add sidekiq integration

.rubocop.yml

@@ -47,3 +47,6 @@ Metrics/CyclomaticComplexity:
 
 Metrics/PerceivedComplexity:
   Max: 15
+
+Lint/UnusedMethodArgument:
+    Enabled: false

Appraisals

@@ -66,4 +66,5 @@ appraise "contrib" do
   gem "hiredis"
   gem "rack-test"
   gem "sinatra"
+  gem "sidekiq"
 end

Rakefile

@@ -6,7 +6,7 @@ require 'appraisal'
 require 'yard'
 
 namespace :test do
-  task all: [:main, :rails, :railsredis, :elasticsearch, :http, :redis, :sinatra, :monkey]
+  task all: [:main, :rails, :railsredis, :elasticsearch, :http, :redis, :sidekiq, :sinatra, :monkey]
 
   Rake::TestTask.new(:main) do |t|
     t.libs << %w(test lib)
@@ -30,7 +30,7 @@ namespace :test do
     t.test_files = FileList['test/contrib/rails/**/*redis*_test.rb']
   end
 
-  [:elasticsearch, :http, :redis, :sinatra].each do |contrib|
+  [:elasticsearch, :http, :redis, :sinatra, :sidekiq].each do |contrib|
     Rake::TestTask.new(contrib) do |t|
       t.libs << %w(test lib)
       t.test_files = FileList["test/contrib/#{contrib}/*_test.rb"]
@@ -114,6 +114,7 @@ task :ci do
     sh 'rvm $MRI_VERSIONS --verbose do appraisal contrib rake test:http'
     sh 'rvm $MRI_VERSIONS --verbose do appraisal contrib rake test:redis'
     sh 'rvm $MRI_VERSIONS --verbose do appraisal contrib rake test:sinatra'
+    sh 'rvm $MRI_VERSIONS --verbose do appraisal contrib rake test:sidekiq'
   when 2
     sh 'rvm $RAILS_VERSIONS --verbose do appraisal rails3-postgres rake test:rails'
     sh 'rvm $RAILS_VERSIONS --verbose do appraisal rails3-mysql2 rake test:rails'

docs/GettingStarted.md

@@ -175,6 +175,47 @@ Net::HTTP module.
 
     content = Net::HTTP.get(URI('http://127.0.0.1/index.html'))
 
+### Sidekiq
+
+The Sidekiq integration is a server-side middleware which will trace job
+executions. It can be added as any other Sidekiq middleware:
+
+    require 'sidekiq'
+    require 'ddtrace'
+    require 'ddtrace/contrib/sidekiq/tracer'
+
+    Sidekiq.configure_server do |config|
+      config.server_middleware do |chain|
+        chain.add(Datadog::Contrib::Sidekiq::Tracer, debug: true)
+      end
+    end
+
+#### Configure the tracer
+
+To modify the default configuration, simply pass arguments to the middleware.
+For example, to change the default service name and activate the debug mode:
+
+    Sidekiq.configure_server do |config|
+      config.server_middleware do |chain|
+        chain.add(Datadog::Contrib::Sidekiq::Tracer,
+                  default_service: 'my_app', debug: true)
+      end
+    end
+
+Available settings are:
+
+* ``enabled``: define if the ``tracer`` is enabled or not. If set to
+  ``false``, the code is still instrumented but no spans are sent to the local
+  trace agent.
+* ``default_service``: set the service name used when tracing application
+  requests. Defaults to ``sidekiq``.
+* ``tracer``: set the tracer to use. Usually you don't need to change that
+  value unless you're already using a different initialized tracer somewhere
+  else.
+* ``debug``: set to ``true`` to enable debug logging.
+* ``trace_agent_hostname``: set the hostname of the trace agent.
+* ``trace_agent_port``: set the port the trace agent is listening on.
+
 ## Advanced usage
 
 ### Manual Instrumentation
@@ -360,6 +401,10 @@ The currently supported web server are:
 
 Currently we are supporting Sinatra >= 1.4.0.
 
+#### Sidekiq versions
+
+Currently we are supporting Sidekiq >= 4.0.0.
+
 ### Glossary
 
 * ``Service``: The name of a set of processes that do the same job. Some examples are ``datadog-web-app`` or ``datadog-metrics-db``.

