Excon Sentry tracing and sentry-trace header

README.md

Not yet sure if this is working, but roughly ports built-in Net::HTTP tracing from Sentry to an Excon middleware.

excon_trace.rb

# https://github.com/getsentry/sentry-ruby/blob/07084c5b959d146066af44fb1467af614b9da262/sentry-ruby/lib/sentry/net/http.rb
# https://github.com/excon/excon/blob/master/lib/excon/middlewares/base.rb
require 'excon'

class Excon::Middleware::SentryTrace < Excon::Middleware::Base
  def request_call(datum)
    @span = start_sentry_span

    @stack.request_call(set_entry_trace_header(datum))
  end

  def response_call(datum)
    debugger
    if datum.has_key?(:response)
      record_sentry_breadcrumb(datum)
      record_sentry_span(datum)
    end

    @stack.response_call(datum)
  end

  private def start_sentry_span
    return unless Sentry.initialized?
    return unless span = Sentry.get_current_scope&.get_span
    return if span.sampled == false

    span.start_child(op: Sentry::Net::HTTP::OP_NAME, start_timestamp: Sentry.utc_now.to_f)
  end

  private def set_entry_trace_header(datum)
    headers = datum[:headers] || {}
    if (@span && trace = Sentry.get_current_client.generate_sentry_trace(@span))
      headers[Sentry::SENTRY_TRACE_HEADER_NAME] = trace
    end

    datum.merge(headers: headers)
  end

  private def record_sentry_breadcrumb(datum)
    return unless Sentry.initialized? && Sentry.configuration.breadcrumbs_logger.include?(:http_logger)

    crumb = Sentry::Breadcrumb.new(
      level: :info,
      category: Sentry::Net::HTTP::BREADCRUMB_CATEGORY,
      type: :info,
      data: extract_request_info(datum)
    )
    Sentry.add_breadcrumb(crumb)
  end

  private def record_sentry_span(datum)
    return unless Sentry.initialized? && @span
    request_info = extract_request_info(datum)
    @span.set_description("#{request_info[:method]} #{request_info[:url]}")
    @span.set_data(request_info[:status])
    @span.set_timestamp(Sentry.utc_now.to_f)
  end

  private def extract_request_info(datum)
    {
      url: "#{datum[:scheme]}://#{datum[:host]}:#{datum[:port]}#{datum[:path]}",
      status: datum[:response][:status],
      method: datum[:method].to_s.upcase,
    }
  end
end

Excon.defaults[:middlewares].unshift Excon::Middleware::SentryTrace