuilder/buildconfigfile.go","lineNumber":81,"sourceCode":"\t\t\t}\n\t\t}\n\t\tswitch v := val.Interface().(type) {\n\t\tcase *resource.Quantity:\n\t\t\tfloatVal, err := strconv.ParseFloat(v.AsDec().String(), 64)\n\t\t\tif err != nil {\n\t\t\t\treturn fmt.Errorf(\"unable to convert from Quantity %v to float\", v)\n\t\t\t}\n\t\t\ttargetValue.Set(reflect.ValueOf(&floatVal))\n\t\tdefault:\n\t\t\ttargetValue.Set(val)\n\t\t}\n\n\t\treturn reflectutils.SkipReflection\n\t}\n\n\terr := reflectutils.ReflectRecursive(reflect.ValueOf(options), walker, &reflectutils.ReflectOptions{DeprecatedDoubleVisit: true})\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"BuildFlagsList to reflect value: %s\", err)\n\t}\n\n\tconfigFile, err := yaml.Marshal(target)\n\tif err != nil {\n\t\treturn nil, err\n\t}\n\n\treturn configFile, nil\n}\n\nfunc getValueFromStruct(keyWithDots string, object interface{}) (*reflect.Value, error) {\n\tkeySlice := strings.Split(keyWithDots, \".\")\n\tv := reflect.ValueOf(object)\n\t// iterate through field names, ignoring the first name as it might be the current instance name\n\t// you can make it recursive also if want to support types like slice,map etc along with struct\n\tfor _, key := range keySlice {\n\t\tfor v.Kind() == reflect.Ptr {\n\t\t\tv = v.Elem()","sourceCodeStart":63,"sourceCodeEnd":99,"githubUrl":"https://github.com/kubernetes/kops/blob/4c8573c808a73d578c5eadc86d410646ea0b0d73/pkg/configbuilder/buildconfigfile.go#L63-L99","documentation":"BuildConfigYaml walks the options struct with reflectutils.ReflectRecursive to copy tagged fields into the target config. This error wraps any failure returned by that recursive reflection (including walker errors like the conversion errors above). It is the top-level wrapper meaning \"reflecting the options struct into the config file failed\".","triggerScenarios":"Any walker error during ReflectRecursive over *kops.KubeSchedulerConfig — e.g. a configfile tag naming a missing target field, an invalid Quantity conversion, or reflectutils failing to traverse an unsupported type in the options tree.","commonSituations":"Generating kube-scheduler component config during `kops toolbox`/cluster rendering after a field or tag mismatch was introduced in KubeSchedulerConfig; upstream component-config type changes breaking the tag-to-target mapping.","solutions":["Read the wrapped (%s) inner error to identify which field's conversion or traversal failed","Fix the offending configfile tag or target struct field indicated by the inner error","Run the existing tests (TestParseDefault/TestParse, TestRewriteChannelsManifestForEnroll-style coverage) for BuildConfigYaml to reproduce locally","If reflectutils traversal itself fails on a new type, add a `configfile:\"-\"` tag to skip that subtree"],"exampleFix":"// before\nerr := reflectutils.ReflectRecursive(reflect.ValueOf(options), walker, &reflectutils.ReflectOptions{DeprecatedDoubleVisit: true})\nif err != nil {\n\treturn nil, fmt.Errorf(\"BuildFlagsList to reflect value: %s\", err)\n}\n// after\nerr := reflectutils.ReflectRecursive(reflect.ValueOf(options), walker, &reflectutils.ReflectOptions{DeprecatedDoubleVisit: true})\nif err != nil {\n\treturn nil, fmt.Errorf(\"building scheduler config from options: %w\", err)\n}","handlingStrategy":"try-catch","validationCode":null,"typeGuard":null,"tryCatchPattern":"cfg, err := configbuilder.BuildConfigYaml(options, target)\nif err != nil {\n\tif strings.Contains(err.Error(), \"BuildFlagsList to reflect value\") {\n\t\t// log the wrapped inner cause to find the offending field/tag\n\t\treturn nil, fmt.Errorf(\"config build failed: %w\", err)\n\t}\n\treturn nil, err\n}","preventionTips":["Keep KubeSchedulerConfig tags and the target component-config struct versioned together","Run TestParse/TestParseDefault whenever either struct changes","Use %w instead of %s in wrappers so callers can errors.As/errors.Is on inner causes","Skip unsupported subtrees with configfile:\"-\" tags before they reach the reflection walk"],"tags":["reflection","config-generation","go","kubernetes"],"backgroundTag":"reflection-walk-failed","analyzedSha":"4c8573c808a73d578c5eadc86d410646ea0b0d73","analyzedAt":"2026-09-05T04:13:19.212Z","contentChangedAt":"2026-09-05T04:13:19.212Z","schemaVersion":2},"datasetVersion":"2026-09-12T12:17:11.808Z"}