lib/ddtrace/contrib/sidekiq/tracer.rb

@@ -0,0 +1,52 @@
+
+require 'sidekiq/api'
+
+require 'ddtrace/ext/app_types'
+
+sidekiq_vs = Gem::Version.new(Sidekiq::VERSION)
+sidekiq_min_vs = Gem::Version.new('4.0.0')
+if sidekiq_vs < sidekiq_min_vs
+  raise "sidekiq version #{sidekiq_vs} is not supported yet " \
+        + "(supporting versions >=#{sidekiq_min_vs})"
+end
+
+Datadog::Tracer.log.info("activating instrumentation for sidekiq #{sidekiq_vs}")
+
+module Datadog
+  module Contrib
+    module Sidekiq
+      # Middleware is a Sidekiq server-side middleware which traces executed
+      # jobs.
+      class Tracer
+        def initialize(options)
+          @enabled = options.fetch(:enabled, true)
+          @default_service = options.fetch(:default_service, 'sidekiq')
+          @tracer = options.fetch(:tracer, Datadog.tracer)
+          @debug = options.fetch(:debug, false)
+          @trace_agent_hostname = options.fetch(:trace_agent_hostname,
+                                                Datadog::Writer::HOSTNAME)
+          @trace_agent_port = options.fetch(:trace_agent_port,
+                                            Datadog::Writer::PORT)
+
+          Datadog::Tracer.debug_logging = @debug
+
+          @tracer.enabled = @enabled
+          @tracer.set_service_info(@default_service, 'sidekiq',
+                                   Datadog::Ext::AppTypes::JOB_PROCESSOR)
+        end
+
+        def call(worker, job, queue)
+          return yield unless @enabled
+
+          @tracer.trace('sidekiq.job',
+                        service: @default_service, span_type: 'job') do |span|
+            span.resource = job['class']
+            span.set_tag('sidekiq.job.queue', job['queue'])
+
+            yield
+          end
+        end
+      end
+    end
+  end
+end

lib/ddtrace/ext/app_types.rb

@@ -4,6 +4,7 @@ module AppTypes
       WEB = 'web'.freeze
       DB = 'db'.freeze
       CACHE = 'cache'.freeze
+      JOB_PROCESSOR = 'job_processor'.freeze
     end
   end
 end

test/contrib/sidekiq/disabled_tracer_test.rb

@@ -0,0 +1,28 @@
+
+require 'contrib/sidekiq/tracer_test_base'
+
+class DisabledTracerTest < TracerTestBase
+  class EmptyWorker
+    include Sidekiq::Worker
+
+    def perform()
+    end
+  end
+
+  def setup
+    super
+
+    Sidekiq::Testing.server_middleware do |chain|
+        chain.add(Datadog::Contrib::Sidekiq::Tracer,
+                  tracer: @tracer, enabled: false)
+    end
+  end
+
+  def test_empty
+    EmptyWorker.perform_async()
+
+    spans = @writer.spans()
+    assert_equal(0, spans.length)
+  end
+end
+

test/contrib/sidekiq/tracer_test.rb

@@ -0,0 +1,63 @@
+
+require 'contrib/sidekiq/tracer_test_base'
+
+class TracerTest < TracerTestBase
+  class TestError < StandardError; end
+
+  class EmptyWorker
+    include Sidekiq::Worker
+
+    def perform()
+    end
+  end
+
+  class ErrorWorker
+    include Sidekiq::Worker
+
+    def perform()
+      raise TestError, 'job error'
+    end
+  end
+
+  def setup
+    super
+
+    Sidekiq::Testing.server_middleware do |chain|
+        chain.add(Datadog::Contrib::Sidekiq::Tracer,
+                  tracer: @tracer, enabled: true)
+    end
+  end
+
+  def test_empty
+    EmptyWorker.perform_async()
+
+    spans = @writer.spans()
+    assert_equal(1, spans.length)
+
+    span = spans[0]
+    assert_equal('sidekiq', span.service)
+    assert_equal('TracerTest::EmptyWorker', span.resource)
+    assert_equal('default', span.get_tag('sidekiq.job.queue'))
+    assert_equal(0, span.status)
+    assert_nil(span.parent)
+  end
+
+  def test_error
+    begin
+      ErrorWorker.perform_async()
+    rescue TestError
+    end
+
+    spans = @writer.spans()
+    assert_equal(1, spans.length)
+
+    span = spans[0]
+    assert_equal('sidekiq', span.service)
+    assert_equal('TracerTest::ErrorWorker', span.resource)
+    assert_equal('default', span.get_tag('sidekiq.job.queue'))
+    assert_equal(1, span.status)
+    assert_equal('job error', span.get_tag(Datadog::Ext::Errors::MSG))
+    assert_equal('TracerTest::TestError', span.get_tag(Datadog::Ext::Errors::TYPE))
+    assert_nil(span.parent)
+  end
+end

test/contrib/sidekiq/tracer_test_base.rb

@@ -0,0 +1,27 @@
+
+require 'sidekiq/testing'
+require 'ddtrace'
+require 'ddtrace/contrib/sidekiq/tracer'
+require 'helper'
+
+class TracerTestBase < Minitest::Test
+  REDIS_HOST = '127.0.0.1'.freeze()
+  REDIS_PORT = 46379
+
+  def setup
+    @writer = FauxWriter.new()
+    @tracer = Datadog::Tracer.new(writer: @writer)
+
+    redis_url = "redis://#{REDIS_HOST}:#{REDIS_PORT}"
+
+    Sidekiq.configure_client do |config|
+      config.redis = { url: redis_url }
+    end
+
+    Sidekiq.configure_server do |config|
+      config.redis = { url: redis_url }
+    end
+
+    Sidekiq::Testing.inline!
+  end
+end