Add async http instrumentation

CHANGELOG.md

@@ -2,7 +2,12 @@
 
 ## dev
 
-Version <dev> gleans Docker container IDs from cgroups v2-based containers, records additional synthetics attributes, fixes an issue with Rails 7.1 that could cause duplicate log records to be sent to New Relic, and fixes a deprecation warning for the Sidekiq error handler.
+Version <dev> adds instrumentation for Async::HTTP, gleans Docker container IDs from cgroups v2-based containers, records additional synthetics attributes, fixes an issue with Rails 7.1 that could cause duplicate log records to be sent to New Relic, and fixes a deprecation warning for the Sidekiq error handler.
+
+- **Feature: Add instrumentation for Async::HTTP**
+
+  The agent will now record spans for Async::HTTP requests. [PR#2272](https://github.com/newrelic/newrelic-ruby-agent/pull/2272)
+
 
 - **Feature: Prevent the agent from starting in rails commands in Rails 7**
 

lib/new_relic/agent/configuration/default_source.rb

@@ -1379,6 +1379,14 @@ def self.enforce_fallback(allowed_values: nil, fallback: nil)
           :allowed_from_server => false,
           :description => 'Controls auto-instrumentation of `ActiveSupport::Logger` at start up. May be one of: `auto`, `prepend`, `chain`, `disabled`. Used in Rails versions below 7.1.'
         },
+        :'instrumentation.async_http' => {
+          :default => 'auto',
+          :public => true,
+          :type => String,
+          :dynamic_name => true,
+          :allowed_from_server => false,
+          :description => 'Controls auto-instrumentation of Async::HTTP at start up. May be one of: `auto`, `prepend`, `chain`, `disabled`.'
+        },
         :'instrumentation.bunny' => {
           :default => 'auto',
           :public => true,

lib/new_relic/agent/http_clients/async_http_wrappers.rb

@@ -0,0 +1,83 @@
+# This file is distributed under New Relic's license terms.
+# See https://github.com/newrelic/newrelic-ruby-agent/blob/main/LICENSE for complete details.
+# frozen_string_literal: true
+
+require_relative 'abstract'
+require 'resolv'
+
+module NewRelic
+  module Agent
+    module HTTPClients
+      class AsyncHTTPResponse < AbstractResponse
+        def get_status_code
+          get_status_code_using(:status)
+        end
+
+        def [](key)
+          @wrapped_response.headers.to_h[key.downcase]&.first
+        end
+
+        def to_hash
+          @wrapped_response.headers.to_h
+        end
+      end
+
+      class AsyncHTTPRequest < AbstractRequest
+        def initialize(connection, method, url, headers)
+          @connection = connection
+          @method = method
+          @url = ::NewRelic::Agent::HTTPClients::URIUtil.parse_and_normalize_url(url)
+          @headers = headers
+        end
+
+        ASYNC_HTTP = 'Async::HTTP'
+        LHOST = 'host'
+        UHOST = 'Host'
+        COLON = ':'
+
+        def type
+          ASYNC_HTTP
+        end
+
+        def host_from_header
+          if hostname = (self[LHOST] || self[UHOST])
+            hostname.split(COLON).first
+          end
+        end
+
+        def host
+          host_from_header || uri.host.to_s
+        end
+
+        def [](key)
+          return headers[key] unless headers.is_a?(Array)
+
+          headers.each do |header|
+            return header[1] if header[0].casecmp?(key)
+          end
+          nil
+        end
+
+        def []=(key, value)
+          if headers.is_a?(Array)
+            headers << [key, value]
+          else
+            headers[key] = value
+          end
+        end
+
+        def uri
+          @url
+        end
+
+        def headers
+          @headers
+        end
+
+        def method
+          @method
+        end
+      end
+    end
+  end
+end

lib/new_relic/agent/instrumentation/async_http.rb

@@ -0,0 +1,31 @@
+# This file is distributed under New Relic's license terms.
+# See https://github.com/newrelic/newrelic-ruby-agent/blob/main/LICENSE for complete details.
+# frozen_string_literal: true
+
+require_relative 'async_http/instrumentation'
+require_relative 'async_http/chain'
+require_relative 'async_http/prepend'
+
+DependencyDetection.defer do
+  named :'async_http'
+
+  depends_on do
+    # The class that needs to be defined to prepend/chain onto. This can be used
+    # to determine whether the library is installed.
+    defined?(Async::HTTP)
+    # Add any additional requirements to verify whether this instrumentation
+    # should be installed
+  end
+
+  executes do
+    NewRelic::Agent.logger.info('Installing async_http instrumentation')
+
+    require 'async/http/internet'
+    require 'new_relic/agent/http_clients/async_http_wrappers'
+    if use_prepend?
+      prepend_instrument Async::HTTP::Internet, NewRelic::Agent::Instrumentation::AsyncHttp::Prepend
+    else
+      chain_instrument NewRelic::Agent::Instrumentation::AsyncHttp::Chain
+    end
+  end
+end

