Always show "Clear cluster cache" button

This adds the ability to clear the cluster cache for non-managed
clusters. This is necessary as they may have residual cached namespaces
interfering with namespace customization.

See https://gitlab.com/gitlab-org/gitlab/-/issues/208734

app/views/clusters/clusters/_advanced_settings.html.haml

@@ -26,13 +26,16 @@
           = link_to _('More information'), help_page_path('user/clusters/management_project.md'), target: '_blank'
       = field.submit _('Save changes'), class: 'btn btn-success'
 
-  - if @cluster.managed?
-    .sub-section.form-group
-      %h4
-        = s_('ClusterIntegration|Clear cluster cache')
-      %p
-        = s_("ClusterIntegration|Clear the local cache of namespace and service accounts. This is necessary if your integration has become out of sync. The cache is repopulated during the next CI job that requires namespace and service accounts.")
-      = link_to(s_('ClusterIntegration|Clear cluster cache'), clusterable.clear_cluster_cache_path(@cluster), method: :delete, class: 'btn btn-primary')
+  .sub-section.form-group
+    %h4
+      = s_('ClusterIntegration|Clear cluster cache')
+    %p
+      = s_("ClusterIntegration|Clear the local cache of namespace and service accounts.")
+      - if @cluster.managed?
+        = s_("ClusterIntegration|This is necessary if your integration has become out of sync. The cache is repopulated during the next CI job that requires namespace and service accounts.")
+      - else
+        = s_("ClusterIntegration|This is necessary to clear existing environment-namespace associations from clusters previously managed by GitLab.")
+    = link_to(s_('ClusterIntegration|Clear cluster cache'), clusterable.clear_cluster_cache_path(@cluster), method: :delete, class: 'btn btn-primary')
 
   .sub-section.form-group
     %h4.text-danger

changelogs/unreleased/always-show-clear-cluster-cache-button.yml

+---
+title: Always show the "Clear cluster cache" button among the advanced Kubernetes cluster configuration options
+merge_request: 43619
+author:
+type: changed

locale/gitlab.pot

@@ -5520,7 +5520,7 @@ msgstr ""
 msgid "ClusterIntegration|Clear cluster cache"
 msgstr ""
 
-msgid "ClusterIntegration|Clear the local cache of namespace and service accounts. This is necessary if your integration has become out of sync. The cache is repopulated during the next CI job that requires namespace and service accounts."
+msgid "ClusterIntegration|Clear the local cache of namespace and service accounts."
 msgstr ""
 
 msgid "ClusterIntegration|Cluster management project (alpha)"
@@ -6219,6 +6219,12 @@ msgstr ""
 msgid "ClusterIntegration|This account must have permissions to create a Kubernetes cluster in the %{link_to_container_project} specified below"
 msgstr ""
 
+msgid "ClusterIntegration|This is necessary if your integration has become out of sync. The cache is repopulated during the next CI job that requires namespace and service accounts."
+msgstr ""
+
+msgid "ClusterIntegration|This is necessary to clear existing environment-namespace associations from clusters previously managed by GitLab."
+msgstr ""
+
 msgid "ClusterIntegration|This option will allow you to install applications on RBAC clusters."
 msgstr ""
 

spec/features/clusters/cluster_detail_page_spec.rb

@@ -87,6 +87,7 @@ RSpec.describe 'Clusterable > Show page' do
       within('#advanced-settings-section') do
         expect(page).to have_content('Google Kubernetes Engine')
         expect(page).to have_content('Manage your Kubernetes cluster by visiting')
+        expect_common_advanced_options
       end
     end
   end
@@ -117,6 +118,7 @@ RSpec.describe 'Clusterable > Show page' do
       within('#advanced-settings-section') do
         expect(page).not_to have_content('Google Kubernetes Engine')
         expect(page).not_to have_content('Manage your Kubernetes cluster by visiting')
+        expect_common_advanced_options
       end
     end
   end
@@ -176,4 +178,14 @@ RSpec.describe 'Clusterable > Show page' do
       let(:cluster) { create(:cluster, :provided_by_user, :instance) }
     end
   end
+
+  private
+
+  def expect_common_advanced_options
+    aggregate_failures do
+      expect(page).to have_content('Cluster management project')
+      expect(page).to have_content('Clear cluster cache')
+      expect(page).to have_content('Remove Kubernetes cluster integration')
+    end
+  end
 end