Make retry an integer in Sidekiq logs

https://github.com/mperham/sidekiq/wiki/Error-Handling#configuration
says that `retry: false` is not exactly equivalent to `retry: 0` - it's
more like `retry: 0, dead: false`.

For logging, those cases are basically the same, though, and making this
always an integer prevents mapping errors.

lib/gitlab/sidekiq_logging/json_formatter.rb

@@ -19,6 +19,7 @@ module Gitlab
           output[:message] = data
         when Hash
           convert_to_iso8601!(data)
+          convert_retry_to_integer!(data)
           stringify_args!(data)
           output.merge!(data)
         end
@@ -41,6 +42,20 @@ module Gitlab
         Time.at(timestamp).utc.iso8601(3)
       end
 
+      def convert_retry_to_integer!(payload)
+        payload['retry'] =
+          case payload['retry']
+          when Integer
+            payload['retry']
+          when false, nil
+            0
+          when true
+            Sidekiq::JobRetry::DEFAULT_MAX_RETRY_ATTEMPTS
+          else
+            -1
+          end
+      end
+
       def stringify_args!(payload)
         payload['args'] = Gitlab::Utils::LogLimitedArray.log_limited_array(payload['args'].map(&:to_s)) if payload['args']
       end

spec/lib/gitlab/sidekiq_logging/json_formatter_spec.rb

@@ -34,7 +34,8 @@ describe Gitlab::SidekiqLogging::JSONFormatter do
           'started_at' => timestamp_iso8601,
           'retried_at' => timestamp_iso8601,
           'failed_at' => timestamp_iso8601,
-          'completed_at' => timestamp_iso8601
+          'completed_at' => timestamp_iso8601,
+          'retry' => 0
         }
       )
 
@@ -57,6 +58,26 @@ describe Gitlab::SidekiqLogging::JSONFormatter do
 
       expect(subject['args']).to eq(["1", "test", "2", %({"test"=>1})])
     end
+
+    context 'when the job has a non-integer value for retry' do
+      using RSpec::Parameterized::TableSyntax
+
+      where(:retry_in_job, :retry_in_logs) do
+        3        | 3
+        true     | 25
+        false    | 0
+        nil      | 0
+        'string' | -1
+      end
+
+      with_them do
+        it 'logs as the correct integer' do
+          hash_input['retry'] = retry_in_job
+
+          expect(subject['retry']).to eq(retry_in_logs)
+        end
+      end
+    end
   end
 
   describe 'with a String' do