Add "Enable pipeline suggestion banner" setting

app/helpers/application_settings_helper.rb

@@ -400,7 +400,8 @@ module ApplicationSettingsHelper
       :user_deactivation_emails_enabled,
       :sidekiq_job_limiter_mode,
       :sidekiq_job_limiter_compression_threshold_bytes,
-      :sidekiq_job_limiter_limit_bytes
+      :sidekiq_job_limiter_limit_bytes,
+      :suggest_pipeline_enabled
     ].tap do |settings|
       settings << :deactivate_dormant_users unless Gitlab.com?
     end

app/models/application_setting_implementation.rb

@@ -159,6 +159,7 @@ module ApplicationSettingImplementation
         spam_check_endpoint_enabled: false,
         spam_check_endpoint_url: nil,
         spam_check_api_key: nil,
+        suggest_pipeline_enabled: true,
         terminal_max_session_time: 0,
         throttle_authenticated_api_enabled: false,
         throttle_authenticated_api_period_in_seconds: 3600,

app/views/admin/application_settings/_ci_cd.html.haml

@@ -69,5 +69,12 @@
       %p.form-text.text-muted
         = _("The default CI/CD configuration file and path for new projects.").html_safe
         = link_to sprite_icon('question-o'), help_page_path('ci/pipelines/settings', anchor: 'specify-a-custom-cicd-configuration-file'), target: '_blank'
+    .form-group
+      .form-check
+        = f.check_box :suggest_pipeline_enabled, class: 'form-check-input'
+        = f.label :suggest_pipeline_enabled, class: 'form-check-label' do
+          = s_('AdminSettings|Enable pipeline suggestion banner')
+        .form-text.text-muted
+          = s_('AdminSettings|Display a banner on merge requests in projects with no pipelines to initiate steps to add a .gitlab-ci.yml file.')
 
   = f.submit _('Save changes'), class: "gl-button btn btn-confirm"

doc/user/admin_area/settings/continuous_integration.md

@@ -216,6 +216,20 @@ of your GitLab instance (`.gitlab-ci.yml` if not set):
 
 It is also possible to specify a [custom CI/CD configuration file for a specific project](../../../ci/pipelines/settings.md#specify-a-custom-cicd-configuration-file).
 
+## Enable or disable the pipeline suggestion banner
+
+By default, a banner displays in merge requests with no pipeline suggesting a
+walkthrough on how to add one.
+
+![Suggest pipeline banner](img/suggest_pipeline_banner.png)
+
+To enable or disable the banner:
+
+1. On the top bar, select **Menu > Admin**.
+1. On the left sidebar, select **Settings > CI/CD**.
+1. Select or clear the **Enable pipeline suggestion banner** checkbox.
+1. Select **Save changes**.
+
 ## Required pipeline configuration **(PREMIUM SELF)**
 
 WARNING:

locale/gitlab.pot

@@ -2401,9 +2401,15 @@ msgstr ""
 msgid "AdminSettings|Disable public access to Pages sites"
 msgstr ""
 
+msgid "AdminSettings|Display a banner on merge requests in projects with no pipelines to initiate steps to add a .gitlab-ci.yml file."
+msgstr ""
+
 msgid "AdminSettings|Domain verification is an essential security measure for public GitLab sites. Users are required to demonstrate they control a domain before it is enabled. %{link_start}Learn more.%{link_end}"
 msgstr ""
 
+msgid "AdminSettings|Enable pipeline suggestion banner"
+msgstr ""
+
 msgid "AdminSettings|Enable shared runners for new projects"
 msgstr ""
 

spec/features/admin/admin_settings_spec.rb

@@ -314,12 +314,14 @@ RSpec.describe 'Admin updates settings' do
           check 'Default to Auto DevOps pipeline for all projects'
           fill_in 'application_setting_auto_devops_domain', with: 'domain.com'
           uncheck 'Keep the latest artifacts for all jobs in the latest successful pipelines'
+          uncheck 'Enable pipeline suggestion banner'
           click_button 'Save changes'
         end
 
         expect(current_settings.auto_devops_enabled?).to be true
         expect(current_settings.auto_devops_domain).to eq('domain.com')
         expect(current_settings.keep_latest_artifact).to be false
+        expect(current_settings.suggest_pipeline_enabled).to be false
         expect(page).to have_content "Application settings saved successfully"
       end