lib/new_relic/agent/instrumentation/async_http/chain.rb

@@ -0,0 +1,23 @@
+# This file is distributed under New Relic's license terms.
+# See https://github.com/newrelic/newrelic-ruby-agent/blob/main/LICENSE for complete details.
+# frozen_string_literal: true
+
+require_relative 'instrumentation'
+
+module NewRelic::Agent::Instrumentation
+  module AsyncHttp::Chain
+    def self.instrument!
+      ::Async::HTTP::Internet.class_eval do
+        include NewRelic::Agent::Instrumentation::AsyncHttp
+
+        alias_method(:call_without_new_relic, :call)
+
+        def call(method, url, headers = nil, body = nil)
+          call_with_new_relic(method, url, headers, body) do |hdr|
+            call_without_new_relic(method, url, hdr, body)
+          end
+        end
+      end
+    end
+  end
+end

lib/new_relic/agent/instrumentation/async_http/instrumentation.rb

@@ -0,0 +1,35 @@
+# This file is distributed under New Relic's license terms.
+# See https://github.com/newrelic/newrelic-ruby-agent/blob/main/LICENSE for complete details.
+# frozen_string_literal: true
+
+module NewRelic::Agent::Instrumentation
+  module AsyncHttp
+    def call_with_new_relic(method, url, headers = nil, body = nil)
+      headers ||= {} # if it is nil, we need to make it a hash so we can insert headers
+      wrapped_request = NewRelic::Agent::HTTPClients::AsyncHTTPRequest.new(self, method, url, headers)
+
+      segment = NewRelic::Agent::Tracer.start_external_request_segment(
+        library: wrapped_request.type,
+        uri: wrapped_request.uri,
+        procedure: wrapped_request.method
+      )
+
+      begin
+        response = nil
+        segment.add_request_headers(wrapped_request)
+
+        NewRelic::Agent.disable_all_tracing do
+          response = NewRelic::Agent::Tracer.capture_segment_error(segment) do
+            yield(headers)
+          end
+        end
+
+        wrapped_response = NewRelic::Agent::HTTPClients::AsyncHTTPResponse.new(response)
+        segment.process_response_headers(wrapped_response)
+        response
+      ensure
+        segment&.finish
+      end
+    end
+  end
+end

lib/new_relic/agent/instrumentation/async_http/prepend.rb

@@ -0,0 +1,15 @@
+# This file is distributed under New Relic's license terms.
+# See https://github.com/newrelic/newrelic-ruby-agent/blob/main/LICENSE for complete details.
+# frozen_string_literal: true
+
+require_relative 'instrumentation'
+
+module NewRelic::Agent::Instrumentation
+  module AsyncHttp::Prepend
+    include NewRelic::Agent::Instrumentation::AsyncHttp
+
+    def call(method, url, headers = nil, body = nil)
+      call_with_new_relic(method, url, headers, body) { |hdr| super(method, url, hdr, body) }
+    end
+  end
+end

newrelic.yml

@@ -382,7 +382,11 @@ common: &default_settings
   # prepend, chain, disabled.
   # instrumentation.bunny: auto
 
-  # Controls auto-instrumentation of the concurrent-ruby library at start-up. May be
+# Controls auto-instrumentation of Async::HTTP at start up.
+# May be one of [auto|prepend|chain|disabled]
+# instrumentation.async_http: auto
+
+  # Controls auto-instrumentation of the concurrent-ruby library at start up. May be
   # one of: auto, prepend, chain, disabled.
   # instrumentation.concurrent_ruby: auto
 

test/multiverse/suites/async_http/Envfile

@@ -0,0 +1,10 @@
+# This file is distributed under New Relic's license terms.
+# See https://github.com/newrelic/newrelic-ruby-agent/blob/main/LICENSE for complete details.
+# frozen_string_literal: true
+
+instrumentation_methods :chain, :prepend
+
+gemfile <<~RB
+  gem 'async-http'
+  gem 'rack'
+RB

