Class: Datadog::OpenTelemetry::SDK::Propagator

Inherits:
Object
  • Object
show all
Defined in:
lib/datadog/opentelemetry/sdk/propagator.rb

Overview

Compatibility wrapper to allow Datadog propagators to fulfill the OpenTelemetry propagator API.

Instance Method Summary collapse

Constructor Details

#initialize(datadog_propagator) ⇒ Propagator

Returns a new instance of Propagator.



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# File 'lib/datadog/opentelemetry/sdk/propagator.rb', line 9

def initialize(datadog_propagator)
  @datadog_propagator = datadog_propagator
end

Instance Method Details

#extract(carrier, context: ::OpenTelemetry::Context.current, getter: ::OpenTelemetry::Context::Propagation.text_map_getter) ⇒ Object 



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# File 'lib/datadog/opentelemetry/sdk/propagator.rb', line 29

def extract(
  carrier, context: ::OpenTelemetry::Context.current,
  getter: ::OpenTelemetry::Context::Propagation.text_map_getter
)
  if getter != ::OpenTelemetry::Context::Propagation.text_map_getter &&
      getter != ::OpenTelemetry::Common::Propagation.rack_env_getter
    # PENDING: Not to report telemetry logs for now
    Datadog.logger.error(
      "Custom getter #{getter} is not supported. Please inform the `datadog` team at " \
    ' https://github.com/DataDog/dd-trace-rb of your use case so we can best support you. Using the default ' \
    'OpenTelemetry::Context::Propagation.text_map_getter as a fallback getter.'
    )
  end

  digest = @datadog_propagator.extract(carrier)
  return context unless digest

  # Converts the {Numeric} Datadog id object to OpenTelemetry's byte array format.
  # 128-bit unsigned, big-endian integer
  trace_id = [digest.trace_id >> 64, digest.trace_id & 0xFFFFFFFFFFFFFFFF].pack('Q>Q>')
  # 64-bit unsigned, big-endian integer
  span_id = [digest.span_id].pack('Q>')

  if digest.trace_state || digest.trace_flags
    trace_flags = ::OpenTelemetry::Trace::TraceFlags.from_byte(digest.trace_flags)
    tracestate = Tracing::Distributed::TraceContext.new(fetcher: nil).send(:build_tracestate, digest)
  else
    trace_flags = if Tracing::Sampling::PrioritySampler.sampled?(digest.trace_sampling_priority)
                    ::OpenTelemetry::Trace::TraceFlags::SAMPLED
                  else
                    ::OpenTelemetry::Trace::TraceFlags::DEFAULT
                  end
    tracestate = ::OpenTelemetry::Trace::Tracestate::DEFAULT
  end

  span_context = ::OpenTelemetry::Trace::SpanContext.new(
    trace_id: trace_id,
    span_id: span_id,
    trace_flags: trace_flags,
    tracestate: tracestate,
    remote: true
  )

  span = ::OpenTelemetry::Trace.non_recording_span(span_context)

  trace = Tracing.continue_trace!(digest)

  span.datadog_trace = trace

  ::OpenTelemetry::Trace.context_with_span(span, parent_context: context)
end

#fields ⇒ Object

Returns fields set by this propagator. DEV: Doesn’t seem like it’s used in production Otel code paths.



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# File 'lib/datadog/opentelemetry/sdk/propagator.rb', line 83

def fields
  []
end

#inject(carrier, context: ::OpenTelemetry::Context.current, setter: ::OpenTelemetry::Context::Propagation.text_map_setter) ⇒ Object 



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# File 'lib/datadog/opentelemetry/sdk/propagator.rb', line 13

def inject(
  carrier, context: ::OpenTelemetry::Context.current,
  setter: ::OpenTelemetry::Context::Propagation.text_map_setter
)
  unless setter == ::OpenTelemetry::Context::Propagation.text_map_setter
    # PENDING: Not to report telemetry logs for now
    Datadog.logger.error(
      'Custom setter is not supported. Please inform the `datadog` team at ' \
    ' https://github.com/DataDog/dd-trace-rb of your use case so we can best support you. Using the default ' \
    'OpenTelemetry::Context::Propagation.text_map_setter as a fallback setter.'
    )
  end

  @datadog_propagator.inject(context.trace.to_digest, carrier)
end