Class: Datadog::AppSec::Contrib::Rack::RequestMiddleware

Inherits:
Object
  • Object
show all
Defined in:
lib/datadog/appsec/contrib/rack/request_middleware.rb

Overview

Topmost Rack middleware for AppSec This should be inserted just below Datadog::Tracing::Contrib::Rack::TraceMiddleware

Instance Method Summary collapse

Constructor Details

#initialize(app, opt = {}) ⇒ RequestMiddleware

Returns a new instance of RequestMiddleware.



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# File 'lib/datadog/appsec/contrib/rack/request_middleware.rb', line 35

def initialize(app, opt = {})
  @app = app

  @oneshot_tags_sent = false
  @rack_headers = {}
end

Instance Method Details

#call(env) ⇒ Object

rubocop:disable Metrics/MethodLength



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# File 'lib/datadog/appsec/contrib/rack/request_middleware.rb', line 43

def call(env)
  return @app.call(env) unless Datadog::AppSec.enabled?

  boot = Datadog::Core::Remote::Tie.boot
  Datadog::Core::Remote::Tie::Tracing.tag(boot, active_span)

  # For a given request, keep using the first Rack stack scope for
  # nested apps. Don't set `context` local variable so that on popping
  # out of this nested stack we don't finalize the parent's context
  return @app.call(env) if active_context(env)

  security_engine = Datadog::AppSec.security_engine

  # TODO: handle exceptions, except for @app.call
  return @app.call(env) unless security_engine

  ctx = Datadog::AppSec::Context.activate(
    Datadog::AppSec::Context.new(active_trace, active_span, security_engine.new_runner)
  )
  env[Datadog::AppSec::Ext::CONTEXT_KEY] = ctx

  add_appsec_tags(ctx)
  add_request_tags(ctx, env)

  http_response = nil
  gateway_request = Gateway::Request.new(env)
  gateway_response = nil

  interrupt_params = catch(::Datadog::AppSec::Ext::INTERRUPT) do
    # TODO: This event should be renamed into `rack.request.start` to
    #       reflect that it's the beginning of the request-cycle
    http_response, _gateway_request = Instrumentation.gateway.push('rack.request', gateway_request) do
      @app.call(env)
    end

    gateway_response = Gateway::Response.new(
      http_response[2], http_response[0], http_response[1], context: ctx
    )

    Instrumentation.gateway.push('rack.request.finish', gateway_request)
    Instrumentation.gateway.push('rack.response', gateway_response)

    nil
  end

  if interrupt_params
    ctx.mark_as_interrupted!
    http_response = AppSec::Response.from_interrupt_params(interrupt_params, env['HTTP_ACCEPT']).to_rack
  end

  # NOTE: This is not optimal, but in the current implementation
  #       `gateway_response` is a container to dispatch response event
  #       and in case of interruption it suppose to be `nil`.
  #
  #       `http_response` is a real response object in both cases, but
  #       to save us some computations, we will use already pre-computed
  #       `gateway_response` instead of re-creating it.
  #
  # WARNING: This part will be refactored.
  tmp_response = if interrupt_params
    Gateway::Response.new(http_response[2], http_response[0], http_response[1], context: ctx)
  else
    gateway_response
  end

  if AppSec::APISecurity.enabled? && AppSec::APISecurity.sample_trace?(ctx.trace) &&
      AppSec::APISecurity.sample?(gateway_request.request, tmp_response.response)
    ctx.events.push(
      AppSec::SecurityEvent.new(ctx.extract_schema, trace: ctx.trace, span: ctx.span)
    )
  end

  AppSec::Event.record(ctx, request: gateway_request, response: gateway_response)

  http_response
ensure
  if ctx
    ctx.export_metrics
    ctx.export_request_telemetry

    Datadog::AppSec::Context.deactivate
  end
end