14 files changed, 462 insertions, 1 deletions

diff --git a/.rubocop.yml b/.rubocop.yml
index e8e550fdbde..bcff67ded8c 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -143,6 +143,7 @@ Naming/FileName:
     - XMPP
     - XSRF
     - XSS
+    - GRPC
 
 # GitLab ###################################################################
 
diff --git a/changelogs/unreleased/an-opentracing-propagation.yml b/changelogs/unreleased/an-opentracing-propagation.yml
new file mode 100644
index 00000000000..d9aa7cd0048
--- /dev/null
+++ b/changelogs/unreleased/an-opentracing-propagation.yml
@@ -0,0 +1,5 @@
+---
+title: Adds inter-service OpenTracing propagation
+merge_request: 24239
+author:
+type: other
diff --git a/config/initializers/tracing.rb b/config/initializers/tracing.rb
index be95f30d075..46e8125daf8 100644
--- a/config/initializers/tracing.rb
+++ b/config/initializers/tracing.rb
@@ -3,6 +3,26 @@
 if Gitlab::Tracing.enabled?
   require 'opentracing'
 
+  Rails.application.configure do |config|
+    config.middleware.insert_after Gitlab::Middleware::CorrelationId, ::Gitlab::Tracing::RackMiddleware
+  end
+
+  # Instrument the Sidekiq client
+  Sidekiq.configure_client do |config|
+    config.client_middleware do |chain|
+      chain.add Gitlab::Tracing::Sidekiq::ClientMiddleware
+    end
+  end
+
+  # Instrument Sidekiq server calls when running Sidekiq server
+  if Sidekiq.server?
+    Sidekiq.configure_server do |config|
+      config.server_middleware do |chain|
+        chain.add Gitlab::Tracing::Sidekiq::ServerMiddleware
+      end
+    end
+  end
+
   # In multi-processed clustered architectures (puma, unicorn) don't
   # start tracing until the worker processes are spawned. This works
   # around issues when the opentracing implementation spawns threads
diff --git a/lib/gitlab/gitaly_client.rb b/lib/gitlab/gitaly_client.rb
index 8bf8a3b53cd..85afbd85fe6 100644
--- a/lib/gitlab/gitaly_client.rb
+++ b/lib/gitlab/gitaly_client.rb
@@ -52,11 +52,18 @@ module Gitlab
           klass = stub_class(name)
           addr = stub_address(storage)
           creds = stub_creds(storage)
-          klass.new(addr, creds)
+          klass.new(addr, creds, interceptors: interceptors)
         end
       end
     end
 
+    def self.interceptors
+      return [] unless Gitlab::Tracing.enabled?
+
+      [Gitlab::Tracing::GRPCInterceptor.instance]
+    end
+    private_class_method :interceptors
+
     def self.stub_cert_paths
       cert_paths = Dir["#{OpenSSL::X509::DEFAULT_CERT_DIR}/*"]
       cert_paths << OpenSSL::X509::DEFAULT_CERT_FILE if File.exist? OpenSSL::X509::DEFAULT_CERT_FILE
diff --git a/lib/gitlab/tracing/common.rb b/lib/gitlab/tracing/common.rb
new file mode 100644
index 00000000000..5e2b12e3f90
--- /dev/null
+++ b/lib/gitlab/tracing/common.rb
@@ -0,0 +1,59 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Tracing
+    module Common
+      def tracer
+        OpenTracing.global_tracer
+      end
+
+      # Convience method for running a block with a span
+      def in_tracing_span(operation_name:, tags:, child_of: nil)
+        scope = tracer.start_active_span(
+          operation_name,
+          child_of: child_of,
+          tags: tags
+        )
+        span = scope.span
+
+        # Add correlation details to the span if we have them
+        correlation_id = Gitlab::CorrelationId.current_id
+        if correlation_id
+          span.set_tag('correlation_id', correlation_id)
+        end
+
+        begin
+          yield span
+        rescue => e
+          log_exception_on_span(span, e)
+          raise e
+        ensure
+          scope.close
+        end
+      end
+
+      def log_exception_on_span(span, exception)
+        span.set_tag('error', true)
+        span.log_kv(kv_tags_for_exception(exception))
+      end
+
+      def kv_tags_for_exception(exception)
+        case exception
+        when Exception
+          {
+            'event':      'error',
+            'error.kind': exception.class.to_s,
+            'message':    Gitlab::UrlSanitizer.sanitize(exception.message),
+            'stack':      exception.backtrace.join("\n")
+          }
+        else
+          {
+            'event':        'error',
+            'error.kind':   exception.class.to_s,
