Add delete modal to instance level serverless domain

app/views/admin/serverless/domains/_form.html.haml

@@ -66,3 +66,34 @@
           = _("Upload a private key for your certificate")
 
   = f.submit @domain.persisted? ? _('Save changes') : _('Add domain'), class: "btn btn-success js-serverless-domain-submit", disabled: @domain.persisted?
+  - if @domain.persisted?
+    %button.btn.btn-remove{ type: 'button', data: { toggle: 'modal', target: "#modal-delete-domain" } }
+      = _('Delete domain')
+
+-# haml-lint:disable NoPlainNodes
+- if @domain.persisted?
+  - domain_attached = @domain.serverless_domain_clusters.count > 0
+  .modal{ id: "modal-delete-domain", tabindex: -1 }
+    .modal-dialog
+      .modal-content
+        .modal-header
+          %h3.page-title= _('Delete serverless domain?')
+          %button.close{ type: "button", "data-dismiss": "modal", "aria-label" => _('Close') }
+            %span{ "aria-hidden": true } ×
+
+        .modal-body
+          - if domain_attached
+            = _("You must disassociate %{domain} from all clusters it is attached to before deletion.").html_safe % { domain: "<code>#{@domain.domain}</code>".html_safe }
+          - else
+            = _("You are about to delete %{domain} from your instance. This domain will no longer be available to any Knative application.").html_safe % { domain: "<code>#{@domain.domain}</code>".html_safe }
+
+        .modal-footer
+          %a{ href: '#', data: { dismiss: 'modal' }, class: 'btn btn-default' }
+            = _('Cancel')
+
+          = link_to _('Delete domain'),
+            admin_serverless_domain_path(@domain.id),
+            title: _('Delete'),
+            method: :delete,
+            class: "btn btn-remove",
+            disabled: domain_attached

locale/gitlab.pot

@@ -6446,6 +6446,9 @@ msgstr ""
 msgid "Delete comment"
 msgstr ""
 
+msgid "Delete domain"
+msgstr ""
+
 msgid "Delete license"
 msgstr ""
 
@@ -6458,6 +6461,9 @@ msgstr ""
 msgid "Delete project"
 msgstr ""
 
+msgid "Delete serverless domain?"
+msgstr ""
+
 msgid "Delete snippet"
 msgstr ""
 
@@ -23079,6 +23085,9 @@ msgstr ""
 msgid "You"
 msgstr ""
 
+msgid "You are about to delete %{domain} from your instance. This domain will no longer be available to any Knative application."
+msgstr ""
+
 msgid "You are about to transfer the control of your account to %{group_name} group. This action is NOT reversible, you won't be able to access any of your groups and projects outside of %{group_name} once this transfer is complete."
 msgstr ""
 
@@ -23355,6 +23364,9 @@ msgstr ""
 msgid "You must accept our Terms of Service and privacy policy in order to register an account"
 msgstr ""
 
+msgid "You must disassociate %{domain} from all clusters it is attached to before deletion."
+msgstr ""
+
 msgid "You must have maintainer access to force delete a lock"
 msgstr ""
 

spec/features/admin/admin_serverless_domains_spec.rb

@@ -56,4 +56,32 @@ describe 'Admin Serverless Domains', :js do
     expect(page).to have_content 'Domain was successfully updated'
     expect(page).to have_content '/CN=test-certificate'
   end
+
+  context 'when domain exists' do
+    let!(:domain) { create(:pages_domain, :instance_serverless) }
+
+    it 'Displays a modal when attempting to delete a domain' do
+      visit admin_serverless_domains_path
+
+      click_button 'Delete domain'
+
+      page.within '#modal-delete-domain' do
+        expect(page).to have_content "You are about to delete #{domain.domain} from your instance."
+        expect(page).to have_link('Delete domain')
+      end
+    end
+
+    it 'Displays a modal with disabled button if unable to delete a domain' do
+      create(:serverless_domain_cluster, pages_domain: domain)
+
+      visit admin_serverless_domains_path
+
+      click_button 'Delete domain'
+
+      page.within '#modal-delete-domain' do
+        expect(page).to have_content "You must disassociate #{domain.domain} from all clusters it is attached to before deletion."
+        expect(page).to have_link('Delete domain')
+      end
+    end
+  end
 end