Migrate project pages metadata when asked for virtual domain

Create project_pages_metadatum on the fly when asked for
PagesDomain#pages_virtual_domain.

Update the internal Pages API to return 204 No Content for custom
domains that do not have pages deployed yet.

4 files changed, 71 insertions, 18 deletions

diff --git a/app/models/pages_domain.rb b/app/models/pages_domain.rb
index 142967f886d..2ee3a2a1ae3 100644
--- a/app/models/pages_domain.rb
+++ b/app/models/pages_domain.rb
@@ -186,11 +186,21 @@ class PagesDomain < ApplicationRecord
   end
 
   def pages_virtual_domain
+    return unless pages_deployed?
+
     Pages::VirtualDomain.new([project], domain: self)
   end
 
   private
 
+  def pages_deployed?
+    return true if project.project_pages_metadatum&.deployed?
+
+    Project.where(id: project_id).migrate_project_pages_metadata
+
+    project.reset.project_pages_metadatum&.deployed?
+  end
+
   def set_verification_code
     return if self.verification_code.present?
 
diff --git a/lib/api/internal/pages.rb b/lib/api/internal/pages.rb
index 6b6ccce0275..2ba6b65f0c5 100644
--- a/lib/api/internal/pages.rb
+++ b/lib/api/internal/pages.rb
@@ -27,7 +27,10 @@ module API
             host = Namespace.find_by_pages_host(params[:host]) || PagesDomain.find_by_domain(params[:host])
             not_found! unless host
 
-            present host.pages_virtual_domain, with: Entities::Internal::Pages::VirtualDomain
+            virtual_domain = host.pages_virtual_domain
+            no_content! unless virtual_domain
+
+            present virtual_domain, with: Entities::Internal::Pages::VirtualDomain
           end
         end
       end
diff --git a/spec/models/pages_domain_spec.rb b/spec/models/pages_domain_spec.rb
index 519c519fbcf..8237f926ed3 100644
--- a/spec/models/pages_domain_spec.rb
+++ b/spec/models/pages_domain_spec.rb
@@ -538,4 +538,32 @@ describe PagesDomain do
       )
     end
   end
+
+  describe '#pages_virtual_domain' do
+    let(:project) { create(:project) }
+    let(:pages_domain) { create(:pages_domain, project: project) }
+
+    context 'when there are no pages deployed for the project' do
+      it 'returns nil when there are no pages deployed for the project' do
+        expect(pages_domain.pages_virtual_domain).to be_nil
+      end
+    end
+
+    context 'when there are pages deployed for the project' do
+      before do
+        generic_commit_status = create(:generic_commit_status, :success, stage: 'deploy', name: 'pages:deploy')
+        generic_commit_status.update!(project: project)
+      end
+
+      it 'returns the virual domain' do
+        expect(pages_domain.pages_virtual_domain).to be_an_instance_of(Pages::VirtualDomain)
+      end
+
+      it 'migrates project pages metadata' do
+        expect { pages_domain.pages_virtual_domain }.to change {
+          project.project_pages_metadatum&.deployed
+        }.from(nil).to(true)
+      end
+    end
+  end
 end
diff --git a/spec/requests/api/internal/pages_spec.rb b/spec/requests/api/internal/pages_spec.rb
index 4efa4276be7..c6abe9a1088 100644
--- a/spec/requests/api/internal/pages_spec.rb
+++ b/spec/requests/api/internal/pages_spec.rb
@@ -43,6 +43,11 @@ describe API::Internal::Pages do
           super(host, headers)
         end
 
+        def deploy_pages(project)
+          generic_commit_status = create(:generic_commit_status, :success, stage: 'deploy', name: 'pages:deploy')
+          generic_commit_status.update!(project: project)
+        end
+
         context 'not existing host' do
           it 'responds with 404 Not Found' do
             query_host('pages.gitlab.io')
@@ -52,33 +57,40 @@ describe API::Internal::Pages do
         end
 
         context 'custom domain' do
-          it 'responds with the correct domain configuration' do
-            namespace = create(:namespace, name: 'gitlab-org')
-            project = create(:project, namespace: namespace, name: 'gitlab-ce')
-            pages_domain = create(:pages_domain, domain: 'pages.gitlab.io', project: project)
+          let(:namespace) { create(:namespace, name: 'gitlab-org') }
+          let(:project) { create(:project, namespace: namespace, name: 'gitlab-ce') }
+          let!(:pages_domain) { create(:pages_domain, domain: 'pages.gitlab.io', project: project) }
 
-            query_host('pages.gitlab.io')
+          context 'when there are no pages deployed for the related project' do
+            it 'responds with 204 No Content' do
+              query_host('pages.gitlab.io')
 
-            expect(response).to have_gitlab_http_status(200)
-            expect(response).to match_response_schema('internal/pages/virtual_domain')
+              expect(response).to have_gitlab_http_status(204)
+            end
+          end
 
-            expect(json_response['certificate']).to eq(pages_domain.certificate)
-            expect(json_response['key']).to eq(pages_domain.key)
+          context 'when there are  pages deployed for the related project' do
+            it 'responds with the correct domain configuration' do
+              deploy_pages(project)
 
-            lookup_path = json_response['lookup_paths'][0]
-            expect(lookup_path['prefix']).to eq('/')
-            expect(lookup_path['source']['path']).to eq('gitlab-org/gitlab-ce/public/')
+              query_host('pages.gitlab.io')
+
+              expect(response).to have_gitlab_http_status(200)
+              expect(response).to match_response_schema('internal/pages/virtual_domain')
+
+              expect(json_response['certificate']).to eq(pages_domain.certificate)
+              expect(json_response['key']).to eq(pages_domain.key)
+
+              lookup_path = json_response['lookup_paths'][0]
+              expect(lookup_path['prefix']).to eq('/')
+              expect(lookup_path['source']['path']).to eq('gitlab-org/gitlab-ce/public/')
+            end
           end
         end
 
         context 'namespaced domain' do
           let(:group) { create(:group, name: 'mygroup') }
 
-          def deploy_pages(project)
-            generic_commit_status = create(:generic_commit_status, :success, stage: 'deploy', name: 'pages:deploy')
-            generic_commit_status.update!(project: project)
-          end
-
           before do
             allow(Settings.pages).to receive(:host).and_return('gitlab-pages.io')
             allow(Gitlab.config.pages).to receive(:url).and_return("http://gitlab-pages.io")