+            'error.object': Gitlab::UrlSanitizer.sanitize(exception.to_s)
+          }
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/tracing/grpc_interceptor.rb b/lib/gitlab/tracing/grpc_interceptor.rb
new file mode 100644
index 00000000000..6c2aab73125
--- /dev/null
+++ b/lib/gitlab/tracing/grpc_interceptor.rb
@@ -0,0 +1,54 @@
+# frozen_string_literal: true
+
+require 'opentracing'
+require 'grpc'
+
+module Gitlab
+  module Tracing
+    class GRPCInterceptor < GRPC::ClientInterceptor
+      include Common
+      include Singleton
+
+      def request_response(request:, call:, method:, metadata:)
+        wrap_with_tracing(method, 'unary', metadata) do
+          yield
+        end
+      end
+
+      def client_streamer(requests:, call:, method:, metadata:)
+        wrap_with_tracing(method, 'client_stream', metadata) do
+          yield
+        end
+      end
+
+      def server_streamer(request:, call:, method:, metadata:)
+        wrap_with_tracing(method, 'server_stream', metadata) do
+          yield
+        end
+      end
+
+      def bidi_streamer(requests:, call:, method:, metadata:)
+        wrap_with_tracing(method, 'bidi_stream', metadata) do
+          yield
+        end
+      end
+
+      private
+
+      def wrap_with_tracing(method, grpc_type, metadata)
+        tags = {
+          'component' =>  'grpc',
+          'span.kind' =>  'client',
+          'grpc.method' => method,
+          'grpc.type' =>   grpc_type
+        }
+
+        in_tracing_span(operation_name: "grpc:#{method}", tags: tags) do |span|
+          OpenTracing.inject(span.context, OpenTracing::FORMAT_TEXT_MAP, metadata)
+
+          yield
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/tracing/rack_middleware.rb b/lib/gitlab/tracing/rack_middleware.rb
new file mode 100644
index 00000000000..e6a31293f7b
--- /dev/null
+++ b/lib/gitlab/tracing/rack_middleware.rb
@@ -0,0 +1,46 @@
+# frozen_string_literal: true
+
+require 'opentracing'
+
+module Gitlab
+  module Tracing
+    class RackMiddleware
+      include Common
+
+      REQUEST_METHOD = 'REQUEST_METHOD'
+
+      def initialize(app)
+        @app = app
+      end
+
+      def call(env)
+        method = env[REQUEST_METHOD]
+
+        context = tracer.extract(OpenTracing::FORMAT_RACK, env)
+        tags = {
+          'component' =>   'rack',
+          'span.kind' =>   'server',
+          'http.method' => method,
+          'http.url' =>    self.class.build_sanitized_url_from_env(env)
+        }
+
+        in_tracing_span(operation_name: "http:#{method}", child_of: context, tags: tags) do |span|
+          @app.call(env).tap do |status_code, _headers, _body|
+            span.set_tag('http.status_code', status_code)
+          end
+        end
+      end
+
+      # Generate a sanitized (safe) request URL from the rack environment
+      def self.build_sanitized_url_from_env(env)
+        request = ActionDispatch::Request.new(env)
+
+        original_url = request.original_url
+        uri = URI.parse(original_url)
+        uri.query = request.filtered_parameters.to_query if uri.query.present?
+
+        uri.to_s
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/tracing/sidekiq/client_middleware.rb b/lib/gitlab/tracing/sidekiq/client_middleware.rb
new file mode 100644
index 00000000000..2b71c1ea21e
--- /dev/null
+++ b/lib/gitlab/tracing/sidekiq/client_middleware.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+require 'opentracing'
+
+module Gitlab
+  module Tracing
+    module Sidekiq
+      class ClientMiddleware
+        include SidekiqCommon
+
+        SPAN_KIND = 'client'
+
+        def call(worker_class, job, queue, redis_pool)
+          in_tracing_span(
+            operation_name: "sidekiq:#{job['class']}",
+            tags: tags_from_job(job, SPAN_KIND)) do |span|
+            # Inject the details directly into the job
+            tracer.inject(span.context, OpenTracing::FORMAT_TEXT_MAP, job)
+
+            yield
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/tracing/sidekiq/server_middleware.rb b/lib/gitlab/tracing/sidekiq/server_middleware.rb
new file mode 100644
index 00000000000..5b43c4310e6
--- /dev/null
+++ b/lib/gitlab/tracing/sidekiq/server_middleware.rb
@@ -0,0 +1,26 @@
+# frozen_string_literal: true
