Define support for repeated fields in env vars

[jcchavezs]

Right now our env vars don't support repeated fields (aka arrays), we should define if we are going to support them and the way to do it. We could settle on only support repeated for scalar types (e.g. string, bool, enums) because representing objects will be very cumbersome.

Some examples in https://github.com/hypertrace/agent-config/blob/main/config.proto#L26 are:

• HT_PROPAGATION_FORMATS=B3,TRACE_CONTEXT
• HT_PROPAGATION_FORMATS=B3|TRACE_CONTEXT
• HT_PROPAGATION_FORMATS=B3;TRACE_CONTEXT

Ping @hypertrace/agent-maintainers

[mohit-a21]

I agree that we should only support env vars for scalar types only. HT_PROPAGATION_FORMATS=B3,TRACE_CONTEXT For me, I would go for this format.

[davexroth]

, works for me.

[jcchavezs]

any thoughts @pavolloffay ?

[pavolloffay]

HT_PROPAGATION_FORMATS=B3,TRACE_CONTEXT looks the most natural for me