Make stuff work with older rails

sentry-rails/lib/sentry/rails/tracing/active_record_subscriber.rb

@@ -13,19 +13,31 @@ def self.subscribe!
             next if EXCLUDED_EVENTS.include? payload[:name]
 
             record_on_current_span(op: SPAN_PREFIX + event_name, start_timestamp: payload[START_TIMESTAMP_NAME], description: payload[:sql], duration: duration) do |span|
-              span.set_data(:connection_id, payload[:connection_id]) if payload[:connection_id]
               span.set_tag(:cached, true) if payload.fetch(:cached, false) # cached key is only set for hits in the QueryCache, from Rails 5.1
 
-              if payload[:connection]
-                db_config = payload[:connection].pool.db_config.configuration_hash
+              connection = payload[:connection]
 
-                span.set_data(Span::DataConventions::DB_NAME, db_config[:database])
-                span.set_data(Span::DataConventions::DB_SYSTEM, db_config[:adapter])
+              if payload[:connection_id]
+                span.set_data(:connection_id, payload[:connection_id])
 
-                span.set_data(Span::DataConventions::SERVER_ADDRESS, db_config[:host]) if db_config[:host]
-                span.set_data(Span::DataConventions::SERVER_PORT, db_config[:port]) if db_config[:port]
-                span.set_data(Span::DataConventions::SERVER_SOCKET_ADDRESS, db_config[:socket]) if db_config[:socket]
+                # we fallback to the base connection on rails < 6.0.0 since the payload doesn't have it
+                base_connection = ActiveRecord::Base.connection
+                connection ||= base_connection if payload[:connection_id] == base_connection.object_id
               end
+
+              next unless connection
+
+              db_config = if connection.pool.respond_to?(:db_config)
+                            connection.pool.db_config.configuration_hash
+                          elsif connection.pool.respond_to?(:spec)
+                            connection.pool.spec.config
+                          end
+
+              span.set_data(Span::DataConventions::DB_NAME, db_config[:database]) if db_config[:database]
+              span.set_data(Span::DataConventions::DB_SYSTEM, db_config[:adapter]) if db_config[:adapter]
+              span.set_data(Span::DataConventions::SERVER_ADDRESS, db_config[:host]) if db_config[:host]
+              span.set_data(Span::DataConventions::SERVER_PORT, db_config[:port]) if db_config[:port]
+              span.set_data(Span::DataConventions::SERVER_SOCKET_ADDRESS, db_config[:socket]) if db_config[:socket]
             end
           end
         end

sentry-rails/spec/sentry/rails/tracing/active_record_subscriber_spec.rb

@@ -34,7 +34,7 @@
       expect(span[:trace_id]).to eq(transaction.dig(:contexts, :trace, :trace_id))
 
       data = span[:data]
-      expect(data["db.name"]).to eq("db")
+      expect(data["db.name"]).to include("db")
       expect(data["db.system"]).to eq("sqlite3")
     end
 
@@ -61,7 +61,7 @@
       expect(cached_query_span[:tags]).to include({cached: true})
 
       data = cached_query_span[:data]
-      expect(data["db.name"]).to eq("db")
+      expect(data["db.name"]).to include("db")
       expect(data["db.system"]).to eq("sqlite3")
     end
   end