Merge branch '33678-allow-revert-back-to-basic-search' into 'master'

Allow user to revert back to non-ElasticSearch search

See merge request gitlab-org/gitlab!19136

app/helpers/search_helper.rb

 # frozen_string_literal: true
 
 module SearchHelper
+  SEARCH_PERMITTED_PARAMS = [:search, :scope, :project_id, :group_id, :repository_ref, :snippets].freeze
+
   def search_autocomplete_opts(term)
     return unless current_user
 
@@ -200,7 +202,7 @@ module SearchHelper
     search_params = params
       .merge(search)
       .merge({ scope: scope })
-      .permit(:search, :scope, :project_id, :group_id, :repository_ref, :snippets)
+      .permit(SEARCH_PERMITTED_PARAMS)
 
     if @scope == scope
       li_class = 'active'

app/views/search/_results.html.haml

 - if @search_objects.to_a.empty?
   = render partial: "search/results/empty"
   = render_if_exists 'shared/promotions/promote_advanced_search'
+  = render_if_exists 'search/form_revert_to_basic'
 - else
   .row-content-block.d-md-flex.text-left.align-items-center
     - unless @search_objects.is_a?(Kaminari::PaginatableWithoutCount)

doc/integration/elasticsearch.md

@@ -583,3 +583,12 @@ Here are some common pitfalls and how to overcome them:
   AWS has [fixed limits](https://docs.aws.amazon.com/elasticsearch-service/latest/developerguide/aes-limits.html)
   for this setting ("Maximum Size of HTTP Request Payloads"), based on the size of
   the underlying instance.
+
+### Reverting to basic search
+
+Sometimes there may be issues with your Elasticsearch index data and as such
+GitLab will allow you to revert to "basic search" when there are no search
+results and assuming that basic search is supported in that scope. This "basic
+search" will behave as though you don't have Elasticsearch enabled at all for
+your instance and search using other data sources (ie. Postgres data and Git
+data).

ee/app/helpers/ee/search_helper.rb

@@ -3,6 +3,8 @@ module EE
   module SearchHelper
     extend ::Gitlab::Utils::Override
 
+    SWITCH_TO_BASIC_SEARCHABLE_TABS = %w[projects issues merge_requests milestones users].freeze
+
     override :search_filter_input_options
     def search_filter_input_options(type)
       options = super
@@ -60,6 +62,23 @@ module EE
       end
     end
 
+    def revert_to_basic_search_filter_url
+      search_params = params
+        .permit(::SearchHelper::SEARCH_PERMITTED_PARAMS)
+        .merge(basic_search: true)
+
+      search_path(search_params)
+    end
+
+    def show_switch_to_basic_search?(search_service)
+      return false unless ::Feature.enabled?(:switch_to_basic_search, default_enabled: false)
+      return false unless search_service.use_elasticsearch?
+
+      return true if @project
+
+      search_service.scope.in?(SWITCH_TO_BASIC_SEARCHABLE_TABS)
+    end
+
     private
 
     def search_multiple_assignees?(type)

ee/app/services/concerns/search/elasticsearchable.rb

+# frozen_string_literal: true
+
+module Search
+  module Elasticsearchable
+    def use_elasticsearch?
+      return false if params[:basic_search]
+
+      ::Gitlab::CurrentSettings.search_using_elasticsearch?(scope: elasticsearchable_scope)
+    end
+
+    def elasticsearchable_scope
+      raise NotImplementedError
+    end
+  end
+end

ee/app/services/ee/search/global_service.rb

@@ -5,6 +5,7 @@ module EE
     module GlobalService
       extend ::Gitlab::Utils::Override
       include ::Gitlab::Utils::StrongMemoize
+      include ::Search::Elasticsearchable
 
       override :execute
       def execute
@@ -19,8 +20,8 @@ module EE
         )
       end
 
