allow disabling/enabling group runners per project

app/controllers/projects/runners_controller.rb

@@ -52,6 +52,12 @@ class Projects::RunnersController < Projects::ApplicationController
     redirect_to project_settings_ci_cd_path(@project)
   end
 
+  def toggle_group_runners
+    project.toggle!(:group_runners_enabled)
+
+    redirect_to project_settings_ci_cd_path(@project)
+  end
+
   protected
 
   def set_runner

app/views/projects/runners/_group_runners.html.haml

@@ -4,6 +4,16 @@
   GitLab Group Runners can execute code for all the projects in this group.
   They can be managed using the #{link_to 'Runners API', help_page_path('api/runners.md')}.
 
+  - if @project.group
+    %hr
+    - if @project.group_runners_enabled?
+      = link_to toggle_group_runners_project_runners_path(@project), class: 'btn btn-warning', method: :post do
+        Disable group Runners
+    - else
+      = link_to toggle_group_runners_project_runners_path(@project), class: 'btn btn-success', method: :post do
+        Enable group Runners
+      for this project
+
 - if !@project.group
   This project does not belong to a group and can therefore not make use of group Runners.
 

config/routes/project.rb

@@ -410,6 +410,7 @@ constraints(::Constraints::ProjectUrlConstrainer.new) do
 
         collection do
           post :toggle_shared_runners
+          post :toggle_group_runners
         end
       end
 

spec/features/runners_spec.rb

@@ -219,6 +219,20 @@ feature 'Runners' do
         expect(page).to have_content 'Available group Runners : 1'
         expect(page).to have_content 'group-runner'
       end
+
+      scenario 'group runners may be disabled for a project' do
+        visit runners_path(project)
+
+        click_on 'Disable group Runners'
+
+        expect(page).to have_content 'Enable group Runners'
+        expect(project.reload.group_runners_enabled).to be false
+
+        click_on 'Enable group Runners'
+
+        expect(page).to have_content 'Disable group Runners'
+        expect(project.reload.group_runners_enabled).to be true
+      end
     end
   end
 end