Connect Sidekiq's transaction with its parent when possible (#1590)

* Connect Sidekiq's transaction with the previous one

If there's a parent transaction on the client side, its sentry_trace
should be passed and picked by the server side middleware, so the 2
transactions can connect.

* Update changelog

CHANGELOG.md

@@ -25,6 +25,11 @@
 - Start Testing Against Rails 7.0 [#1581](https://github.com/getsentry/sentry-ruby/pull/1581)
 - Tracing subscribers should be multi-event based [#1587](https://github.com/getsentry/sentry-ruby/pull/1587)
 
+### Bug Fixes
+
+- Connect `Sidekiq`'s transaction with its parent when possible [#1590](https://github.com/getsentry/sentry-ruby/pull/1590)
+  - Fixes [#1586](https://github.com/getsentry/sentry-ruby/issues/1586)
+
 ## 4.7.3
 
 - Avoid leaking tracing timestamp to breadcrumbs [#1575](https://github.com/getsentry/sentry-ruby/pull/1575)

sentry-sidekiq/lib/sentry/sidekiq/sentry_context_middleware.rb

@@ -16,12 +16,12 @@ def call(_worker, job, queue)
         scope.set_tags(queue: queue, jid: job["jid"])
         scope.set_contexts(sidekiq: job.merge("queue" => queue))
         scope.set_transaction_name(context_filter.transaction_name)
-        transaction = Sentry.start_transaction(name: scope.transaction_name, op: "sidekiq")
+        transaction = start_transaction(scope.transaction_name, job["sentry_trace"])
         scope.set_span(transaction) if transaction
 
         begin
           yield
-        rescue => e
+        rescue
           finish_transaction(transaction, 500)
           raise
         end
@@ -32,6 +32,12 @@ def call(_worker, job, queue)
         scope.clear
       end
 
+      def start_transaction(transaction_name, sentry_trace)
+        options = { name: transaction_name, op: "sidekiq" }
+        transaction = Sentry::Transaction.from_sentry_trace(sentry_trace, **options) if sentry_trace
+        Sentry.start_transaction(transaction: transaction, **options)
+      end
+
       def finish_transaction(transaction, status)
         return unless transaction
 
@@ -45,7 +51,9 @@ def call(_worker_class, job, _queue, _redis_pool)
         return yield unless Sentry.initialized?
 
         user = Sentry.get_current_scope.user
+        transaction = Sentry.get_current_scope.get_transaction
         job["sentry_user"] = user unless user.empty?
+        job["sentry_trace"] = transaction.to_sentry_trace if transaction
         yield
       end
     end

sentry-sidekiq/spec/sentry/sidekiq/sentry_context_middleware_spec.rb

@@ -51,6 +51,19 @@
       event = transport.events.last
       expect(event.user).to eq(user)
     end
+
+    context "with sentry_trace" do
+      let(:parent_transaction) { Sentry.start_transaction(op: "sidekiq") }
+
+      it "starts the transaction from it" do
+        execute_worker(processor, HappyWorker, sentry_trace: parent_transaction.to_sentry_trace)
+
+        expect(transport.events.count).to eq(1)
+        transaction = transport.events.first
+        expect(transaction).not_to be_nil
+        expect(transaction.contexts.dig(:trace, :trace_id)).to eq(parent_transaction.trace_id)
+      end
+    end
   end
 end
 
@@ -70,22 +83,44 @@
 
   before do
     queue.clear
-    perform_basic_setup
+    perform_basic_setup do |config|
+      config.traces_sample_rate = 1.0
+    end
   end
 
-  it "does not add user to the job if user is absence in the current scope" do
+  it "does not add user or sentry_trace to the job if they're absence in the current scope" do
     client.push('queue' => 'default', 'class' => HappyWorker, 'args' => [])
 
     expect(queue.size).to be(1)
     expect(queue.first["sentry_user"]).to be_nil
+    expect(queue.first["sentry_trace"]).to be_nil
   end
 
-  it "sets user of the current scope to the job if present" do
-    Sentry.set_user(user)
+  describe "with user" do
+    before do
+      Sentry.set_user(user)
+    end
 
-    client.push('queue' => 'default', 'class' => HappyWorker, 'args' => [])
+    it "sets user of the current scope to the job" do
+      client.push('queue' => 'default', 'class' => HappyWorker, 'args' => [])
 
-    expect(queue.size).to be(1)
-    expect(queue.first["sentry_user"]).to eq(user)
+      expect(queue.size).to be(1)
+      expect(queue.first["sentry_user"]).to eq(user)
+    end
+  end
+
+  describe "with transaction" do
+    let(:transaction) { Sentry.start_transaction(op: "sidekiq") }
+
+    before do
+      Sentry.get_current_scope.set_span(transaction)
+    end
+
+    it "sets user of the current scope to the job" do
+      client.push('queue' => 'default', 'class' => HappyWorker, 'args' => [])
+
+      expect(queue.size).to be(1)
+      expect(queue.first["sentry_trace"]).to eq(transaction.to_sentry_trace)
+    end
   end
 end

sentry-sidekiq/spec/spec_helper.rb

@@ -153,9 +153,8 @@ def perform
   end
 end
 
-def execute_worker(processor, klass)
+def execute_worker(processor, klass, **options)
   klass_options = klass.sidekiq_options_hash || {}
-  options = {}
 
   # for Ruby < 2.6
   klass_options.each do |k, v|