Merge branch '58409-increase-graphql-complexity-for-fields-that-make-gitaly-calls' into 'master'

Increase GraphQL complexity for fields that make Gitaly Calls

Closes #58409

See merge request gitlab-org/gitlab-ce!28814

app/graphql/gitlab_schema.rb

@@ -13,6 +13,7 @@ class GitlabSchema < GraphQL::Schema
   use BatchLoader::GraphQL
   use Gitlab::Graphql::Authorize
   use Gitlab::Graphql::Present
+  use Gitlab::Graphql::CallsGitaly
   use Gitlab::Graphql::Connections
   use Gitlab::Graphql::GenericTracing
 

app/graphql/types/base_field.rb

@@ -7,18 +7,34 @@ module Types
     DEFAULT_COMPLEXITY = 1
 
     def initialize(*args, **kwargs, &block)
+      @calls_gitaly = !!kwargs.delete(:calls_gitaly)
+      @constant_complexity = !!kwargs[:complexity]
       kwargs[:complexity] ||= field_complexity(kwargs[:resolver_class])
 
       super(*args, **kwargs, &block)
     end
 
+    def base_complexity
+      complexity = DEFAULT_COMPLEXITY
+      complexity += 1 if calls_gitaly?
+      complexity
+    end
+
+    def calls_gitaly?
+      @calls_gitaly
+    end
+
+    def constant_complexity?
+      @constant_complexity
+    end
+
     private
 
     def field_complexity(resolver_class)
       if resolver_class
         field_resolver_complexity
       else
-        DEFAULT_COMPLEXITY
+        base_complexity
       end
     end
 
@@ -31,6 +47,7 @@ module Types
       proc do |ctx, args, child_complexity|
         # Resolvers may add extra complexity depending on used arguments
         complexity = child_complexity + self.resolver&.try(:resolver_complexity, args, child_complexity: child_complexity).to_i
+        complexity += 1 if calls_gitaly?
 
         field_defn = to_graphql
 

app/graphql/types/merge_request_type.rb

@@ -43,7 +43,7 @@ module Types
     field :allow_collaboration, GraphQL::BOOLEAN_TYPE, null: true
     field :should_be_rebased, GraphQL::BOOLEAN_TYPE, method: :should_be_rebased?, null: false
     field :rebase_commit_sha, GraphQL::STRING_TYPE, null: true
-    field :rebase_in_progress, GraphQL::BOOLEAN_TYPE, method: :rebase_in_progress?, null: false
+    field :rebase_in_progress, GraphQL::BOOLEAN_TYPE, method: :rebase_in_progress?, null: false, calls_gitaly: true
     field :merge_commit_message, GraphQL::STRING_TYPE, method: :default_merge_commit_message, null: true, deprecation_reason: "Renamed to defaultMergeCommitMessage"
     field :default_merge_commit_message, GraphQL::STRING_TYPE, null: true
     field :merge_ongoing, GraphQL::BOOLEAN_TYPE, method: :merge_ongoing?, null: false

app/graphql/types/mutation_type.rb

@@ -9,6 +9,6 @@ module Types
     mount_mutation Mutations::AwardEmojis::Add
     mount_mutation Mutations::AwardEmojis::Remove
     mount_mutation Mutations::AwardEmojis::Toggle
-    mount_mutation Mutations::MergeRequests::SetWip
+    mount_mutation Mutations::MergeRequests::SetWip, calls_gitaly: true
   end
 end

app/graphql/types/permission_types/merge_request.rb

@@ -10,8 +10,8 @@ module Types
       abilities :read_merge_request, :admin_merge_request,
                 :update_merge_request, :create_note
 
