Extract Helm::ClientCommand for shared commands

app/models/clusters/concerns/application_status.rb

@@ -66,6 +66,9 @@ module Clusters
           end
           before_transition any => [:installed, :updated] do |app_status, _|
+            # When installing any application we are also performing an update
+            # of tiller (see Gitlab::Kubernetes::Helm::ClientCommand) so
+            # therefore we need to reflect that in the database.
             app_status.cluster.application_helm.update!(version: Gitlab::Kubernetes::Helm::HELM_VERSION)
           end
         end

lib/gitlab/kubernetes/helm/client_command.rb

+module Gitlab
+  module Kubernetes
+    module Helm
+      module ClientCommand
+        def init_command
+          # Here we are always upgrading to the latest version of Tiller when
+          # installing an app. We ensure the helm version stored in the
+          # database is correct by also updating this after transition to
+          # :installed,:updated in Clusters::Concerns::ApplicationStatus
+          'helm init --upgrade --tiller-namespace gitlab-managed-apps'
+        end
+
+        def wait_for_tiller_command
+          # This is necessary to give Tiller time to restart after upgrade.
+          # Ideally we'd be able to use --wait but cannot because of
+          # https://github.com/helm/helm/issues/4855
+          'sleep 30'
+        end
+
+        def repository_command
+          ['helm', 'repo', 'add', name, repository].shelljoin if repository
+        end
+      end
+    end
+  end
+end

lib/gitlab/kubernetes/helm/install_command.rb

@@ -3,6 +3,7 @@ module Gitlab
     module Helm
       class InstallCommand
         include BaseCommand
+        include ClientCommand
         attr_reader :name, :files, :chart, :version, :repository, :preinstall, :postinstall
@@ -20,10 +21,7 @@ module Gitlab
         def generate_script
           super + [
             init_command,
-            # Sleep is necessary to give Tiller time to restart after upgrade.
-            # Ideally we'd be able to use --wait but cannot because of
-            # https://github.com/helm/helm/issues/4855
-            sleep_command,
+            wait_for_tiller_command,
             repository_command,
             repository_update_command,
             preinstall_command,
@@ -38,18 +36,6 @@ module Gitlab
         private
-        def init_command
-          'helm init --upgrade --tiller-namespace gitlab-managed-apps'
-        end
-
-        def sleep_command
-          'sleep 30'
-        end
-
-        def repository_command
-          ['helm', 'repo', 'add', name, repository].shelljoin if repository
-        end
-
         def repository_update_command
           'helm repo update' if repository
         end

lib/gitlab/kubernetes/helm/upgrade_command.rb

@@ -5,6 +5,7 @@ module Gitlab
     module Helm
       class UpgradeCommand
         include BaseCommand
+        include ClientCommand
         attr_reader :name, :chart, :version, :repository, :files
@@ -20,10 +21,7 @@ module Gitlab
         def generate_script
           super + [
             init_command,
-            # Sleep is necessary to give Tiller time to restart after upgrade.
-            # Ideally we'd be able to use --wait but cannot because of
-            # https://github.com/helm/helm/issues/4855
-            sleep_command,
+            wait_for_tiller_command,
             repository_command,
             script_command
           ].compact.join("\n")
@@ -39,18 +37,6 @@ module Gitlab
         private
-        def init_command
-          'helm init --upgrade --tiller-namespace gitlab-managed-apps'
-        end
-
-        def sleep_command
-          'sleep 30'
-        end
-
-        def repository_command
-          "helm repo add #{name} #{repository}" if repository
-        end
-
         def script_command
           upgrade_flags = "#{optional_version_flag}#{optional_tls_flags}" \
             " --reset-values" \