Audit Compliance: Common Attribute for Logs

[pellared]

1. Review the Attribute section of the Common specification for all Stable normative statements relevant to the Logs API and Logs SDK packages.
2. Audit the attribute, logs API, and logs SDK packages for compliance with the specified Stable normative statements.
3. Do not include the Attribute representation for non-OTLP subsection because it is marked Status: Development.
4. Identify existing issues or create new issues to track any work needed to make the implementation compliant with the Stable specification.

[pellared]

Verdict

NONCOMPLIANT. Empty top-level attribute keys are recognized as invalid by the shared attribute package but are not rejected by the Logs API or SDK. They can survive LogRecord and Instrumentation Scope processing and be emitted by exporters.

Focused bug #8795 now tracks the required implementation work. Issue #8553 can close as an audited overlap after linking #8795.

Scope

• Implementation: 0de413a3.
• Stable Common Attribute requirements: common/README.md at 041241bf.

The Stable specification defines an Attribute as a key-value pair whose key MUST be a non-null, non-empty string with case sensitivity preserved and whose value MUST be an AnyValue (specification). Go strings cannot be null, so the relevant invalid state is an empty string.

Validation exists but is not applied to Logs

The shared attribute package exposes the correct validity predicate: Key.Defined reports false for an empty key, and KeyValue.Valid delegates to it (attribute/key.go, attribute/kv.go). The Logs paths do not invoke this validation.

Empty-key propagation

1. API Record.AddAttributes appends every supplied KeyValue without calling Valid (log/record.go).
2. SDK Record.AddAttributes and SetAttributes perform deduplication, normalization, and limit handling but do not reject invalid keys (AddAttributes, SetAttributes).
3. SDK tests explicitly preserve ten empty-key attributes when duplicate retention is enabled and one deduplicated empty-key attribute in the default mode (duplicate mode, default mode).
4. WithInstrumentationAttributes constructs an attribute.Set without a filter, and attribute.NewSet passes a nil filter to the set constructor (Logger option, attribute.NewSet). The SDK provider normalizes nested map duplicates but does not filter invalid top-level Scope attributes (sdk/log/provider.go).
5. The OTLP transformation copies exact key text into protocol KeyValue messages for both Instrumentation Scope and LogRecord attributes, without validation (Scope transformation, attribute transformation). The stdout exporter likewise copies the SDK attribute collections directly (stdoutlog/record.go).

Resource handling provides an existing repository precedent for the required validation: resource.NewSchemaless constructs its set with a kv.Valid() filter and discards invalid entries (sdk/resource/resource.go).

Compliant Attribute properties

Non-empty key case is preserved exactly throughout the attribute, Logs, and exporter paths. Attribute values use the closed attribute.Value representation that covers the Stable AnyValue types. The failure is limited to enforcing the non-empty top-level key requirement.

Focused bug

Bug #8795 covers both invalid-key paths identified here: LogRecord attributes and Instrumentation Scope attributes. Its acceptance criteria require preventing empty keys from reaching processors or exporters, adding API-to-export regression coverage, preserving valid key case and values, and explicitly deciding whether rejected invalid entries affect DroppedAttributes or diagnostics.