feat(otlp): Add collector_url option to OTLP integration

Allow users with their own OpenTelemetry collector to pass a custom
collector URL via config.otlp.collector_url. When set, traces are sent
to the specified endpoint without Sentry auth headers. When not set,
the existing behavior of deriving the endpoint from the DSN is preserved.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: sl0thentr0py

sentry-opentelemetry/Gemfile

@@ -9,6 +9,7 @@ eval_gemfile "../Gemfile.dev"
 gemspec
 
 gem "opentelemetry-sdk"
+gem "opentelemetry-exporter-otlp"
 gem "opentelemetry-instrumentation-rails"
 
 gem "sentry-ruby", path: "../sentry-ruby"

sentry-opentelemetry/lib/sentry/opentelemetry/configuration.rb

@@ -21,11 +21,13 @@ module OTLP
     class Configuration
       attr_accessor :enabled
       attr_accessor :setup_otlp_traces_exporter
+      attr_accessor :collector_url
       attr_accessor :setup_propagator
 
       def initialize
         @enabled = false
         @setup_otlp_traces_exporter = true
+        @collector_url = nil
         @setup_propagator = true
       end
     end

sentry-opentelemetry/lib/sentry/opentelemetry/otlp_setup.rb

@@ -11,6 +11,7 @@ module OTLPSetup
       class << self
         def setup(config)
           @dsn = config.dsn
+          @collector_url = config.otlp.collector_url
           @sdk_logger = config.sdk_logger
           log_debug("[OTLP] Setting up OTLP integration")
 
@@ -39,7 +40,7 @@ def setup_external_propagation_context
         end
 
         def setup_otlp_exporter
-          return unless @dsn
+          return unless @dsn || @collector_url
 
           log_debug("[OTLP] Setting up OTLP exporter")
 
@@ -51,15 +52,20 @@ def setup_otlp_exporter
             return
           end
 
-          endpoint = "#{@dsn.server}#{@dsn.otlp_traces_endpoint}"
-          auth_header = @dsn.generate_auth_header(client: USER_AGENT)
+          exporter = if @collector_url
+            endpoint = @collector_url
+            headers = {}
+            log_debug("[OTLP] Sending traces to collector at #{endpoint}")
 
-          log_debug("[OTLP] Sending traces to #{endpoint}")
+            ::OpenTelemetry::Exporter::OTLP::Exporter.new(endpoint: endpoint)
+          else
+            endpoint = "#{@dsn.server}#{@dsn.otlp_traces_endpoint}"
+            auth_header = @dsn.generate_auth_header(client: USER_AGENT)
+            headers = { "X-Sentry-Auth" => auth_header }
+            log_debug("[OTLP] Sending traces to #{endpoint}")
 
-          exporter = ::OpenTelemetry::Exporter::OTLP::Exporter.new(
-            endpoint: endpoint,
-            headers: { "X-Sentry-Auth" => auth_header }
-          )
+            ::OpenTelemetry::Exporter::OTLP::Exporter.new(endpoint: endpoint, headers: headers)
+          end
 
           span_processor = ::OpenTelemetry::SDK::Trace::Export::BatchSpanProcessor.new(exporter)
           ::OpenTelemetry.tracer_provider.add_span_processor(span_processor)

sentry-opentelemetry/spec/sentry/opentelemetry/configuration_spec.rb

@@ -7,6 +7,7 @@
     it "sets default values" do
       expect(subject.enabled).to eq(false)
       expect(subject.setup_otlp_traces_exporter).to eq(true)
+      expect(subject.collector_url).to be_nil
       expect(subject.setup_propagator).to eq(true)
     end
   end
@@ -17,6 +18,11 @@
       expect(subject.enabled).to eq(true)
     end
 
+    it "allows setting collector_url" do
+      subject.collector_url = "http://localhost:4318/v1/traces"
+      expect(subject.collector_url).to eq("http://localhost:4318/v1/traces")
+    end
+
     it "allows setting setup_otlp_traces_exporter" do
       subject.setup_otlp_traces_exporter = false
       expect(subject.setup_otlp_traces_exporter).to eq(false)

sentry-opentelemetry/spec/sentry/opentelemetry/otlp_setup_spec.rb

@@ -7,6 +7,10 @@
     perform_otel_setup
   end
 
+  def span_processors
+    ::OpenTelemetry.tracer_provider.instance_variable_get(:@span_processors)
+  end
+
   describe '.setup' do
     context 'with setup_propagator enabled' do
       before do
@@ -24,20 +28,79 @@
     end
 
     context 'with setup_otlp_traces_exporter enabled' do
-      before do
-        perform_basic_setup do |config|
-          config.otlp.enabled = true
+      context 'without collector_url (default DSN-based endpoint)' do
+        before do
+          perform_basic_setup do |config|
+            config.otlp.enabled = true
+            config.otlp.setup_otlp_traces_exporter = true
+          end
+        end
+
+        it 'creates the exporter with the DSN endpoint and auth headers' do
+          dsn = Sentry.configuration.dsn
+          expected_endpoint = "#{dsn.server}#{dsn.otlp_traces_endpoint}"
+
+          expect(::OpenTelemetry::Exporter::OTLP::Exporter).to receive(:new)
+            .with(endpoint: expected_endpoint, headers: hash_including("X-Sentry-Auth"))
+            .and_call_original
+
+          described_class.setup(Sentry.configuration)
+
+          expect(span_processors.last).to be_a(::OpenTelemetry::SDK::Trace::Export::BatchSpanProcessor)
+        end
+      end
+
+      context 'with collector_url' do
+        let(:collector_url) { "http://localhost:4318/v1/traces" }
+
+        before do
+          perform_basic_setup do |config|
+            config.otlp.enabled = true
+            config.otlp.setup_otlp_traces_exporter = true
+            config.otlp.collector_url = collector_url
+          end
+        end
+
+        it 'creates the exporter with the collector endpoint' do
+          expect(::OpenTelemetry::Exporter::OTLP::Exporter).to receive(:new)
+            .with(endpoint: collector_url)
+            .and_call_original
+
+          described_class.setup(Sentry.configuration)
+
+          expect(span_processors.last).to be_a(::OpenTelemetry::SDK::Trace::Export::BatchSpanProcessor)
         end
       end
 
       it 'logs a warning when opentelemetry-exporter-otlp is not installed' do
+        perform_basic_setup do |config|
+          config.otlp.enabled = true
+          config.otlp.setup_otlp_traces_exporter = true
+        end
+
         allow_any_instance_of(Object).to receive(:require).with("opentelemetry/exporter/otlp").and_raise(LoadError)
 
         expect(Sentry.configuration.sdk_logger).to receive(:warn).with(/opentelemetry-exporter-otlp gem is not installed/)
         described_class.setup(Sentry.configuration)
       end
     end
 
+    context 'with setup_otlp_traces_exporter disabled' do
+      before do
+        perform_basic_setup do |config|
+          config.otlp.enabled = true
+          config.otlp.setup_otlp_traces_exporter = false
+        end
+      end
+
+      it 'does not add a span processor' do
+        processors_before = span_processors.length
+        described_class.setup(Sentry.configuration)
+
+        expect(span_processors.length).to eq(processors_before)
+      end
+    end
+
     context 'with external propagation context' do
       before do
         perform_basic_setup do |config|