propagator-jaeger: 16 character trace-id isn't zero-padded to 32 characters as per specification

[sid-maddy]

What version of OpenTelemetry are you using?

0.15

What version of Node are you using?

11.8.0

What did you do?

Tried to startSpan in server, expecting the incoming trace to be continued.
Calling service injects trace context using opentracing libraries (e.g. 6ba3280a2610ee73:2eac6cc9a037044f:9a60846c429bf918:1)

Manually zero-padding the trace id and calling setSpanContext() in a custom propagator extending the Jaeger propagator works as expected.

What did you expect to see?

The trace id of the incoming request to be propagated throughout the transaction.

What did you see instead?

A new trace id is generated.

Additional context

As per the propagation format described in Jaeger docs,

trace-id

• Can be variable length, shorter values are 0-padded on the left
• Receivers MUST accept hex-strings shorter than 32 characters and 0-pad them on the left

[sid-maddy]

Bump. @dyladan / @obecny / other members, let me know if this is an expected behaviour of the propagator or an actual issue.

I'd be glad to raise a PR to fix, if it's an issue.

[dyladan]

I think a PR would be welcomed

[vmarchaud]

I've moved the issue to the core repo since the jaeger will be moved to core following #1931