+
+require 'opentracing'
+
+module Gitlab
+  module Tracing
+    module Sidekiq
+      class ServerMiddleware
+        include SidekiqCommon
+
+        SPAN_KIND = 'server'
+
+        def call(worker, job, queue)
+          context = tracer.extract(OpenTracing::FORMAT_TEXT_MAP, job)
+
+          in_tracing_span(
+            operation_name: "sidekiq:#{job['class']}",
+            child_of: context,
+            tags: tags_from_job(job, SPAN_KIND)) do |span|
+            yield
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/tracing/sidekiq/sidekiq_common.rb b/lib/gitlab/tracing/sidekiq/sidekiq_common.rb
new file mode 100644
index 00000000000..a911a29d773
--- /dev/null
+++ b/lib/gitlab/tracing/sidekiq/sidekiq_common.rb
@@ -0,0 +1,22 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Tracing
+    module Sidekiq
+      module SidekiqCommon
+        include Gitlab::Tracing::Common
+
+        def tags_from_job(job, kind)
+          {
+            'component' =>     'sidekiq',
+            'span.kind' =>     kind,
+            'sidekiq.queue' => job['queue'],
+            'sidekiq.jid' =>   job['jid'],
+            'sidekiq.retry' => job['retry'].to_s,
+            'sidekiq.args' =>  job['args']&.join(", ")
+          }
+        end
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/tracing/grpc_interceptor_spec.rb b/spec/lib/gitlab/tracing/grpc_interceptor_spec.rb
new file mode 100644
index 00000000000..7f5aecb7baa
--- /dev/null
+++ b/spec/lib/gitlab/tracing/grpc_interceptor_spec.rb
@@ -0,0 +1,47 @@
+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+
+describe Gitlab::Tracing::GRPCInterceptor do
+  subject { described_class.instance }
+
+  shared_examples_for "a grpc interceptor method" do
+    let(:custom_error) { Class.new(StandardError) }
+
+    it 'yields' do
+      expect { |b| method.call(kwargs, &b) }.to yield_control
+    end
+
+    it 'propagates exceptions' do
+      expect { method.call(kwargs) { raise custom_error } }.to raise_error(custom_error)
+    end
+  end
+
+  describe '#request_response' do
+    let(:method) { subject.method(:request_response) }
+    let(:kwargs) { { request: {}, call: {}, method: 'grc_method', metadata: {} } }
+
+    it_behaves_like 'a grpc interceptor method'
+  end
+
+  describe '#client_streamer' do
+    let(:method) { subject.method(:client_streamer) }
+    let(:kwargs) { { requests: [], call: {}, method: 'grc_method', metadata: {} } }
+
+    it_behaves_like 'a grpc interceptor method'
+  end
+
+  describe '#server_streamer' do
+    let(:method) { subject.method(:server_streamer) }
+    let(:kwargs) { { request: {}, call: {}, method: 'grc_method', metadata: {} } }
+
+    it_behaves_like 'a grpc interceptor method'
+  end
+
+  describe '#bidi_streamer' do
+    let(:method) { subject.method(:bidi_streamer) }
+    let(:kwargs) { { requests: [], call: {}, method: 'grc_method', metadata: {} } }
+
+    it_behaves_like 'a grpc interceptor method'
+  end
+end
diff --git a/spec/lib/gitlab/tracing/rack_middleware_spec.rb b/spec/lib/gitlab/tracing/rack_middleware_spec.rb
new file mode 100644
index 00000000000..13d4d8a89f7
--- /dev/null
+++ b/spec/lib/gitlab/tracing/rack_middleware_spec.rb
@@ -0,0 +1,62 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Tracing::RackMiddleware do
+  using RSpec::Parameterized::TableSyntax
+
+  describe '#call' do
+    context 'for normal middleware flow' do
+      let(:fake_app) { -> (env) { fake_app_response } }
+      subject { described_class.new(fake_app) }
+      let(:request) {  }
+
+      context 'for 200 responses' do
+        let(:fake_app_response) { [200, { 'Content-Type': 'text/plain' }, ['OK']] }
+
+        it 'delegates correctly' do
+          expect(subject.call(Rack::MockRequest.env_for("/"))).to eq(fake_app_response)
+        end
+      end
+
+      context 'for 500 responses' do
+        let(:fake_app_response) { [500, { 'Content-Type': 'text/plain' }, ['Error']] }
+
+        it 'delegates correctly' do
+          expect(subject.call(Rack::MockRequest.env_for("/"))).to eq(fake_app_response)
+        end
+      end
+    end
+
+    context 'when an application is raising an exception' do
+      let(:custom_error) { Class.new(StandardError) }
+      let(:fake_app) { ->(env) { raise custom_error } }
