Do not allow applications for group clusters

These applications will need further work in future issues to enable
them to work with groups of projects.

app/services/clusters/applications/create_service.rb

@@ -42,7 +42,16 @@ module Clusters
       def builders
         {
           "helm" => -> (cluster) { cluster.application_helm || cluster.build_application_helm },
-          "ingress" => -> (cluster) { cluster.application_ingress || cluster.build_application_ingress },
+          "ingress" => -> (cluster) { cluster.application_ingress || cluster.build_application_ingress }
+        }.tap do |hash|
+          hash.merge!(project_builders) if cluster.project_type?
+        end
+      end
+
+      # These applications will need extra configuration to enable them to work
+      # with groups of projects
+      def project_builders
+        {
           "prometheus" => -> (cluster) { cluster.application_prometheus || cluster.build_application_prometheus },
           "runner" => -> (cluster) { cluster.application_runner || cluster.build_application_runner },
           "jupyter" => -> (cluster) { cluster.application_jupyter || cluster.build_application_jupyter },

spec/services/clusters/applications/create_service_spec.rb

@@ -60,14 +60,6 @@ describe Clusters::Applications::CreateService do
       end
     end
 
-    context 'invalid application' do
-      let(:params) { { application: 'non-existent' } }
-
-      it 'raises an error' do
-        expect { subject }.to raise_error(Clusters::Applications::CreateService::InvalidApplicationError)
-      end
-    end
-
     context 'knative application' do
       let(:params) do
         {
@@ -100,5 +92,39 @@ describe Clusters::Applications::CreateService do
         expect { subject }.to raise_error(Clusters::Applications::CreateService::InvalidApplicationError)
       end
     end
+
+    context 'group cluster' do
+      let(:cluster) { create(:cluster, :provided_by_gcp, :group) }
+
+      using RSpec::Parameterized::TableSyntax
+
+      before do
+        allow_any_instance_of(Clusters::Applications::ScheduleInstallationService).to receive(:execute)
+      end
+
+      where(:application, :association, :allowed) do
+        'helm'       | :application_helm       | true
+        'ingress'    | :application_ingress    | true
+        'runner'     | :application_runner     | false
+        'jupyter'    | :application_jupyter    | false
+        'prometheus' | :application_prometheus | false
+      end
+
+      with_them do
+        let(:params) { { application: application } }
+
+        it 'executes for each application' do
+          if allowed
+            expect do
+              subject
+
+              cluster.reload
+            end.to change(cluster, association)
+          else
+            expect { subject }.to raise_error(Clusters::Applications::CreateService::InvalidApplicationError)
+          end
+        end
+      end
+    end
   end
 end