Make `gitlab:elastic:index` enable `elasticsearch_indexing`

Before this change, the `gitlab:elastic:index` command would always fail
the on the first run, as it needed a setting to be set in the UI in the
middle of the execution.

Now this setting will be set automatically, thus making this rake task
the easiest way to populate the Elasticsearch index for a small GitLab
instance.

doc/integration/elasticsearch.md

@@ -245,7 +245,7 @@ This will delete your existing indexes.
 
 If the database size is less than 500 MiB, and the size of all hosted repos is less than 5 GiB:
 
-1. [Enable **Elasticsearch indexing** and configure your host and port](#enabling-elasticsearch).
+1. [Configure your Elasticsearch host and port](#enabling-elasticsearch).
 1. Index your data:
 
    ```shell
@@ -424,7 +424,7 @@ The following are some available Rake tasks:
 
 | Task                                                                                                                                                    | Description                                                                                                                                                                               |
 |:--------------------------------------------------------------------------------------------------------------------------------------------------------|:------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
-| [`sudo gitlab-rake gitlab:elastic:index`](https://gitlab.com/gitlab-org/gitlab/blob/master/ee/lib/tasks/gitlab/elastic.rake)                            | Wrapper task for `gitlab:elastic:create_empty_index`, `gitlab:elastic:clear_index_status`, `gitlab:elastic:index_projects`, and `gitlab:elastic:index_snippets`.                          |
+| [`sudo gitlab-rake gitlab:elastic:index`](https://gitlab.com/gitlab-org/gitlab/blob/master/ee/lib/tasks/gitlab/elastic.rake)                            | Enables Elasticsearch Indexing and run `gitlab:elastic:create_empty_index`, `gitlab:elastic:clear_index_status`, `gitlab:elastic:index_projects`, and `gitlab:elastic:index_snippets`.                          |
 | [`sudo gitlab-rake gitlab:elastic:index_projects`](https://gitlab.com/gitlab-org/gitlab/blob/master/ee/lib/tasks/gitlab/elastic.rake)                   | Iterates over all projects and queues Sidekiq jobs to index them in the background.                                                                                                       |
 | [`sudo gitlab-rake gitlab:elastic:index_projects_status`](https://gitlab.com/gitlab-org/gitlab/blob/master/ee/lib/tasks/gitlab/elastic.rake)            | Determines the overall status of the indexing. It is done by counting the total number of indexed projects, dividing by a count of the total number of projects, then multiplying by 100. |
 | [`sudo gitlab-rake gitlab:elastic:clear_index_status`](https://gitlab.com/gitlab-org/gitlab/blob/master/ee/lib/tasks/gitlab/elastic.rake)               | Deletes all instances of IndexStatus for all projects.                                                                                                                                    |

ee/changelogs/unreleased/216275-elasticsearch-rake-task-gitlab-elastic-index-won-t-work-as-desi.yml

+---
+title: Automatically enable Elasticsearch indexing with 'gitlab:elastic:index'
+merge_request: 35342
+author:
+type: changed

ee/lib/tasks/gitlab/elastic.rake

@@ -9,6 +9,18 @@ namespace :gitlab do
 
       Rake::Task["gitlab:elastic:recreate_index"].invoke
       Rake::Task["gitlab:elastic:clear_index_status"].invoke
+
+      # enable `elasticsearch_indexing` if it isn't
+      unless Gitlab::CurrentSettings.elasticsearch_indexing?
+        ApplicationSettings::UpdateService.new(
+          Gitlab::CurrentSettings.current_application_settings,
+          nil,
+          { elasticsearch_indexing: true }
+        ).execute
+
+        puts "Setting `elasticsearch_indexing` has been enabled."
+      end
+
       Rake::Task["gitlab:elastic:index_projects"].invoke
       Rake::Task["gitlab:elastic:index_snippets"].invoke
     end

ee/spec/tasks/gitlab/elastic_rake_spec.rb

@@ -5,78 +5,87 @@ require 'rake_helper'
 RSpec.describe 'gitlab:elastic namespace rake tasks', :elastic do
   before do
     Rake.application.rake_require 'tasks/gitlab/elastic'
-    stub_ee_application_setting(elasticsearch_indexing: true)
   end
 
