kubernetes/kops · error

error reading stdin: %v

Error message

error reading stdin: %v

What it means

ConsumeStdin reads all bytes from os.Stdin and wraps any read failure in this error. It is used by commands that accept resources (cluster/instancegroup/secret definitions) via heredocs or pipes. A failure means the stdin stream itself could not be read (I/O error), not that the content was invalid.

Source

Thrown at cmd/kops/root.go:408

		return nil, nil, completions, directive
	}

	clientSet, err = factory.KopsClient()
	if err != nil {
		completions, directive := commandutils.CompletionError("getting clientset", err)
		return nil, nil, completions, directive
	}

	return cluster, clientSet, nil, 0
}

// ConsumeStdin reads all the bytes available from stdin
func ConsumeStdin() ([]byte, error) {
	file := os.Stdin
	buf := new(bytes.Buffer)
	_, err := buf.ReadFrom(file)
	if err != nil {
		return nil, fmt.Errorf("error reading stdin: %v", err)
	}
	return buf.Bytes(), nil
}

View on GitHub (pinned to 4c8573c808)

Solutions

1. Check the command producing the pipe for its own failure (the upstream process may have died mid-stream).
2. Ensure the shell environment has a usable stdin; avoid running inside sandboxes that close fd 0.
3. Write the resource to a file and use -f instead of piping to stdin.
4. Retry the command; transient pipe/EOF conditions usually disappear on a clean re-run.

Example fix

// before
kops create -f - < /dev/null   # stdin closed -> error reading stdin
// after
kops create -f cluster.yaml
# or correctly: cat cluster.yaml | kops create -f -

if [ ! -t 0 ] && [ ! -p /dev/stdin ] && [ ! -f "$RESOURCE_FILE" ]; then echo "no stdin or file input"; exit 1; fi

data, err := ConsumeStdin()
if err != nil {
    return fmt.Errorf("failed to read resource from stdin (is the pipe source healthy?): %w", err)
}

When it happens

Trigger: buf.ReadFrom(os.Stdin) returns an error — e.g. stdin is closed unexpectedly, a pipe breaks, or an I/O device error occurs while commands like kops create, replace, delete, or create secret consume piped/heredoc input.

Common situations: Piping from a command that failed or closed the pipe early (broken pipe); redirecting from an unreadable file descriptor; running in an environment without a valid stdin (detached CI jobs, some IDE terminals); using </dev/null when a definition was expected on stdin.

Related errors

• reading Cilium IPSec config from stdin: %v
• reading from stdin: %v
• encoding resources for %v: %w
• reading expected user-data: %w
• error rending resource %s %v

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/b2b02bbfd9d98063. Report an issue: GitHub.