5 files changed, 38 insertions, 14 deletions
diff --git a/app/models/clusters/applications/prometheus.rb b/app/models/clusters/applications/prometheus.rb
index 26bf73f4dd8..f50adb4693d 100644
--- a/app/models/clusters/applications/prometheus.rb
+++ b/app/models/clusters/applications/prometheus.rb
@@ -52,24 +52,16 @@ module Clusters
         )
       end
 
-      def upgrade_command(values)
+      def upgrade_command(replaced_values: nil)
         ::Gitlab::Kubernetes::Helm::UpgradeCommand.new(
           name,
           version: VERSION,
           chart: chart,
           rbac: cluster.platform_kubernetes_rbac?,
-          files: files_with_replaced_values(values)
+          files: replaced_values ? files_with_replaced_values(replaced_values) : files
         )
       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
 
diff --git a/app/models/clusters/applications/runner.rb b/app/models/clusters/applications/runner.rb
index 2cf8d47bded..5b4a5ad8ba1 100644
--- a/app/models/clusters/applications/runner.rb
+++ b/app/models/clusters/applications/runner.rb
@@ -40,13 +40,13 @@ module Clusters
         )
       end
 
-      def upgrade_command
+      def upgrade_command(replaced_values: nil)
         ::Gitlab::Kubernetes::Helm::UpgradeCommand.new(
           name,
           version: VERSION,
           rbac: cluster.platform_kubernetes_rbac?,
           chart: chart,
-          files: files,
+          files: replaced_values ? files_with_replaced_values(replaced_values) : files,
           repository: repository
         )
       end
diff --git a/app/models/clusters/concerns/application_data.rb b/app/models/clusters/concerns/application_data.rb
index 52498f123ff..556bf14888b 100644
--- a/app/models/clusters/concerns/application_data.rb
+++ b/app/models/clusters/concerns/application_data.rb
@@ -24,6 +24,14 @@ module Clusters
           end
         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
+
         private
 
         def certificate_files
diff --git a/app/services/clusters/applications/base_helm_service.rb b/app/services/clusters/applications/base_helm_service.rb
index 8a71730d5ec..c04fb8914f7 100644
--- a/app/services/clusters/applications/base_helm_service.rb
+++ b/app/services/clusters/applications/base_helm_service.rb
@@ -46,8 +46,8 @@ module Clusters
         @install_command ||= app.install_command
       end
 
-      def upgrade_command(new_values = "")
-        app.upgrade_command(new_values)
+      def upgrade_command(replaced_values: nil)
+        app.upgrade_command(replaced_values: replaced_values)
       end
     end
   end
diff --git a/app/services/clusters/applications/update_service.rb b/app/services/clusters/applications/update_service.rb
new file mode 100644
index 00000000000..fecc13f979d
--- /dev/null
+++ b/app/services/clusters/applications/update_service.rb
@@ -0,0 +1,24 @@
+# frozen_string_literal: true
+
+module Clusters
+  module Applications
+    class UpdateService < BaseHelmService
+      def execute
+        return if app.updating?
+
+        begin
+          app.make_updating!
+          helm_api.update(upgrade_command)
+
+          ::ClusterWaitForAppUpdateWorker.perform_in(::ClusterWaitForAppUpdateWorker::INTERVAL, app.name, app.id)
+        rescue Kubeclient::HttpError => e
+          log_error(e)
+          app.make_update_errored!("Kubernetes error: #{e.error_code}")
+        rescue StandardError => e
+          log_error(e)
+          app.make_update_errored!("Can't start installation process.")
+        end
+      end
+    end
+  end
+end