Remove group_clusters feature flag

Now we have terminals for instance and group clusters we can remove the
FF now. Deploying to group clusters has been working without complaints
too.

app/controllers/groups/clusters_controller.rb

@@ -4,7 +4,6 @@ class Groups::ClustersController < Clusters::ClustersController
   include ControllerWithCrossProjectAccessCheck
 
   prepend_before_action :group
-  prepend_before_action :check_group_clusters_feature_flag!
   requires_cross_project_access
 
   layout 'group'
@@ -18,12 +17,4 @@ class Groups::ClustersController < Clusters::ClustersController
   def group
     @group ||= find_routable!(Group, params[:group_id] || params[:id])
   end
-
-  def check_group_clusters_feature_flag!
-    render_404 unless group_clusters_enabled?
-  end
-
-  def group_clusters_enabled?
-    group.group_clusters_enabled?
-  end
 end

app/helpers/groups_helper.rb

@@ -142,7 +142,7 @@ module GroupsHelper
       can?(current_user, "read_group_#{resource}".to_sym, @group)
     end
 
-    if can?(current_user, :read_cluster, @group) && @group.group_clusters_enabled?
+    if can?(current_user, :read_cluster, @group)
       links << :kubernetes
     end
 

app/models/concerns/deployment_platform.rb

@@ -13,7 +13,7 @@ module DeploymentPlatform
 
   def find_deployment_platform(environment)
     find_cluster_platform_kubernetes(environment: environment) ||
-      find_group_cluster_platform_kubernetes_with_feature_guard(environment: environment) ||
+      find_group_cluster_platform_kubernetes(environment: environment) ||
       find_instance_cluster_platform_kubernetes_with_feature_guard(environment: environment)
   end
 
@@ -23,12 +23,6 @@ module DeploymentPlatform
       .last&.platform_kubernetes
   end
 
-  def find_group_cluster_platform_kubernetes_with_feature_guard(environment: nil)
-    return unless group_clusters_enabled?
-
-    find_group_cluster_platform_kubernetes(environment: environment)
-  end
-
   # EE would override this and utilize environment argument
   def find_group_cluster_platform_kubernetes(environment: nil)
     Clusters::Cluster.enabled.default_environment.ancestor_clusters_for_clusterable(self)

app/models/group.rb

@@ -410,10 +410,6 @@ class Group < Namespace
     ensure_runners_token!
   end
 
-  def group_clusters_enabled?
-    Feature.enabled?(:group_clusters, root_ancestor, default_enabled: true)
-  end
-
   def project_creation_level
     super || ::Gitlab::CurrentSettings.default_project_creation
   end

app/models/project.rb

@@ -306,7 +306,6 @@ class Project < ApplicationRecord
   delegate :add_guest, :add_reporter, :add_developer, :add_maintainer, :add_role, to: :team
   delegate :add_master, to: :team # @deprecated
   delegate :group_runners_enabled, :group_runners_enabled=, :group_runners_enabled?, to: :ci_cd_settings
-  delegate :group_clusters_enabled?, to: :group, allow_nil: true
   delegate :root_ancestor, to: :namespace, allow_nil: true
   delegate :last_pipeline, to: :commit, allow_nil: true
   delegate :external_dashboard_url, to: :metrics_setting, allow_nil: true, prefix: true

spec/controllers/groups/clusters_controller_spec.rb

@@ -20,23 +20,6 @@ describe Groups::ClustersController do
       get :index, params: params.reverse_merge(group_id: group)
     end
 
-    context 'when feature flag is not enabled' do
-      before do
-        stub_feature_flags(group_clusters: false)
-      end
-
-      it 'renders 404' do
-        go
-
-        expect(response).to have_gitlab_http_status(404)
-      end
-    end
-
-    context 'when feature flag is enabled' do
-      before do
-        stub_feature_flags(group_clusters: true)
-      end
-
     describe 'functionality' do
       context 'when group has one or more clusters' do
         let(:group) { create(:group) }
@@ -86,7 +69,6 @@ describe Groups::ClustersController do
         end
       end
     end
-    end
 
     describe 'security' do
       let(:cluster) { create(:cluster, :provided_by_gcp, cluster_type: :group_type, groups: [group]) }

spec/models/concerns/deployment_platform_spec.rb

@@ -82,16 +82,6 @@ describe DeploymentPlatform do
           end
         end
       end
-
-      context 'feature flag disabled' do
-        before do
-          stub_feature_flags(group_clusters: false)
-        end
-
-        it 'returns nil' do
-          is_expected.to be_nil
-        end
-      end
     end
   end
 end

spec/models/group_spec.rb

@@ -866,35 +866,6 @@ describe Group do
     end
   end
 
-  describe '#group_clusters_enabled?' do
-    before do
-      # Override global stub in spec/spec_helper.rb
-      expect(Feature).to receive(:enabled?).and_call_original
-    end
-
-    subject { group.group_clusters_enabled? }
-
-    it { is_expected.to be_truthy }
-
-    context 'explicitly disabled for root ancestor' do
-      before do
-        feature = Feature.get(:group_clusters)
-        feature.disable(group.root_ancestor)
-      end
-
-      it { is_expected.to be_falsey }
-    end
-
-    context 'explicitly disabled for root ancestor' do
-      before do
-        feature = Feature.get(:group_clusters)
-        feature.enable(group.root_ancestor)
-      end
-
-      it { is_expected.to be_truthy }
-    end
-  end
-
   describe '#first_auto_devops_config' do
     using RSpec::Parameterized::TableSyntax
 

spec/models/project_spec.rb

@@ -497,7 +497,6 @@ describe Project do
 
     it { is_expected.to delegate_method(:members).to(:team).with_prefix(true) }
     it { is_expected.to delegate_method(:name).to(:owner).with_prefix(true).with_arguments(allow_nil: true) }
-    it { is_expected.to delegate_method(:group_clusters_enabled?).to(:group).with_arguments(allow_nil: true) }
     it { is_expected.to delegate_method(:root_ancestor).to(:namespace).with_arguments(allow_nil: true) }
     it { is_expected.to delegate_method(:last_pipeline).to(:commit).with_arguments(allow_nil: true) }
   end