Remove `rbac_clusters` feature flag

Now that Auto DevOps can run in a RBAC enabled cluster from
https://gitlab.com/gitlab-org/gitlab-ce/issues/51942, we can now remove
the FF.

As the flag only governed if UI elements would appear or not when
creating/adding existing clusters; the effect of removing the FF would
be that the checkbox to choose to enable RBAC clusters will now always
appear.

Remove FF stubs from specs

Improve spec context names

app/helpers/clusters_helper.rb

@@ -13,8 +13,4 @@ module ClustersHelper
       render 'projects/clusters/gcp_signup_offer_banner'
     end
   end
-
-  def rbac_clusters_feature_enabled?
-    Feature.enabled?(:rbac_clusters)
-  end
 end

app/views/projects/clusters/gcp/_form.html.haml

@@ -61,7 +61,6 @@
       %p.form-text.text-muted
         = s_('ClusterIntegration|Learn more about %{help_link_start_machine_type}machine types%{help_link_end} and %{help_link_start_pricing}pricing%{help_link_end}.').html_safe % { help_link_start_machine_type: help_link_start % { url: machine_type_link_url }, help_link_start_pricing: help_link_start % { url: pricing_link_url }, help_link_end: help_link_end }
 
-    - if rbac_clusters_feature_enabled?
     .form-group
       .form-check
         = provider_gcp_field.check_box :legacy_abac, { class: 'form-check-input' }, false, true

app/views/projects/clusters/gcp/_show.html.haml

@@ -37,7 +37,6 @@
       = platform_kubernetes_field.label :namespace, s_('ClusterIntegration|Project namespace (optional, unique)')
       = platform_kubernetes_field.text_field :namespace, class: 'form-control', placeholder: s_('ClusterIntegration|Project namespace')
 
-    - if rbac_clusters_feature_enabled?
     .form-group
       .form-check
         = platform_kubernetes_field.check_box :authorization_type, { class: 'form-check-input', disabled: true }, 'rbac', 'abac'

app/views/projects/clusters/user/_form.html.haml

@@ -25,7 +25,6 @@
       = platform_kubernetes_field.label :namespace, s_('ClusterIntegration|Project namespace (optional, unique)'), class: 'label-bold'
       = platform_kubernetes_field.text_field :namespace, class: 'form-control', placeholder: s_('ClusterIntegration|Project namespace')
 
-    - if rbac_clusters_feature_enabled?
     .form-group
       .form-check
         = platform_kubernetes_field.check_box :authorization_type, { class: 'form-check-input' }, 'rbac', 'abac'

app/views/projects/clusters/user/_show.html.haml

@@ -26,7 +26,6 @@
       = platform_kubernetes_field.label :namespace, s_('ClusterIntegration|Project namespace (optional, unique)'), class: 'label-bold'
       = platform_kubernetes_field.text_field :namespace, class: 'form-control', placeholder: s_('ClusterIntegration|Project namespace')
 
-    - if rbac_clusters_feature_enabled?
     .form-group
       .form-check
         = platform_kubernetes_field.check_box :authorization_type, { class: 'form-check-input', disabled: true }, 'rbac', 'abac'

changelogs/unreleased/51009-remove-rbac-clusters-feature-flag.yml

+---
+title: Remove 'rbac_clusters' feature flag
+merge_request: 22096
+author:
+type: changed

spec/features/projects/clusters/gcp_spec.rb

@@ -84,10 +84,8 @@ describe 'Gcp Cluster', :js do
 
         it_behaves_like 'valid cluster gcp form'
 
-        context 'rbac_clusters feature flag is enabled' do
+        context 'RBAC is enabled for the cluster' do
           before do
-            stub_feature_flags(rbac_clusters: true)
-
             check 'cluster_provider_gcp_attributes_legacy_abac'
           end
 

spec/features/projects/clusters/user_spec.rb

@@ -44,10 +44,8 @@ describe 'User Cluster', :js do
 
       it_behaves_like 'valid cluster user form'
 
-      context 'rbac_clusters feature flag is enabled' do
+      context 'RBAC is enabled for the cluster' do
         before do
-          stub_feature_flags(rbac_clusters: true)
-
           check 'cluster_platform_kubernetes_attributes_authorization_type'
         end
 

spec/support/services/clusters/create_service_shared.rb

@@ -30,10 +30,6 @@ shared_context 'invalid cluster create params' do
 end
 
 shared_examples 'create cluster service success' do
-  before do
-    stub_feature_flags(rbac_clusters: false)
-  end
-
   it 'creates a cluster object and performs a worker' do
     expect(ClusterProvisionWorker).to receive(:perform_async)