-      def use_elasticsearch?
-        ::Gitlab::CurrentSettings.search_using_elasticsearch?(scope: nil)
+      def elasticsearchable_scope
+        nil
       end
 
       def elastic_projects

ee/app/services/ee/search/group_service.rb

@@ -5,9 +5,9 @@ module EE
     module GroupService
       extend ::Gitlab::Utils::Override
 
-      override :use_elasticsearch?
-      def use_elasticsearch?
-        ::Gitlab::CurrentSettings.search_using_elasticsearch?(scope: group)
+      override :elasticsearchable_scope
+      def elasticsearchable_scope
+        group
       end
 
       override :elastic_projects

ee/app/services/ee/search/project_service.rb

@@ -4,6 +4,7 @@ module EE
   module Search
     module ProjectService
       extend ::Gitlab::Utils::Override
+      include ::Search::Elasticsearchable
 
       override :execute
       def execute
@@ -17,9 +18,8 @@ module EE
         )
       end
 
-      # This method is used in the top-level SearchService, so cannot be in-lined into #execute
-      def use_elasticsearch?
-        ::Gitlab::CurrentSettings.search_using_elasticsearch?(scope: project)
+      def elasticsearchable_scope
+        project
       end
     end
   end

ee/app/services/ee/search/snippet_service.rb

@@ -12,9 +12,9 @@ module EE
         ::Gitlab::Elastic::SnippetSearchResults.new(current_user, params[:search], elastic_projects, nil, true)
       end
 
-      # This method is used in the top-level SearchService, so cannot be in-lined into #execute
-      def use_elasticsearch?
-        ::Gitlab::CurrentSettings.search_using_elasticsearch?(scope: nil)
+      override :elasticsearchable_scope
+      def elasticsearchable_scope
+        nil
       end
     end
   end

ee/app/views/search/_form_revert_to_basic.html.haml

+- if show_switch_to_basic_search?(search_service)
+  - begin_link = '<a href="%{url}">'.html_safe % { url: revert_to_basic_search_filter_url }
+  - end_link = '</a>'.html_safe
+  %p.text-center
+    = _('You can try again using %{begin_link}basic search%{end_link}').html_safe % { begin_link: begin_link, end_link: end_link }

ee/spec/features/search/elastic/global_search_spec.rb

@@ -221,4 +221,33 @@ describe 'Global elastic search', :elastic do
       expect(page).to have_content('Users 0')
     end
   end
+
+  context 'when no results are returned' do
+    it 'allows basic search without Elasticsearch' do
+      visit dashboard_projects_path
+
+      submit_search('project')
+
+      # Project won't be found since ES index is not up to date
+      expect(page).not_to have_content('Projects 1')
+
+      # Since there are no results you have the option to instead use basic
+      # search
+      click_link 'basic search'
+
+      # Project is found now that we are using basic search
+      expect(page).to have_content('Projects 1')
+    end
+
+    context 'when performing Commits search' do
+      it 'does not allow basic search' do
+        visit dashboard_projects_path
+
+        submit_search('project')
+        select_search_scope('Commits')
+
+        expect(page).not_to have_link('basic search')
+      end
+    end
+  end
 end

ee/spec/helpers/search_helper_spec.rb

@@ -175,4 +175,47 @@ describe SearchHelper do
       it_behaves_like 'returns old message'
     end
   end
+
+  describe '#show_switch_to_basic_search?' do
+    let(:use_elasticsearch) { true }
+    let(:scope) { 'commits' }
+    let(:search_service) { instance_double(Search::GlobalService, use_elasticsearch?: use_elasticsearch, scope: scope) }
+    subject { show_switch_to_basic_search?(search_service) }
+
+    before do
+      stub_feature_flags(switch_to_basic_search: true)
+    end
+
+    context 'when :switch_to_basic_search feature is disabled' do
+      before do
+        stub_feature_flags(switch_to_basic_search: false)
+      end
+
+      it { is_expected.to eq(false) }
+    end
+
+    context 'when not currently using elasticsearch' do
+      let(:use_elasticsearch) { false }
+
+      it { is_expected.to eq(false) }
+    end
+
+    context 'when project scope' do
+      before do
+        @project = create(:project)
+      end
+
+      it { is_expected.to eq(true) }
+    end
+
+    context 'when commits tab' do
+      it { is_expected.to eq(false) }
+    end
+
+    context 'when issues tab' do
+      let(:scope) { 'issues' }
+
+      it { is_expected.to eq(true) }
+    end
+  end
 end

