Class: OpenTelemetry::Propagator::Jaeger::TextMapPropagator

Inherits:
Object
  • Object
show all
Defined in:
lib/opentelemetry/propagator/jaeger/text_map_propagator.rb

Overview

Propagates trace context using the Jaeger format

Instance Method Summary collapse

Instance Method Details

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

Extract trace context from the supplied carrier. If extraction fails, the original context will be returned

Parameters:

  • carrier (Carrier) —

    The carrier to get the header from

  • context (optional Context) (defaults to: Context.current) —

    Context to be updated with the trace context extracted from the carrier. Defaults to Context.current.

  • getter (optional Getter) (defaults to: Context::Propagation.text_map_getter) —

    If the optional getter is provided, it will be used to read the header from the carrier, otherwise the default text map getter will be used.

Returns:

  • (Context) —

    context updated with extracted baggage, or the original context if extraction fails



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# File 'lib/opentelemetry/propagator/jaeger/text_map_propagator.rb', line 46

def extract(carrier, context: Context.current, getter: Context::Propagation.text_map_getter)
  header = getter.get(carrier, IDENTITY_KEY)
  return context unless (match = header.match(TRACE_SPAN_IDENTITY_REGEX))
  return context if match['trace_id'] =~ ZERO_ID_REGEX
  return context if match['span_id'] =~ ZERO_ID_REGEX

  sampling_flags = match['sampling_flags'].to_i
  span = build_span(match, sampling_flags)
  context = Jaeger.context_with_debug(context) if sampling_flags & DEBUG_FLAG_BIT != 0
  context = context_with_extracted_baggage(carrier, context, getter)
  Trace.context_with_span(span, parent_context: context)
end

#fields ⇒ Array<String>

Returns the predefined propagation fields. If your carrier is reused, you should delete the fields returned by this method before calling inject.

Returns:

  • (Array<String>) —

    a list of fields that will be used by this propagator.



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# File 'lib/opentelemetry/propagator/jaeger/text_map_propagator.rb', line 87

def fields
  FIELDS
end

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

Inject trace context into the supplied carrier.

Parameters:

  • carrier (Carrier) —

    The mutable carrier to inject trace context into

  • context (Context) (defaults to: Context.current) —

    The context to read trace context from

  • setter (optional Setter) (defaults to: Context::Propagation.text_map_setter) —

    If the optional setter is provided, it will be used to write context into the carrier, otherwise the default text map setter will be used.



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# File 'lib/opentelemetry/propagator/jaeger/text_map_propagator.rb', line 66

def inject(carrier, context: Context.current, setter: Context::Propagation.text_map_setter)
  span_context = Trace.current_span(context).context
  return unless span_context.valid?

  flags = to_jaeger_flags(context, span_context)
  trace_span_identity_value = [
    span_context.hex_trace_id, span_context.hex_span_id, '0', flags
  ].join(':')
  setter.set(carrier, IDENTITY_KEY, trace_span_identity_value)
  OpenTelemetry.baggage.values(context: context).each do |key, value|
    baggage_key = 'uberctx-' + key
    encoded_value = CGI.escape(value)
    setter.set(carrier, baggage_key, encoded_value)
  end
  carrier
end