-      permission_field :push_to_source_branch, method: :can_push_to_source_branch?
-      permission_field :remove_source_branch, method: :can_remove_source_branch?
+      permission_field :push_to_source_branch, method: :can_push_to_source_branch?, calls_gitaly: true
+      permission_field :remove_source_branch, method: :can_remove_source_branch?, calls_gitaly: true
       permission_field :cherry_pick_on_current_merge_request, method: :can_cherry_pick_on_current_merge_request?
       permission_field :revert_on_current_merge_request, method: :can_revert_on_current_merge_request?
     end

app/graphql/types/project_type.rb

@@ -26,7 +26,7 @@ module Types
     field :web_url, GraphQL::STRING_TYPE, null: true
 
     field :star_count, GraphQL::INT_TYPE, null: false
-    field :forks_count, GraphQL::INT_TYPE, null: false
+    field :forks_count, GraphQL::INT_TYPE, null: false, calls_gitaly: true # 4 times
 
     field :created_at, Types::TimeType, null: true
     field :last_activity_at, Types::TimeType, null: true
@@ -40,7 +40,7 @@ module Types
     field :lfs_enabled, GraphQL::BOOLEAN_TYPE, null: true
     field :merge_requests_ff_only_enabled, GraphQL::BOOLEAN_TYPE, null: true
 
-    field :avatar_url, GraphQL::STRING_TYPE, null: true, resolve: -> (project, args, ctx) do
+    field :avatar_url, GraphQL::STRING_TYPE, null: true, calls_gitaly: true, resolve: -> (project, args, ctx) do
       project.avatar_url(only_path: false)
     end
 

app/graphql/types/repository_type.rb

@@ -6,9 +6,9 @@ module Types
 
     authorize :download_code
 
-    field :root_ref, GraphQL::STRING_TYPE, null: true
-    field :empty, GraphQL::BOOLEAN_TYPE, null: false, method: :empty?
+    field :root_ref, GraphQL::STRING_TYPE, null: true, calls_gitaly: true
+    field :empty, GraphQL::BOOLEAN_TYPE, null: false, method: :empty?, calls_gitaly: true
     field :exists, GraphQL::BOOLEAN_TYPE, null: false, method: :exists?
-    field :tree, Types::Tree::TreeType, null: true, resolver: Resolvers::TreeResolver
+    field :tree, Types::Tree::TreeType, null: true, resolver: Resolvers::TreeResolver, calls_gitaly: true
   end
 end

app/graphql/types/tree/tree_type.rb

@@ -7,7 +7,7 @@ module Types
       graphql_name 'Tree'
 
       # Complexity 10 as it triggers a Gitaly call on each render
-      field :last_commit, Types::CommitType, null: true, complexity: 10, resolve: -> (tree, args, ctx) do
+      field :last_commit, Types::CommitType, null: true, complexity: 10, calls_gitaly: true, resolve: -> (tree, args, ctx) do
         tree.repository.last_commit_for_path(tree.sha, tree.path)
       end
 
@@ -15,9 +15,9 @@ module Types
         Gitlab::Graphql::Representation::TreeEntry.decorate(obj.trees, obj.repository)
       end
 
-      field :submodules, Types::Tree::SubmoduleType.connection_type, null: false
+      field :submodules, Types::Tree::SubmoduleType.connection_type, null: false, calls_gitaly: true
 
-      field :blobs, Types::Tree::BlobType.connection_type, null: false, resolve: -> (obj, args, ctx) do
+      field :blobs, Types::Tree::BlobType.connection_type, null: false, calls_gitaly: true, resolve: -> (obj, args, ctx) do
         Gitlab::Graphql::Representation::TreeEntry.decorate(obj.blobs, obj.repository)
       end
       # rubocop: enable Graphql/AuthorizeTypes

lib/gitlab/graphql/authorize.rb

@@ -8,7 +8,7 @@ module Gitlab
       extend ActiveSupport::Concern
 
       def self.use(schema_definition)
-        schema_definition.instrument(:field, Instrumentation.new, after_built_ins: true)
+        schema_definition.instrument(:field, Gitlab::Graphql::Authorize::Instrumentation.new, after_built_ins: true)
       end
     end
   end

