amir20/dozzle · error

invalid format: unexpected key without value

Error message

invalid format: unexpected key without value

What it means

After the final key=value pair the input still contains trailing text where a key is expected (isKey true with unparsed input left). This is a dangling key with no '=' and value, e.g. 'a=1 b', so the line is rejected as malformed logfmt.

Solutions

1. Add a value for the dangling key, e.g. 'a=1 b=2'.
2. Remove the stray trailing token from the log line.
3. If trailing tokens are acceptable upstream, catch the error and parse only the valid prefix or log the line unstructured.

When it happens

Trigger: Thrown at internal/container/logfmt.go:69 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of amir20/dozzle@d9463cbe21 (2026-09-07). Data as JSON: /api/errors/cbe82cb440676a2a. Report an issue: GitHub.

Appendix: source

Thrown at internal/container/logfmt.go:69

				} else if char == ' ' {
					value = log[start:i]
					result.Set(key, value)
					isKey = true
					start = i + 1
				}
			}
		}
	}

	// Handle the last key-value pair if there is no trailing space
	if !isKey && start < len(log) {
		if inQuotes {
			return nil, errors.New("invalid format: unclosed quotes")
		}
		value = log[start:]
		result.Set(key, value)
	} else if isKey && start < len(log) {
		return nil, errors.New("invalid format: unexpected key without value")
	}

	if !isKey {
		if inQuotes {
			return nil, errors.New("invalid format: unclosed quotes")
		}
		value = log[start:]
		result.Set(key, value)
	}

	return result, nil
}

// unescapeQuoted decodes a quoted logfmt value (including the surrounding
// quotes) so escape sequences like \" and \\ produced by logfmt encoders
// (logrus, go-kit, go-logfmt) yield the original text instead of leaking
// backslashes into the parsed value. If the sequence is not decodable, the
// raw content between the quotes is returned unchanged.

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