ee/spec/services/search/global_service_spec.rb

@@ -15,7 +15,7 @@ describe Search::GlobalService do
 
   it_behaves_like 'EE search service shared examples', ::Gitlab::SearchResults, ::Gitlab::Elastic::SearchResults do
     let(:scope) { nil }
-    let(:service) { described_class.new(user, search: '*') }
+    let(:service) { described_class.new(user, params) }
   end
 
   context 'visibility', :elastic do

ee/spec/services/search/group_service_spec.rb

@@ -16,7 +16,7 @@ describe Search::GroupService, :elastic do
 
   it_behaves_like 'EE search service shared examples', ::Gitlab::GroupSearchResults, ::Gitlab::Elastic::GroupSearchResults do
     let(:scope) { create(:group) }
-    let(:service) { described_class.new(user, scope, search: '*') }
+    let(:service) { described_class.new(user, scope, params) }
   end
 
   describe 'group search' do

ee/spec/services/search/project_service_spec.rb

@@ -14,7 +14,7 @@ describe Search::ProjectService do
   it_behaves_like 'EE search service shared examples', ::Gitlab::ProjectSearchResults, ::Gitlab::Elastic::ProjectSearchResults do
     let(:user) { scope.owner }
     let(:scope) { create(:project) }
-    let(:service) { described_class.new(scope, user, search: '*') }
+    let(:service) { described_class.new(scope, user, params) }
   end
 
   context 'visibility', :elastic do

ee/spec/services/search/snippet_service_spec.rb

@@ -6,6 +6,6 @@ describe Search::SnippetService do
   it_behaves_like 'EE search service shared examples', ::Gitlab::SnippetSearchResults, ::Gitlab::Elastic::SnippetSearchResults do
     let(:user) { create(:user) }
     let(:scope) { nil }
-    let(:service) { described_class.new(user, search: '*') }
+    let(:service) { described_class.new(user, params) }
   end
 end

ee/spec/support/shared_examples/services/search_service_shared_examples.rb

 # frozen_string_literal: true
 
 RSpec.shared_examples 'EE search service shared examples' do |normal_results, elasticsearch_results|
+  let(:params) { { search: '*' } }
+
   describe '#use_elasticsearch?' do
     it 'delegates to Gitlab::CurrentSettings.search_using_elasticsearch?' do
       expect(Gitlab::CurrentSettings)
@@ -10,6 +12,17 @@ RSpec.shared_examples 'EE search service shared examples' do |normal_results, el
 
       expect(service.use_elasticsearch?).to eq(:value)
     end
+
+    context 'when requesting basic_search' do
+      let(:params) { { search: '*', basic_search: 'true' } }
+
+      it 'returns false' do
+        expect(Gitlab::CurrentSettings)
+          .not_to receive(:search_using_elasticsearch?)
+
+        expect(service.use_elasticsearch?).to eq(false)
+      end
+    end
   end
 
   describe '#execute' do

locale/gitlab.pot

@@ -19209,6 +19209,9 @@ msgstr ""
 msgid "You can test your .gitlab-ci.yml in %{linkStart}CI Lint%{linkEnd}."
 msgstr ""
 
+msgid "You can try again using %{begin_link}basic search%{end_link}"
+msgstr ""
+
 msgid "You cannot access the raw file. Please wait a minute."
 msgstr ""