Use duration_s in GraphQL logs

We changed to add a suffix with the unit in our other logs files, but
missed this one.

doc/administration/logs.md

@@ -613,7 +613,7 @@ installations from source.
 GraphQL queries are recorded in that file. For example:
 
 ```json
-{"query_string":"query IntrospectionQuery{__schema {queryType { name },mutationType { name }}}...(etc)","variables":{"a":1,"b":2},"complexity":181,"depth":1,"duration":7}
+{"query_string":"query IntrospectionQuery{__schema {queryType { name },mutationType { name }}}...(etc)","variables":{"a":1,"b":2},"complexity":181,"depth":1,"duration_s":7}
 ```
 
 ## `migrations.log`

lib/gitlab/graphql/query_analyzers/logger_analyzer.rb

@@ -34,7 +34,7 @@ module Gitlab
 
           memo[:depth] = depth
           memo[:complexity] = complexity
-          memo[:duration] = duration(memo[:time_started]).round(1)
+          memo[:duration_s] = duration(memo[:time_started]).round(1)
 
           GraphqlLogger.info(memo.except!(:time_started, :query))
         rescue => e
@@ -62,7 +62,7 @@ module Gitlab
             query_string: nil,
             query: query,
             variables: nil,
-            duration: nil
+            duration_s: nil
           }
         end
       end

spec/lib/gitlab/graphql_logger_spec.rb

@@ -23,7 +23,7 @@ describe Gitlab::GraphqlLogger do
         variables: {},
         complexity: 181,
         depth: 0,
-        duration: 7
+        duration_s: 7
       }
 
       output = subject.format_message('INFO', now, 'test', analyzer_memo)
@@ -34,7 +34,7 @@ describe Gitlab::GraphqlLogger do
       expect(data['complexity']).to eq(181)
       expect(data['variables']).to eq({})
       expect(data['depth']).to eq(0)
-      expect(data['duration']).to eq(7)
+      expect(data['duration_s']).to eq(7)
     end
   end
 end

spec/requests/api/graphql/gitlab_schema_spec.rb

@@ -190,7 +190,7 @@ describe 'GitlabSchema configurations' do
         variables: {}.to_s,
         complexity: 181,
         depth: 13,
-        duration: 7
+        duration_s: 7
       }
 
       expect_any_instance_of(Gitlab::Graphql::QueryAnalyzers::LoggerAnalyzer).to receive(:duration).and_return(7)

spec/requests/api/graphql_spec.rb

@@ -9,7 +9,7 @@ describe 'GraphQL' do
   context 'logging' do
     shared_examples 'logging a graphql query' do
       let(:expected_params) do
-        { query_string: query, variables: variables.to_s, duration: anything, depth: 1, complexity: 1 }
+        { query_string: query, variables: variables.to_s, duration_s: anything, depth: 1, complexity: 1 }
       end
 
       it 'logs a query with the expected params' do