Merge branch '59587-add-graphql-logging' into 'master'

Add logging to GraphQL

Closes #59587

See merge request gitlab-org/gitlab-ce!27885

4 files changed, 138 insertions, 0 deletions

diff --git a/spec/lib/gitlab/graphql/query_analyzers/logger_analyzer_spec.rb b/spec/lib/gitlab/graphql/query_analyzers/logger_analyzer_spec.rb
new file mode 100644
index 00000000000..66033736e01
--- /dev/null
+++ b/spec/lib/gitlab/graphql/query_analyzers/logger_analyzer_spec.rb
@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::Graphql::QueryAnalyzers::LoggerAnalyzer do
+  subject { described_class.new }
+
+  describe '#analyze?' do
+    context 'feature flag disabled' do
+      before do
+        stub_feature_flags(graphql_logging: false)
+      end
+
+      it 'disables the analyzer' do
+        expect(subject.analyze?(anything)).to be_falsey
+      end
+    end
+
+    context 'feature flag enabled by default' do
+      it 'enables the analyzer' do
+        expect(subject.analyze?(anything)).to be_truthy
+      end
+    end
+  end
+end
diff --git a/spec/lib/gitlab/graphql_logger_spec.rb b/spec/lib/gitlab/graphql_logger_spec.rb
new file mode 100644
index 00000000000..4977f98b83e
--- /dev/null
+++ b/spec/lib/gitlab/graphql_logger_spec.rb
@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Gitlab::GraphqlLogger do
+  subject { described_class.new('/dev/null') }
+
+  let(:now) { Time.now }
+
+  it 'builds a logger once' do
+    expect(::Logger).to receive(:new).and_call_original
+
+    subject.info('hello world')
+    subject.error('hello again')
+  end
+
+  context 'logging a GraphQL query' do
+    let(:query) { File.read(Rails.root.join('spec/fixtures/api/graphql/introspection.graphql')) }
+
+    it 'logs a query from JSON' do
+      analyzer_memo = {
+        query_string: query,
+        variables: {},
+        complexity: 181,
+        depth: 0,
+        duration: 7
+      }
+
+      output = subject.format_message('INFO', now, 'test', analyzer_memo)
+
+      data = JSON.parse(output)
+      expect(data['severity']).to eq('INFO')
+      expect(data['time']).to eq(now.utc.iso8601(3))
+      expect(data['complexity']).to eq(181)
+      expect(data['variables']).to eq({})
+      expect(data['depth']).to eq(0)
+      expect(data['duration']).to eq(7)
+    end
+  end
+end
diff --git a/spec/requests/api/graphql/gitlab_schema_spec.rb b/spec/requests/api/graphql/gitlab_schema_spec.rb
index 9beea2e2594..b6ca9246399 100644
--- a/spec/requests/api/graphql/gitlab_schema_spec.rb
+++ b/spec/requests/api/graphql/gitlab_schema_spec.rb
@@ -111,4 +111,29 @@ describe 'GitlabSchema configurations' do
       expect(graphql_errors).to be_nil
     end
   end
+
+  context 'logging' do
+    let(:query) { File.read(Rails.root.join('spec/fixtures/api/graphql/introspection.graphql')) }
+
+    it 'logs the query complexity and depth' do
+      analyzer_memo = {
+        query_string: query,
+        variables: {}.to_s,
+        complexity: 181,
+        depth: 0,
+        duration: 7
+      }
+
+      expect_any_instance_of(Gitlab::Graphql::QueryAnalyzers::LoggerAnalyzer).to receive(:duration).and_return(7)
+      expect(Gitlab::GraphqlLogger).to receive(:info).with(analyzer_memo)
+
+      post_graphql(query, current_user: nil)
+    end
+
+    it 'logs using `format_message`' do
+      expect_any_instance_of(Gitlab::GraphqlLogger).to receive(:format_message)
+
+      post_graphql(query, current_user: nil)
+    end
+  end
 end
diff --git a/spec/requests/api/graphql_spec.rb b/spec/requests/api/graphql_spec.rb
index cca87c16f27..656d6f8b50b 100644
--- a/spec/requests/api/graphql_spec.rb
+++ b/spec/requests/api/graphql_spec.rb
@@ -16,6 +16,54 @@ describe 'GraphQL' do
     end
   end
 
+  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 }
+      end
+
+      it 'logs a query with the expected params' do
+        expect(Gitlab::GraphqlLogger).to receive(:info).with(expected_params).once
+
+        post_graphql(query, variables: variables)
+      end
+
+      it 'does not instantiate any query analyzers' do # they are static and re-used
+        expect(GraphQL::Analysis::QueryComplexity).not_to receive(:new)
+        expect(GraphQL::Analysis::QueryDepth).not_to receive(:new)
+
+        2.times { post_graphql(query, variables: variables) }
+      end
+    end
+
+    context 'with no variables' do
+      let(:variables) { {} }
+
+      it_behaves_like 'logging a graphql query'
+    end
+
+    context 'with variables' do
+      let(:variables) do
+        { "foo" => "bar" }
+      end
+
+      it_behaves_like 'logging a graphql query'
+    end
+
+    context 'when there is an error in the logger' do
+      before do
+        allow_any_instance_of(Gitlab::Graphql::QueryAnalyzers::LoggerAnalyzer).to receive(:process_variables).and_raise(StandardError.new("oh noes!"))
+      end
+
+      it 'logs the exception in Sentry and continues with the request' do
+        expect(Gitlab::Sentry).to receive(:track_exception).at_least(1).times
+        expect(Gitlab::GraphqlLogger).to receive(:info)
+
+        post_graphql(query, variables: {})
+      end
+    end
+  end
+
   context 'invalid variables' do
     it 'returns an error' do
       post_graphql(query, variables: "This is not JSON")