Add PackageFileRegistryFinder for GraphQL API

But write it generically for the Geo Self-Service Framework. Similar
code will be needed for all Geo registry classes.

ee/app/finders/geo/framework_registry_finder.rb

+# frozen_string_literal: true
+
+module Geo
+  # Used to provide registry data for GraphQL queries.
+  #
+  module FrameworkRegistryFinder
+    extend ActiveSupport::Concern
+
+    included do
+      include Gitlab::Allowable
+
+      delegate :registry_class, to: :replicator_class
+
+      def initialize(current_user, params = {})
+        @current_user = current_user
+        @params = params
+      end
+
+      def execute
+        return registry_class.none unless can?(current_user, :read_all_geo)
+
+        registry_entries = init_collection
+
+        registry_entries = by_id(registry_entries)
+
+        registry_entries.ordered
+      end
+
+      private
+
+      attr_reader :current_user, :params
+
+      def replicator_class
+        Gitlab::Geo::Replicator.for_class_name(self.class.name)
+      end
+
+      def init_collection
+        registry_class.all
+      end
+
+      def by_id(registry_entries)
+        return registry_entries if params[:ids].nil?
+        return registry_class.none if params[:ids].empty?
+
+        registry_entries.id_in(params[:ids])
+      end
+    end
+  end
+end

ee/app/finders/geo/package_file_registry_finder.rb

+# frozen_string_literal: true
+
+module Geo
+  class PackageFileRegistryFinder
+    include FrameworkRegistryFinder
+  end
+end

ee/app/models/geo/package_file_registry.rb

@@ -16,6 +16,7 @@ class Geo::PackageFileRegistry < Geo::BaseRegistry
   scope :failed, -> { with_state(:failed) }
   scope :synced, -> { with_state(:synced) }
   scope :retry_due, -> { where(arel_table[:retry_at].eq(nil).or(arel_table[:retry_at].lt(Time.now))) }
+  scope :ordered, -> { order(:id) }
 
   state_machine :state, initial: :pending do
     state :pending, value: STATE_VALUES[:pending]

ee/lib/gitlab/geo/replicator.rb

@@ -12,6 +12,8 @@ module Gitlab
     class Replicator
       include ::Gitlab::Geo::LogHelpers
 
+      CLASS_SUFFIXES = %w(RegistryFinder RegistriesResolver).freeze
+
       attr_reader :model_record_id
       delegate :model, to: :class
 
@@ -63,6 +65,10 @@ module Gitlab
         const_get("::Geo::#{replicable_name.camelize}Registry", false)
       end
 
+      def self.registry_finder_class
+        const_get("::Geo::#{replicable_name.camelize}RegistryFinder", false)
+      end
+
       # Given a `replicable_name`, return the corresponding replicator
       #
       # @param [String] replicable_name the replicable slug
@@ -89,6 +95,21 @@ module Gitlab
         model.count
       end
 
+      # @example Given `Geo::PackageFileRegistryFinder`, this returns
+      #   `::Geo::PackageFileReplicator`
+      # @example Given `Resolver::Geo::PackageFileRegistriesResolver`, this
+      #   returns `::Geo::PackageFileReplicator`
+      #
+      # @return [Class] a Replicator subclass
+      def self.for_class_name(class_name)
+        name = class_name.demodulize
+
+        # Strip suffixes is dumb but will probably work for a while
+        CLASS_SUFFIXES.each { |suffix| name.delete_suffix!(suffix) }
+
+        const_get("::Geo::#{name}Replicator", false)
+      end
+
       # @param [ActiveRecord::Base] model_record
       # @param [Integer] model_record_id
       def initialize(model_record: nil, model_record_id: nil)

ee/spec/finders/geo/package_file_registry_finder_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Geo::PackageFileRegistryFinder do
+  it_behaves_like 'a framework registry finder', :package_file_registry
+end

ee/spec/lib/gitlab/geo/replicator_spec.rb

@@ -22,9 +22,9 @@ describe Gitlab::Geo::Replicator do
 
   context 'with defined events' do
     before do
-      stub_const('DummyReplicator', Class.new(Gitlab::Geo::Replicator))
+      stub_const('Geo::DummyReplicator', Class.new(Gitlab::Geo::Replicator))
 
-      DummyReplicator.class_eval do
+      Geo::DummyReplicator.class_eval do
         event :test
         event :another_test
 
@@ -37,7 +37,7 @@ describe Gitlab::Geo::Replicator do
     end
 
     context 'event DSL' do
-      subject { DummyReplicator }
+      subject { Geo::DummyReplicator }
 
       describe '.supported_events' do
         it 'expects :test event to be supported' do
@@ -68,7 +68,7 @@ describe Gitlab::Geo::Replicator do
 
           include Gitlab::Geo::ReplicableModel
 
-          with_replicator DummyReplicator
+          with_replicator Geo::DummyReplicator
         end
       end
 
@@ -79,12 +79,12 @@ describe Gitlab::Geo::Replicator do
       end
 
       it 'instantiates a replicator into the model' do
-        expect(subject.replicator).to be_a(DummyReplicator)
+        expect(subject.replicator).to be_a(Geo::DummyReplicator)
       end
     end
 
     describe '#publish' do
-      subject { DummyReplicator.new }
+      subject { Geo::DummyReplicator.new }
 
       context 'when geo_self_service_framework feature is disabled' do
         before do
@@ -120,7 +120,7 @@ describe Gitlab::Geo::Replicator do
     end
 
     describe '#consume' do
-      subject { DummyReplicator.new }
+      subject { Geo::DummyReplicator.new }
 
       it 'accepts valid attributes' do
         expect { subject.consume(:test, user: 'something', other: 'something else') }.not_to raise_error
@@ -132,5 +132,19 @@ describe Gitlab::Geo::Replicator do
         subject.consume(:test, user: 'something', other: 'something else')
       end
     end
+
+    describe '.for_class_name' do
+      context 'when given a Geo RegistryFinder' do
+        it 'returns the corresponding Replicator class' do
+          expect(described_class.for_class_name('Geo::DummyRegistryFinder')).to eq(Geo::DummyReplicator)
+        end
+      end
+
+      context 'when given a Geo RegistriesResolver"' do
+        it 'returns the corresponding Replicator class' do
+          expect(described_class.for_class_name('Geo::DummyRegistriesResolver')).to eq(Geo::DummyReplicator)
+        end
+      end
+    end
   end
 end

ee/spec/support/shared_examples/finders/geo/framework_registry_finder_shared_examples.rb

+# frozen_string_literal: true
+
+RSpec.shared_examples 'a framework registry finder' do |registry_factory|
+  include ::EE::GeoHelpers
+
+  let!(:registry1) { create(registry_factory) }
+  let!(:registry2) { create(registry_factory) }
+  let!(:registry3) { create(registry_factory) }
+  let(:params) { {} }
+
+  subject(:registries) { described_class.new(user, params).execute }
+
+  describe '#execute' do
+    context 'when user cannot read all Geo' do
+      let_it_be(:user) { create(:user) }
+
+      it { is_expected.to be_empty }
+    end
+
+    context 'when user can read all Geo' do
+      let_it_be(:user) { create(:user, :admin) }
+
+      context 'with an ids param' do
+        let(:params) { { ids: [registry3.id, registry1.id] } }
+
+        it 'returns specified registries' do
+          expect(registries.to_a).to eq([registry1, registry3])
+        end
+      end
+
+      context 'without an ids param' do
+        it 'returns all registries' do
+          expect(registries.to_a).to eq([registry1, registry2, registry3])
+        end
+      end
+    end
+  end
+end