Log and pass correlation-id between Unicorn, Sidekiq and Gitaly

The Correlation ID is taken or generated from received X-Request-ID.
Then it is being passed to all executed services (sidekiq workers
or gitaly calls).

The Correlation ID is logged in all structured logs as `correlation_id`.

1 files changed, 38 insertions, 0 deletions

diff --git a/spec/initializers/lograge_spec.rb b/spec/initializers/lograge_spec.rb
new file mode 100644
index 00000000000..af54a777373
--- /dev/null
+++ b/spec/initializers/lograge_spec.rb
@@ -0,0 +1,38 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe 'lograge', type: :request do
+  let(:headers) { { 'X-Request-ID' => 'new-correlation-id' } }
+
+  context 'for API requests' do
+    subject { get("/api/v4/endpoint", {}, headers) }
+
+    it 'logs to api_json log' do
+      # we assert receiving parameters by grape logger
+      expect_any_instance_of(Gitlab::GrapeLogging::Formatters::LogrageWithTimestamp).to receive(:call)
+        .with(anything, anything, anything, a_hash_including("correlation_id" => "new-correlation-id"))
+        .and_call_original
+
+      subject
+    end
+  end
+
+  context 'for Controller requests' do
+    subject { get("/", {}, headers) }
+
+    it 'logs to production_json log' do
+      # formatter receives a hash with correlation id
+      expect(Lograge.formatter).to receive(:call)
+        .with(a_hash_including("correlation_id" => "new-correlation-id"))
+        .and_call_original
+
+      # a log file receives a line with correlation id
+      expect(Lograge.logger).to receive(:send)
+        .with(anything, include('"correlation_id":"new-correlation-id"'))
+        .and_call_original
+
+      subject
+    end
+  end
+end