[owent]

Fixes #3487

Changes

• Add bytes support for OTLP recordables.

The API interface support long time ago, but after the protos are updated, we seem to forget to implement it.
See open-telemetry/opentelemetry-specification#780 and open-telemetry/opentelemetry-proto#297 for details.

For significant contributions please make sure you have completed the following items:

• CHANGELOG.md updated for non-trivial changes
• Unit tests have been added
• Changes in public API reviewed

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[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 89.96%. Comparing base (7059f73) to head (55a31a3).
Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3495      +/-   ##
==========================================
+ Coverage   89.95%   89.96%   +0.02%     
==========================================
  Files         219      219              
  Lines        7051     7051              
==========================================
+ Hits         6342     6343       +1     
+ Misses        709      708       -1     

see 1 file with indirect coverage changes

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[dbarker]

LGTM. Thanks.

[lalitb]

Unfortunately, as a side effect, this change also enables support for populating byte/uint8 types as span attribute values, which is inconsistent with the specs:

https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/common/README.md#attribute

Per the spec, an attribute value MUST be one of the following:

• string
• boolean
• double (IEEE 754)
• signed 64-bit integer
• Or an array of the above types (array must be homogeneous)

Supporting raw bytes or uint8 is not permitted for span attributes.

It’s better to enable populating uint8_t as OTLP attributes or body only for logs, not for spans.
Alternatively, instead of this PR, document that byte data should be encoded as base64 and set as a string attribute. The custom exporter or backend can handle base64 decoding if needed.

[lalitb]

As mentioned - #3495 (comment)

[owent]

Unfortunately, as a side effect, this change also enables support for populating byte/uint8 types as span attribute values, which is inconsistent with the specs:

https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/common/README.md#attribute

Per the spec, an attribute value MUST be one of the following:

• string
• boolean
• double (IEEE 754)
• signed 64-bit integer
• Or an array of the above types (array must be homogeneous)

Supporting raw bytes or uint8 is not permitted for span attributes.

It’s better to enable populating uint8_t as OTLP attributes or body only for logs, not for spans. Alternatively, instead of this PR, document that byte data should be encoded as base64 and set as a string attribute. The custom exporter or backend can handle base64 decoding if needed.

Thanks, only log record use bytes now.

[lalitb]

Thanks.