Review and enhance tracing support for admin service (PHP)

[cartersocha]

The following is a list of requirements that we need to evaluate before declaring v1 for trace telemetry. These requirements are across the entire application; Not all services will meet all requirements. Determine the relevant features for this service.

• Automatic Instrumentation is being used where appropriate.
• Library instrumentation is being used if automatic instrumentation is unavailable.
• Services extend automatic instrumentation.
  • New attributes/events attached to existing spans.
  • New spans are being created from existing spans.
• Automatic and Manual Context Propagation are being demonstrated.
  • Interprocess context propagation is demonstrated.
• Telemetry is not being sampled upfront.
• Telemetry is not being filtered upfront.
• Baggage is being set and read appropriately (i.e., baggage must be explicitly set as attributes on spans)

Referencing: #42

Dependent on this item: #34

[cartersocha]

Tracing is code complete

[julianocosta89]

@cartersocha can we close this one?
The Admin service wasn't implemented but we have PHP as a Quote Service.
I've checked all that we have done in the Quote Service already.

Automatic Instrumentation is not available for PHP: https://github.com/open-telemetry/opentelemetry-php#auto-instrumentation

The only thing missing the Baggage, is that something we want to implement here?

[cartersocha]

@julianocosta89 i think we’re good for v1. I just closed out a bunch of the issues and gave you a quick heads up on slack.
Baggage would be a nice to have but not essential imo

thanks for looking through these!