Add and refactor Kubernetes menu

In this commit we're refactoring the Kuebernetes
menu in the group sidebar.

We're moving away from partial defined logic to object
contained one. Now menus are defined in objects that
will contain all the information instead of in partials.

app/views/layouts/nav/sidebar/_group_menus.html.haml

-- if group_sidebar_link?(:kubernetes)
-  = nav_link(controller: [:clusters]) do
-    = link_to group_clusters_path(@group) do
-      .nav-icon-container
-        = sprite_icon('cloud-gear')
-      %span.nav-item-name
-        = _('Kubernetes')
-    %ul.sidebar-sub-level-items.is-fly-out-only
-      = nav_link(controller: [:clusters], html_options: { class: "fly-out-top-item" } ) do
-        = link_to group_clusters_path(@group), title: _('Kubernetes'), class: 'shortcuts-kubernetes' do
-          %strong.fly-out-top-item-name
-            = _('Kubernetes')
-
 = render 'groups/sidebar/packages'
 
 = render 'layouts/nav/sidebar/analytics_links', links: group_analytics_navbar_links(@group, current_user)

lib/sidebars/groups/menus/kubernetes_menu.rb

+# frozen_string_literal: true
+
+module Sidebars
+  module Groups
+    module Menus
+      class KubernetesMenu < ::Sidebars::Menu
+        override :link
+        def link
+          group_clusters_path(context.group)
+        end
+
+        override :title
+        def title
+          _('Kubernetes')
+        end
+
+        override :sprite_icon
+        def sprite_icon
+          'cloud-gear'
+        end
+
+        override :render?
+        def render?
+          can?(context.current_user, :read_cluster, context.group)
+        end
+
+        override :extra_container_html_options
+        def extra_container_html_options
+          {
+            class: 'shortcuts-kubernetes'
+          }
+        end
+
+        override :active_routes
+        def active_routes
+          { controller: :clusters }
+        end
+      end
+    end
+  end
+end

lib/sidebars/groups/panel.rb

@@ -11,6 +11,7 @@ module Sidebars
         add_menu(Sidebars::Groups::Menus::IssuesMenu.new(context))
         add_menu(Sidebars::Groups::Menus::MergeRequestsMenu.new(context))
         add_menu(Sidebars::Groups::Menus::CiCdMenu.new(context))
+        add_menu(Sidebars::Groups::Menus::KubernetesMenu.new(context))
       end
 
       override :render_raw_menus_partial

spec/lib/sidebars/groups/menus/kubernetes_menu_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Sidebars::Groups::Menus::KubernetesMenu do
+  let_it_be(:owner) { create(:user) }
+  let_it_be(:group) do
+    build(:group, :private).tap do |g|
+      g.add_owner(owner)
+    end
+  end
+
+  let(:user) { owner }
+  let(:context) { Sidebars::Groups::Context.new(current_user: user, container: group) }
+  let(:menu) { described_class.new(context) }
+
+  describe '#render?' do
+    context 'when user can read clusters' do
+      it 'returns true' do
+        expect(menu.render?).to eq true
+      end
+    end
+
+    context 'when user cannot read clusters rules' do
+      let(:user) { nil }
+
+      it 'returns false' do
+        expect(menu.render?).to eq false
+      end
+    end
+  end
+end

spec/views/layouts/nav/sidebar/_group.html.haml_spec.rb

@@ -100,4 +100,12 @@ RSpec.describe 'layouts/nav/sidebar/_group' do
       expect(rendered).to have_link('Runners', href: group_runners_path(group))
     end
   end
+
+  describe 'Kubernetes menu' do
+    it 'has a link to the group cluster list path' do
+      render
+
+      expect(rendered).to have_link('Kubernetes', href: group_clusters_path(group))
+    end
+  end
 end