Class: Datadog::Contrib::Sinatra::TracerMiddleware

Inherits:
Object
  • Object
show all
Defined in:
lib/ddtrace/contrib/sinatra/tracer_middleware.rb

Overview

Middleware used for automatically tagging configured headers and handle request span

Instance Method Summary collapse

Constructor Details

#initialize(app) ⇒ TracerMiddleware

Returns a new instance of TracerMiddleware.



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# File 'lib/ddtrace/contrib/sinatra/tracer_middleware.rb', line 11

def initialize(app)
  @app = app
end

Instance Method Details

#call(env) ⇒ Object 



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# File 'lib/ddtrace/contrib/sinatra/tracer_middleware.rb', line 15

def call(env)
  # Set the trace context (e.g. distributed tracing)
  if configuration[:distributed_tracing] && tracer.provider.context.trace_id.nil?
    context = HTTPPropagator.extract(env)
    tracer.provider.context = context if context.trace_id
  end

  # Begin the trace
  tracer.trace(
    Ext::SPAN_REQUEST,
    service: configuration[:service_name],
    span_type: Datadog::Ext::HTTP::TYPE_INBOUND
  ) do |span|
    Sinatra::Env.set_datadog_span(env, span)

    Sinatra::Env.request_header_tags(env, configuration[:headers][:request]).each do |name, value|
      span.set_tag(name, value) if span.get_tag(name).nil?
    end

    # Run application stack
    status, headers, response_body = @app.call(env)

    Sinatra::Headers.response_header_tags(headers, configuration[:headers][:response]).each do |name, value|
      span.set_tag(name, value) if span.get_tag(name).nil?
    end

    # Set analytics sample rate
    Contrib::Analytics.set_sample_rate(span, analytics_sample_rate) if analytics_enabled?

    [status, headers, response_body]
  end
end