+
+      subject { described_class.new(fake_app) }
+
+      it 'delegates propagates exceptions correctly' do
+        expect { subject.call(Rack::MockRequest.env_for("/")) }.to raise_error(custom_error)
+      end
+    end
+  end
+
+  describe '.build_sanitized_url_from_env' do
+    def env_for_url(url)
+      env = Rack::MockRequest.env_for(input_url)
+      env['action_dispatch.parameter_filter'] = [/token/]
+
+      env
+    end
+
+    where(:input_url, :output_url) do
+      '/gitlab-org/gitlab-ce'                              | 'http://example.org/gitlab-org/gitlab-ce'
+      '/gitlab-org/gitlab-ce?safe=1'                       | 'http://example.org/gitlab-org/gitlab-ce?safe=1'
+      '/gitlab-org/gitlab-ce?private_token=secret'         | 'http://example.org/gitlab-org/gitlab-ce?private_token=%5BFILTERED%5D'
+      '/gitlab-org/gitlab-ce?mixed=1&private_token=secret' | 'http://example.org/gitlab-org/gitlab-ce?mixed=1&private_token=%5BFILTERED%5D'
+    end
+
+    with_them do
+      it { expect(described_class.build_sanitized_url_from_env(env_for_url(input_url))).to eq(output_url) }
+    end
+  end
+end
diff --git a/spec/lib/gitlab/tracing/sidekiq/client_middleware_spec.rb b/spec/lib/gitlab/tracing/sidekiq/client_middleware_spec.rb
new file mode 100644
index 00000000000..3755860b5ba
--- /dev/null
+++ b/spec/lib/gitlab/tracing/sidekiq/client_middleware_spec.rb
@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+
+describe Gitlab::Tracing::Sidekiq::ClientMiddleware do
+  describe '#call' do
+    let(:worker_class) { 'test_worker_class' }
+    let(:job) do
+      {
+        'class' => "jobclass",
+        'queue' => "jobqueue",
+        'retry' => 0,
+        'args' =>  %w{1 2 3}
+      }
+    end
+    let(:queue) { 'test_queue' }
+    let(:redis_pool) { double("redis_pool") }
+    let(:custom_error) { Class.new(StandardError) }
+    let(:span) { OpenTracing.start_span('test', ignore_active_scope: true) }
+
+    subject { described_class.new }
+
+    it 'yields' do
+      expect(subject).to receive(:in_tracing_span).with(
+        operation_name: "sidekiq:jobclass",
+        tags: {
+          "component" =>     "sidekiq",
+          "span.kind" =>     "client",
+          "sidekiq.queue" => "jobqueue",
+          "sidekiq.jid" =>   nil,
+          "sidekiq.retry" => "0",
+          "sidekiq.args" =>  "1, 2, 3"
+        }
+      ).and_yield(span)
+
+      expect { |b| subject.call(worker_class, job, queue, redis_pool, &b) }.to yield_control
+    end
+
+    it 'propagates exceptions' do
+      expect { subject.call(worker_class, job, queue, redis_pool) { raise custom_error } }.to raise_error(custom_error)
+    end
+  end
+end
diff --git a/spec/lib/gitlab/tracing/sidekiq/server_middleware_spec.rb b/spec/lib/gitlab/tracing/sidekiq/server_middleware_spec.rb
new file mode 100644
index 00000000000..c3087de785a
--- /dev/null
+++ b/spec/lib/gitlab/tracing/sidekiq/server_middleware_spec.rb
@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+require 'fast_spec_helper'
+
+describe Gitlab::Tracing::Sidekiq::ServerMiddleware do
+  describe '#call' do
+    let(:worker_class) { 'test_worker_class' }
+    let(:job) do
+      {
+        'class' => "jobclass",
+        'queue' => "jobqueue",
+        'retry' => 0,
+        'args' =>  %w{1 2 3}
+      }
+    end
+    let(:queue) { 'test_queue' }
+    let(:custom_error) { Class.new(StandardError) }
+    let(:span) { OpenTracing.start_span('test', ignore_active_scope: true) }
+    subject { described_class.new }
+
+    it 'yields' do
+      expect(subject).to receive(:in_tracing_span).with(
+        hash_including(
+          operation_name: "sidekiq:jobclass",
+          tags: {
+            "component" =>     "sidekiq",
+            "span.kind" =>     "server",
+            "sidekiq.queue" => "jobqueue",
+            "sidekiq.jid" =>   nil,
+            "sidekiq.retry" => "0",
+            "sidekiq.args" =>  "1, 2, 3"
+          }
+        )
+      ).and_yield(span)
+
+      expect { |b| subject.call(worker_class, job, queue, &b) }.to yield_control
+    end
+
+    it 'propagates exceptions' do
+      expect { subject.call(worker_class, job, queue) { raise custom_error } }.to raise_error(custom_error)
+    end
+  end
+end