{"record":{"id":"c35eb085d967ae23","repo":"kubernetes/kops","slug":"cannot-render-instance-groups-for-q-w","errorCode":null,"errorMessage":"cannot render instance groups for %q: %w","messagePattern":"cannot render instance groups for %q: %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"cmd/kops/validate_cluster.go","lineNumber":280,"sourceCode":"\t\treturn string(c.Spec.Role)\n\t})\n\tt.AddColumn(\"MACHINETYPE\", func(c kopsapi.InstanceGroup) string {\n\t\treturn c.Spec.MachineType\n\t})\n\tt.AddColumn(\"SUBNETS\", func(c kopsapi.InstanceGroup) string {\n\t\treturn strings.Join(c.Spec.Subnets, \",\")\n\t})\n\tt.AddColumn(\"MIN\", func(c kopsapi.InstanceGroup) string {\n\t\treturn int32PointerToString(c.Spec.MinSize)\n\t})\n\tt.AddColumn(\"MAX\", func(c kopsapi.InstanceGroup) string {\n\t\treturn int32PointerToString(c.Spec.MaxSize)\n\t})\n\n\tfmt.Fprintln(out, \"INSTANCE GROUPS\")\n\terr := t.Render(instanceGroups, out, \"NAME\", \"ROLE\", \"MACHINETYPE\", \"MIN\", \"MAX\", \"SUBNETS\")\n\tif err != nil {\n\t\treturn fmt.Errorf(\"cannot render instance groups for %q: %w\", cluster.Name, err)\n\t}\n\n\t{\n\t\tnodeTable := &tables.Table{}\n\t\tnodeTable.AddColumn(\"NAME\", func(n *validation.ValidationNode) string {\n\t\t\treturn n.Name\n\t\t})\n\n\t\tnodeTable.AddColumn(\"READY\", func(n *validation.ValidationNode) v1.ConditionStatus {\n\t\t\treturn n.Status\n\t\t})\n\n\t\tnodeTable.AddColumn(\"ROLE\", func(n *validation.ValidationNode) string {\n\t\t\treturn n.Role\n\t\t})\n\n\t\tfmt.Fprintln(out, \"\\nNODE STATUS\")\n\t\tif err := nodeTable.Render(result.Nodes, out, \"NAME\", \"ROLE\", \"READY\"); err != nil {","sourceCodeStart":262,"sourceCodeEnd":298,"githubUrl":"https://github.com/kubernetes/kops/blob/4c8573c808a73d578c5eadc86d410646ea0b0d73/cmd/kops/validate_cluster.go#L262-L298","documentation":"Thrown by validateClusterOutputTable when the tabular writer (tables.Table.Render) fails while rendering the INSTANCE GROUPS section of `kops validate cluster` output. The instance-group slice cannot be converted to the requested table columns. The underlying renderer error is wrapped with the cluster name for context.","triggerScenarios":"Calling `kops validate cluster --output table` (the default output path) when t.Render(instanceGroups, out, ...) returns an error — e.g. an I/O error writing to the output writer, or a renderer-level failure processing the instance group rows.","commonSituations":"Piping CLI output into a closed pipe (e.g. `kops validate cluster | head` causing EPIPE); output redirected to a full disk or closed file descriptor; programmatically injected writer failures in tests.","solutions":["Re-run the command and avoid closing the receiving pipe early (e.g. don't pipe into `head`).","Check disk space and that the output target (file/tty) is writable.","Use `--output json` or `--output yaml` to bypass table rendering entirely.","If persistent, capture the wrapped inner error (after `: `) to identify the root renderer failure."],"exampleFix":"// before\nkops validate cluster | head -5\n// after\nkops validate cluster --output json > validation.json","handlingStrategy":"fallback","validationCode":null,"typeGuard":null,"tryCatchPattern":"// Go: handle wrapped render error\nif err := RunValidateCluster(ctx, f, out, options); err != nil {\n    if strings.Contains(err.Error(), \"cannot render instance groups\") {\n        // fall back to structured output\n        return runValidateClusterJSON(...) \n    }\n    return err\n}","preventionTips":["Avoid piping kops output into consumers that close the pipe early.","Write validation output to files in scripts, not directly to volatile pipes.","Keep disk space available on hosts running kops.","Use --output json for machine consumption instead of tables."],"tags":["kops","cli","table-rendering","output"],"backgroundTag":"table-render-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"}