lib/gitlab/graphql/calls_gitaly.rb

@@ -0,0 +1,15 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Graphql
+    # Wraps the field resolution to count Gitaly calls before and after.
+    # Raises an error if the field calls Gitaly but hadn't declared such.
+    module CallsGitaly
+      extend ActiveSupport::Concern
+
+      def self.use(schema_definition)
+        schema_definition.instrument(:field, Gitlab::Graphql::CallsGitaly::Instrumentation.new, after_built_ins: true)
+      end
+    end
+  end
+end

lib/gitlab/graphql/calls_gitaly/instrumentation.rb

@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+
+module Gitlab
+  module Graphql
+    module CallsGitaly
+      class Instrumentation
+        # Check if any `calls_gitaly: true` declarations need to be added
+        # Do nothing if a constant complexity was provided
+        def instrument(_type, field)
+          type_object = field.metadata[:type_class]
+          return field unless type_object.respond_to?(:calls_gitaly?)
+          return field if type_object.constant_complexity? || type_object.calls_gitaly?
+
+          old_resolver_proc = field.resolve_proc
+
+          gitaly_wrapped_resolve = -> (typed_object, args, ctx) do
+            previous_gitaly_call_count = Gitlab::GitalyClient.get_request_count
+            result = old_resolver_proc.call(typed_object, args, ctx)
+            current_gitaly_call_count = Gitlab::GitalyClient.get_request_count
+            calls_gitaly_check(type_object, current_gitaly_call_count - previous_gitaly_call_count)
+            result
+          end
+
+          field.redefine do
+            resolve(gitaly_wrapped_resolve)
+          end
+        end
+
+        def calls_gitaly_check(type_object, calls)
+          return if calls < 1
+
+          # Will inform you if there needs to be `calls_gitaly: true` as a kwarg in the field declaration
+          # if there is at least 1 Gitaly call involved with the field resolution.
+          error = RuntimeError.new("Gitaly is called for field '#{type_object.name}' on #{type_object.owner.try(:name)} - please either specify a constant complexity or add `calls_gitaly: true` to the field declaration")
+          Gitlab::Sentry.track_exception(error)
+        end
+      end
+    end
+  end
+end

lib/gitlab/graphql/mount_mutation.rb

@@ -6,11 +6,12 @@ module Gitlab
       extend ActiveSupport::Concern
 
       class_methods do
-        def mount_mutation(mutation_class)
+        def mount_mutation(mutation_class, **custom_kwargs)
           # Using an underscored field name symbol will make `graphql-ruby`
           # standardize the field name
           field mutation_class.graphql_name.underscore.to_sym,
-                mutation: mutation_class
+                mutation: mutation_class,
+                **custom_kwargs
         end
       end
     end

spec/graphql/gitlab_schema_spec.rb

@@ -21,6 +21,10 @@ describe GitlabSchema do
     expect(field_instrumenters).to include(instance_of(::Gitlab::Graphql::Present::Instrumentation))
   end
 
+  it 'enables using gitaly call checker' do
+    expect(field_instrumenters).to include(instance_of(::Gitlab::Graphql::CallsGitaly::Instrumentation))
+  end
+
   it 'has the base mutation' do
     expect(described_class.mutation).to eq(::Types::MutationType.to_graphql)
   end

spec/graphql/types/base_field_spec.rb

@@ -22,6 +22,24 @@ describe Types::BaseField do
       expect(field.to_graphql.complexity).to eq 1
     end
 
+    describe '#base_complexity' do
+      context 'with no gitaly calls' do
+        it 'defaults to 1' do
+          field = described_class.new(name: 'test', type: GraphQL::STRING_TYPE, null: true)
+
+          expect(field.base_complexity).to eq 1
+        end
+      end
+
+      context 'with a gitaly call' do
+        it 'adds 1 to the default value' do
+          field = described_class.new(name: 'test', type: GraphQL::STRING_TYPE, null: true, calls_gitaly: true)
+
+          expect(field.base_complexity).to eq 2
+        end
+      end
+    end
+
     it 'has specified value' do
       field = described_class.new(name: 'test', type: GraphQL::STRING_TYPE, null: true, complexity: 12)
 