-  describe 'index' do
-    it 'calls all indexing tasks in order' do
-      expect(Rake::Task['gitlab:elastic:recreate_index']).to receive(:invoke).ordered
-      expect(Rake::Task['gitlab:elastic:clear_index_status']).to receive(:invoke).ordered
-      expect(Rake::Task['gitlab:elastic:index_projects']).to receive(:invoke).ordered
-      expect(Rake::Task['gitlab:elastic:index_snippets']).to receive(:invoke).ordered
-
-      run_rake_task 'gitlab:elastic:index'
+  context "with elasticsearch_indexing enabled" do
+    before do
+      stub_ee_application_setting(elasticsearch_indexing: true)
     end
-  end
 
-  describe 'index_projects' do
-    let(:project1) { create :project }
-    let(:project2) { create :project }
-    let(:project3) { create :project }
+    describe 'index' do
+      it 'calls all indexing tasks in order' do
+        expect(Rake::Task['gitlab:elastic:recreate_index']).to receive(:invoke).ordered
+        expect(Rake::Task['gitlab:elastic:clear_index_status']).to receive(:invoke).ordered
+        expect(Rake::Task['gitlab:elastic:index_projects']).to receive(:invoke).ordered
+        expect(Rake::Task['gitlab:elastic:index_snippets']).to receive(:invoke).ordered
 
-    before do
-      Sidekiq::Testing.disable! do
-        project1
-        project2
+        run_rake_task 'gitlab:elastic:index'
       end
     end
 
-    it 'queues jobs for each project batch' do
-      expect(Elastic::ProcessInitialBookkeepingService).to receive(:backfill_projects!).with(
-        project1, project2
-      )
-
-      run_rake_task 'gitlab:elastic:index_projects'
-    end
+    describe 'index_projects' do
+      let(:project1) { create :project }
+      let(:project2) { create :project }
+      let(:project3) { create :project }
 
-    context 'with limited indexing enabled' do
       before do
         Sidekiq::Testing.disable! do
           project1
           project2
-          project3
+        end
+      end
+
+      it 'queues jobs for each project batch' do
+        expect(Elastic::ProcessInitialBookkeepingService).to receive(:backfill_projects!).with(project1, project2)
 
-          create :elasticsearch_indexed_project, project: project1
-          create :elasticsearch_indexed_namespace, namespace: project3.namespace
+        run_rake_task 'gitlab:elastic:index_projects'
+      end
+
+      context 'with limited indexing enabled' do
+        before do
+          Sidekiq::Testing.disable! do
+            project1
+            project2
+            project3
+
+            create :elasticsearch_indexed_project, project: project1
+            create :elasticsearch_indexed_namespace, namespace: project3.namespace
+          end
+
+          stub_ee_application_setting(elasticsearch_limit_indexing: true)
         end
 
-        stub_ee_application_setting(elasticsearch_limit_indexing: true)
+        it 'does not queue jobs for projects that should not be indexed' do
+          expect(Elastic::ProcessInitialBookkeepingService).to receive(:backfill_projects!).with(project1, project3)
+
+          run_rake_task 'gitlab:elastic:index_projects'
+        end
       end
+    end
 
-      it 'does not queue jobs for projects that should not be indexed' do
-        expect(Elastic::ProcessInitialBookkeepingService).to receive(:backfill_projects!).with(
-          project1, project3
-        )
+    describe 'index_snippets' do
+      it 'indexes snippets' do
+        expect(Snippet).to receive(:es_import)
 
-        run_rake_task 'gitlab:elastic:index_projects'
+        run_rake_task 'gitlab:elastic:index_snippets'
       end
     end
-  end
 
-  describe 'index_snippets' do
-    it 'indexes snippets' do
-      expect(Snippet).to receive(:es_import)
+    describe 'recreate_index' do
+      it 'calls all related subtasks in order' do
+        expect(Rake::Task['gitlab:elastic:delete_index']).to receive(:invoke).ordered
+        expect(Rake::Task['gitlab:elastic:create_empty_index']).to receive(:invoke).ordered
 
-      run_rake_task 'gitlab:elastic:index_snippets'
+        run_rake_task 'gitlab:elastic:recreate_index'
+      end
     end
   end
 
-  describe 'recreate_index' do
-    it 'calls all related subtasks in order' do
-      expect(Rake::Task['gitlab:elastic:delete_index']).to receive(:invoke).ordered
-      expect(Rake::Task['gitlab:elastic:create_empty_index']).to receive(:invoke).ordered
-
-      run_rake_task 'gitlab:elastic:recreate_index'
+  context "with elasticsearch_indexing is disabled" do
+    it 'enables `elasticsearch_indexing`' do
+      expect { run_rake_task 'gitlab:elastic:index' }.to change {
+        Gitlab::CurrentSettings.elasticsearch_indexing?
+      }.from(false).to(true)
     end
   end
 end