test/multiverse/suites/async_http/async_http_instrumentation_test.rb

@@ -0,0 +1,131 @@
+# This file is distributed under New Relic's license terms.
+# See https://github.com/newrelic/newrelic-ruby-agent/blob/main/LICENSE for complete details.
+# frozen_string_literal: true
+
+require 'http_client_test_cases'
+
+class AsyncHttpInstrumentationTest < Minitest::Test
+  include HttpClientTestCases
+
+  def client_name
+    'Async::HTTP'
+  end
+
+  def timeout_error_class
+    Async::TimeoutError
+  end
+
+  def simulate_error_response
+    Async::HTTP::Client.any_instance.stubs(:call).raises(timeout_error_class.new('read timeout reached'))
+    get_response
+  end
+
+  def get_response(url = nil, headers = nil)
+    request_and_wait(:get, url || default_url, headers)
+  end
+
+  def request_and_wait(method, url, headers = nil, body = nil)
+    resp = nil
+    Async do
+      internet = Async::HTTP::Internet.new
+      resp = internet.send(method, url, headers)
+      @read_resp = resp&.read
+    rescue => e
+      puts "**************************ERROR: #{e}"
+    ensure
+      internet&.close
+    end
+    resp
+  end
+
+  def get_wrapped_response(url)
+    NewRelic::Agent::HTTPClients::AsyncHTTPResponse.new(get_response(url))
+  end
+
+  def head_response
+    request_and_wait(:head, default_url)
+  end
+
+  def post_response
+    request_and_wait(:post, default_url, nil, '')
+  end
+
+  def put_response
+    request_and_wait(:put, default_url, nil, '')
+  end
+
+  def delete_response
+    request_and_wait(:delete, default_url, nil, '')
+  end
+
+  def request_instance
+    NewRelic::Agent::HTTPClients::AsyncHTTPRequest.new(Async::HTTP::Internet.new, 'GET', default_url, {})
+  end
+
+  def response_instance(headers = {})
+    resp = get_response(default_url, headers)
+    headers.each do |k, v|
+      resp.headers[k] = v
+    end
+
+    NewRelic::Agent::HTTPClients::AsyncHTTPResponse.new(resp)
+  end
+
+  def body(res)
+    @read_resp
+  end
+
+  def test_noticed_error_at_segment_and_txn_on_error
+    # skipping this test
+    # Async gem does not allow the errors to escape the async block
+    # so the errors will never end up on the transaction, only ever the async http segment
+  end
+
+  def test_raw_synthetics_header_is_passed_along_if_present_array
+    with_config(:"cross_application_tracer.enabled" => true) do
+      in_transaction do
+        NewRelic::Agent::Tracer.current_transaction.raw_synthetics_header = 'boo'
+
+        get_response(default_url, [%w[itsaheader itsavalue]])
+
+        assert_equal 'boo', server.requests.last['HTTP_X_NEWRELIC_SYNTHETICS']
+      end
+    end
+  end
+
+  def test_raw_synthetics_header_is_passed_along_if_present_hash
+    with_config(:"cross_application_tracer.enabled" => true) do
+      in_transaction do
+        NewRelic::Agent::Tracer.current_transaction.raw_synthetics_header = 'boo'
+
+        get_response(default_url, {'itsaheader' => 'itsavalue'})
+
+        assert_equal 'boo', server.requests.last['HTTP_X_NEWRELIC_SYNTHETICS']
+      end
+    end
+  end
+
+  def test_raw_synthetics_header_is_passed_along_if_present_protocol_header_hash
+    with_config(:"cross_application_tracer.enabled" => true) do
+      in_transaction do
+        NewRelic::Agent::Tracer.current_transaction.raw_synthetics_header = 'boo'
+
+        get_response(default_url, ::Protocol::HTTP::Headers[{'itsaheader' => 'itsavalue'}])
+
+        assert_equal 'boo', server.requests.last['HTTP_X_NEWRELIC_SYNTHETICS']
+      end
+    end
+  end
+
+  def test_raw_synthetics_header_is_passed_along_if_present_protocol_header_array
+    with_config(:"cross_application_tracer.enabled" => true) do
+      in_transaction do
+        NewRelic::Agent::Tracer.current_transaction.raw_synthetics_header = 'boo'
+
+        get_response(default_url, ::Protocol::HTTP::Headers[%w[itsaheader itsavalue]])
+
+        assert_equal 'boo', server.requests.last['HTTP_X_NEWRELIC_SYNTHETICS']
+      end
+    end
+  end
+end

test/multiverse/suites/async_http/config/newrelic.yml

@@ -0,0 +1,19 @@
+---
+development:
+  error_collector:
+    enabled: true
+  apdex_t: 0.5
+  monitor_mode: true
+  license_key: bootstrap_newrelic_admin_license_key_000
+  instrumentation:
+    async_http: <%= $instrumentation_method %>
+  app_name: test
+  log_level: debug
+  host: 127.0.0.1
+  api_host: 127.0.0.1
+  transaction_trace:
+    record_sql: obfuscated
+    enabled: true
+    stack_trace_threshold: 0.5
+    transaction_threshold: 1.0
+  capture_params: false