Merge pull request #128 from FundingCircle/open-telemetry

Add open telemetry fields to messages by default if present

CHANGELOG.md

@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
+## [2.8.0] - 2023-11-14
+### Added
+- Support open-telemetry and add trace_id and span_id to logs events
+
 ## [2.7.0] - 2023-03-28
 ### Added
 - Support for sidekiq 7

lib/loga/formatters/gelf_formatter.rb

@@ -39,12 +39,7 @@ def call(severity, time, _progname, message)
       private
 
       def build_event(time, message)
-        event = case message
-                when Loga::Event
-                  message
-                else
-                  Loga::Event.new(message: message)
-                end
+        event = message.is_a?(Loga::Event) ? message : Loga::Event.new(message: message)
 
         event.timestamp ||= time
         # Overwrite sidekiq_context data anything manually specified
@@ -54,6 +49,7 @@ def build_event(time, message)
           hash.merge! compute_type(event.type)
           # Overwrite hash with Loga's additional fields
           hash.merge! loga_additional_fields
+          hash.merge! open_telemetry_fields
         end
         event
       end
@@ -103,6 +99,17 @@ def loga_additional_fields
         }
       end
 
+      def open_telemetry_fields
+        return {} unless defined?(::OpenTelemetry::Trace)
+
+        span = ::OpenTelemetry::Trace.current_span
+
+        {
+          trace_id: span.context.hex_trace_id,
+          span_id: span.context.hex_span_id,
+        }
+      end
+
       def sidekiq_context
         return {} unless defined?(::Sidekiq::Context)
 

lib/loga/version.rb

@@ -1,3 +1,3 @@
 module Loga
-  VERSION = '2.7.0'.freeze
+  VERSION = '2.8.0'.freeze
 end

spec/unit/loga/formatters/gelf_formatter_spec.rb

@@ -209,6 +209,29 @@ class << self
       end
     end
 
+    context 'when working with additional fields via otel' do
+      let(:options) { { message: 'Wooden house' } }
+      let(:message) { Loga::Event.new(options) }
+      let(:trace_context) { { hex_trace_id: '123', hex_span_id: '456' } }
+
+      before do
+        klass = Class.new do
+          class << self
+            attr_accessor :current_span
+          end
+        end
+        klass.current_span = OpenStruct.new(context: OpenStruct.new(trace_context))
+        stub_const('::OpenTelemetry::Trace', klass)
+      end
+
+      it 'includes the trace_id and span_id' do
+        expect(json['_trace_id']).to eq('123')
+        expect(json['_span_id']).to eq('456')
+      end
+
+      include_examples 'valid GELF message'
+    end
+
     {
       'DEBUG'   => 7,
       'INFO'    => 6,