hyperledger/fabric · error

error reading input

Error message

error reading input

What it means

io.ReadAll on the --input file failed while decodeProto was loading the serialized proto. The wrapper "error reading input" indicates an OS-level read problem (closed pipe, permission, or filesystem error), not malformed protobuf content.

Source

Thrown at cmd/configtxlator/main.go:177

	return nil
}

func decodeProto(msgName string, input, output *os.File) error {
	mt, err := protoregistry.GlobalTypes.FindMessageByName(protoreflect.FullName(msgName))
	if err != nil {
		return errors.Wrapf(err, "error encode input")
	}

	msgType := reflect.TypeOf(mt.Zero().Interface())

	if msgType == nil {
		return errors.Errorf("message of type %s unknown", msgType)
	}
	msg := reflect.New(msgType.Elem()).Interface().(proto.Message)

	in, err := io.ReadAll(input)
	if err != nil {
		return errors.Wrapf(err, "error reading input")
	}

	err = proto.Unmarshal(in, msg)
	if err != nil {
		return errors.Wrapf(err, "error unmarshalling")
	}

	err = protolator.DeepMarshalJSON(output, msg)
	if err != nil {
		return errors.Wrapf(err, "error encoding output")
	}

	return nil
}

func computeUpdt(original, updated, output *os.File, channelID string) error {
	origIn, err := io.ReadAll(original)
	if err != nil {

View on GitHub (pinned to 2736b63f8f)

Solutions

1. Check the input path exists and is readable by the current user (ls -l, test -r)
2. If piping, verify the producing command succeeds before configtxlator reads
3. Re-run with correct file mount/permissions in containers
4. Copy the file locally and retry to rule out filesystem/IO issues

Example fix

// before
configtxlator decode --input /etc/hyperledger/config.pb ...
// after
chmod a+r /etc/hyperledger/config.pb && configtxlator decode --input /etc/hyperledger/config.pb ...

// POSIX guard before running
if [ ! -r "$INPUT" ] || [ ! -s "$INPUT" ]; then echo "input missing/unreadable" >&2; exit 1; fi

out, err := decodeCmd.CombinedOutput()
if err != nil {
    var exitErr *exec.ExitError
    if errors.As(err, &exitErr) && strings.Contains(string(out), "error reading input") {
        // fix file path/permissions and retry once
    }
    return err
}

When it happens

Trigger: Input file is unreadable (permissions), a FIFO/pipe closed early, a dangling path passed via shell redirection, or disk/IO error while reading stdin redirect.

Common situations: Running configtxlator in a container without mounting the config file, wrong user permissions after `sudo` generation of channel artifacts, or piping from a command that exited early.

Understand the failure class

Background: "failed to read file", EACCES, ENOENT and "could not read <path>" errors: when a program can't read a file from disk — this error's family across 49 libraries.

Related errors

• error reading original config
• error reading updated config
• error encoding output
• failed to create target folder for connection.json: %s
• error unmarshalling

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/4308afa823147fcb. Report an issue: GitHub.