@@ -52,5 +70,46 @@ describe Types::BaseField do
         end
       end
     end
+
+    context 'calls_gitaly' do
+      context 'for fields with a resolver' do
+        it 'adds 1 if true' do
+          with_gitaly_field = described_class.new(name: 'test', type: GraphQL::STRING_TYPE, resolver_class: resolver, null: true, calls_gitaly: true)
+          without_gitaly_field = described_class.new(name: 'test', type: GraphQL::STRING_TYPE, resolver_class: resolver, null: true)
+          base_result = without_gitaly_field.to_graphql.complexity.call({}, {}, 2)
+
+          expect(with_gitaly_field.to_graphql.complexity.call({}, {}, 2)).to eq base_result + 1
+        end
+      end
+
+      context 'for fields without a resolver' do
+        it 'adds 1 if true' do
+          field = described_class.new(name: 'test', type: GraphQL::STRING_TYPE, null: true, calls_gitaly: true)
+
+          expect(field.to_graphql.complexity).to eq 2
+        end
+      end
+
+      it 'defaults to false' do
+        field = described_class.new(name: 'test', type: GraphQL::STRING_TYPE, null: true)
+
+        expect(field.base_complexity).to eq Types::BaseField::DEFAULT_COMPLEXITY
+      end
+
+      context 'with declared constant complexity value' do
+        it 'has complexity set to that constant' do
+          field = described_class.new(name: 'test', type: GraphQL::STRING_TYPE, null: true, complexity: 12)
+
+          expect(field.to_graphql.complexity).to eq 12
+        end
+
+        it 'does not raise an error even with Gitaly calls' do
+          allow(Gitlab::GitalyClient).to receive(:get_request_count).and_return([0, 1])
+          field = described_class.new(name: 'test', type: GraphQL::STRING_TYPE, null: true, complexity: 12)
+
+          expect(field.to_graphql.complexity).to eq 12
+        end
+      end
+    end
   end
 end

spec/lib/gitlab/graphql/calls_gitaly/instrumentation_spec.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+require 'spec_helper'
+
+describe Gitlab::Graphql::CallsGitaly::Instrumentation do
+  subject { described_class.new }
+
+  describe '#calls_gitaly_check' do
+    let(:gitaly_field) { Types::BaseField.new(name: 'test', type: GraphQL::STRING_TYPE, null: true, calls_gitaly: true) }
+    let(:no_gitaly_field) { Types::BaseField.new(name: 'test', type: GraphQL::STRING_TYPE, null: true, calls_gitaly: false) }
+
+    context 'if there are no Gitaly calls' do
+      it 'does not raise an error if calls_gitaly is false' do
+        expect { subject.send(:calls_gitaly_check, no_gitaly_field, 0) }.not_to raise_error
+      end
+    end
+
+    context 'if there is at least 1 Gitaly call' do
+      it 'raises an error if calls_gitaly: is false or not defined' do
+        expect { subject.send(:calls_gitaly_check, no_gitaly_field, 1) }.to raise_error(/specify a constant complexity or add `calls_gitaly: true`/)
+      end
+    end
+  end
+end

spec/requests/api/graphql_spec.rb

@@ -131,4 +131,35 @@ describe 'GraphQL' do
       end
     end
   end
+
+  describe 'testing for Gitaly calls' do
+    let(:project) { create(:project, :repository) }
+    let(:user) { create(:user) }
+
+    let(:query) do
+      graphql_query_for('project', { 'fullPath' => project.full_path }, %w(id))
+    end
+
+    before do
+      project.add_developer(user)
+    end
+
+    it_behaves_like 'a working graphql query' do
+      before do
+        post_graphql(query, current_user: user)
+      end
+    end
+
+    context 'when Gitaly is called' do
+      before do
+        allow(Gitlab::GitalyClient).to receive(:get_request_count).and_return(1, 2)
+      end
+
+      it "logs a warning that the 'calls_gitaly' field declaration is missing" do
+        expect(Gitlab::Sentry).to receive(:track_exception).once
+
+        post_graphql(query, current_user: user)
+      end
+    end
+  end
 end