ahmetb/kubectx · error

failed to write temp kubeconfig: %w

Error message

failed to write temp kubeconfig: %w

What it means

Wrapper error in transformKubeconfig: writing the original kubeconfig bytes to the temp file failed (short write or I/O error). The temp file is closed and removed before returning; the readonly shell setup aborts with the cause wrapped in %w.

Source

Thrown at cmd/kubectx/readonly_shell.go:59

			fmt.Fprintf(w, "%s kubectl context is %s in READ-ONLY mode — type 'exit' to leave.\n",
				badgeColor.Sprint("[READONLY SHELL]"), printer.WarningColor.Sprint(ctxName))
		},
		printExit: func(w io.Writer, prevCtx string) {
			fmt.Fprintf(w, "%s kubectl context is now %s.\n",
				badgeColor.Sprint("[READONLY SHELL EXITED]"), printer.WarningColor.Sprint(prevCtx))
		},
		transformKubeconfig: func(data []byte) ([]byte, func(), error) {
			// Write original kubeconfig to temp file for the proxy to load TLS/auth.
			origFile, err := os.CreateTemp("", "kubectx-readonly-orig-*.yaml")
			if err != nil {
				return nil, nil, fmt.Errorf("failed to create temp kubeconfig file: %w", err)
			}
			origPath := origFile.Name()

			if _, err := origFile.Write(data); err != nil {
				origFile.Close()
				os.Remove(origPath)
				return nil, nil, fmt.Errorf("failed to write temp kubeconfig: %w", err)
			}
			origFile.Close()

			// Start the readonly proxy.
			p, err := proxy.Start(proxy.Config{
				KubeconfigPath: origPath,
				ContextName:    op.Target,
			})
			if err != nil {
				os.Remove(origPath)
				return nil, nil, fmt.Errorf("failed to start readonly proxy: %w", err)
			}

			// Rewrite kubeconfig to point to the proxy.
			rewritten, err := proxy.RewriteKubeconfig(data, p.Addr())
			if err != nil {
				p.Shutdown(context.Background())
				os.Remove(origPath)

View on GitHub (pinned to 12ad6fb22e)

Solutions

1. Check disk space and temp directory health
2. Retry the readonly shell after resolving the I/O error

When it happens

Trigger: Thrown at cmd/kubectx/readonly_shell.go:59 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of ahmetb/kubectx@12ad6fb22e (2026-09-02). Data as JSON: /api/errors/b7bbf13ecb2fc98c. Report an issue: GitHub.