Port generic upgrade functionality to CE

Port from EE generic upgrade related functionality used to upgrade Helm
applications

Remove memoization which could be incorrect

It looks like we are memoizing without regard to the method's argument
so this could result in an incorrect upgrade_command

Remove `const_get` indirection now we are no longer in EE

app/models/clusters/applications/prometheus.rb

@@ -25,13 +25,21 @@ module Clusters
       end
 
       def ready_status
-        [:installed]
+        [:installed, :updating, :updated, :update_errored]
       end
 
       def ready?
         ready_status.include?(status_name)
       end
 
+      def update_in_progress?
+        status_name == :updating
+      end
+
+      def update_errored?
+        status_name == :update_errored
+      end
+
       def chart
         'stable/prometheus'
       end
@@ -55,6 +63,24 @@ module Clusters
         )
       end
 
+      def upgrade_command(values)
+        ::Gitlab::Kubernetes::Helm::UpgradeCommand.new(
+          name,
+          version: VERSION,
+          chart: chart,
+          rbac: cluster.platform_kubernetes_rbac?,
+          files: files_with_replaced_values(values)
+        )
+      end
+
+      # Returns a copy of files where the values of 'values.yaml'
+      # are replaced by the argument.
+      #
+      # See #values for the data format required
+      def files_with_replaced_values(replaced_values)
+        files.merge('values.yaml': replaced_values)
+      end
+
       def prometheus_client
         return unless kube_client
 

app/services/clusters/applications/base_helm_service.rb

@@ -45,6 +45,10 @@ module Clusters
       def install_command
         @install_command ||= app.install_command
       end
+
+      def upgrade_command(new_values = "")
+        app.upgrade_command(new_values)
+      end
     end
   end
 end

spec/models/clusters/applications/prometheus_spec.rb

@@ -90,6 +90,24 @@ describe Clusters::Applications::Prometheus do
 
       expect(application).not_to be_ready
     end
+
+    it 'returns true when updating' do
+      application = build(:clusters_applications_prometheus, :updating, cluster: cluster)
+
+      expect(application).to be_ready
+    end
+
+    it 'returns true when updated' do
+      application = build(:clusters_applications_prometheus, :updated, cluster: cluster)
+
+      expect(application).to be_ready
+    end
+
+    it 'returns true when errored' do
+      application = build(:clusters_applications_prometheus, :update_errored, cluster: cluster)
+
+      expect(application).to be_ready
+    end
   end
 
   describe '#prometheus_client' do
@@ -197,6 +215,46 @@ describe Clusters::Applications::Prometheus do
     end
   end
 
+  describe '#upgrade_command' do
+    let(:prometheus) { build(:clusters_applications_prometheus) }
+    let(:values) { prometheus.values }
+
+    it 'returns an instance of Gitlab::Kubernetes::Helm::GetCommand' do
+      expect(prometheus.upgrade_command(values)).to be_an_instance_of(::Gitlab::Kubernetes::Helm::UpgradeCommand)
+    end
+
+    it 'should be initialized with 3 arguments' do
+      command = prometheus.upgrade_command(values)
+
+      expect(command.name).to eq('prometheus')
+      expect(command.chart).to eq('stable/prometheus')
+      expect(command.version).to eq('6.7.3')
+      expect(command.files).to eq(prometheus.files)
+    end
+  end
+
+  describe '#update_in_progress?' do
+    context 'when app is updating' do
+      it 'returns true' do
+        cluster = create(:cluster)
+        prometheus_app = build(:clusters_applications_prometheus, :updating, cluster: cluster)
+
+        expect(prometheus_app.update_in_progress?).to be true
+      end
+    end
+  end
+
+  describe '#update_errored?' do
+    context 'when app errored' do
+      it 'returns true' do
+        cluster = create(:cluster)
+        prometheus_app = build(:clusters_applications_prometheus, :update_errored, cluster: cluster)
+
+        expect(prometheus_app.update_errored?).to be true
+      end
+    end
+  end
+
   describe '#files' do
     let(:application) { create(:clusters_applications_prometheus) }
     let(:values) { subject[:'values.yaml'] }
@@ -211,4 +269,43 @@ describe Clusters::Applications::Prometheus do
       expect(values).to include('serverFiles')
     end
   end
+
+  describe '#files_with_replaced_values' do
+    let(:application) { build(:clusters_applications_prometheus) }
+    let(:files) { application.files }
+
+    subject { application.files_with_replaced_values({ hello: :world }) }
+
+    it 'does not modify #files' do
+      expect(subject[:'values.yaml']).not_to eq(files)
+      expect(files[:'values.yaml']).to eq(application.values)
+    end
+
+    it 'returns values.yaml with replaced values' do
+      expect(subject[:'values.yaml']).to eq({ hello: :world })
+    end
+
+    it 'should include cert files' do
+      expect(subject[:'ca.pem']).to be_present
+      expect(subject[:'ca.pem']).to eq(application.cluster.application_helm.ca_cert)
+
+      expect(subject[:'cert.pem']).to be_present
+      expect(subject[:'key.pem']).to be_present
+
+      cert = OpenSSL::X509::Certificate.new(subject[:'cert.pem'])
+      expect(cert.not_after).to be < 60.minutes.from_now
+    end
+
+    context 'when the helm application does not have a ca_cert' do
+      before do
+        application.cluster.application_helm.ca_cert = nil
+      end
+
+      it 'should not include cert files' do
+        expect(subject[:'ca.pem']).not_to be_present
+        expect(subject[:'cert.pem']).not_to be_present
+        expect(subject[:'key.pem']).not_to be_present
+      end
+    end
+  end
 end