Use Helm 3 for GitLab-managed apps in new clusters

With this change, any existing cluster will continue to use
Helm 2, while all new clusters will use Helm 3 for GitLab-managed apps.
Note that this only applies to GitLab-managed apps -- Auto DevOps
uses its own Helm version on a per-project basis.

The diff looks big because we split the Helm command classes into two
modules, V2 and V3, to allow them to evolve independently as long as
they both implement the same minimal interface.

The command classes in the V2 module should be exactly equal to their
old counterparts, besides the addition of BaseCommand#helm_version,
which the common Kubernetes pod generator uses to resolve the container
image.

The command classes in the V3 module are ports of the relevant subset of
commands. There are more classes in the V2 module because we carried
along support for in-cluster Tiller. This is currently unused, but may
be used to clean up Tiller if we decide to offer Helm 2 to 3 migration
in the product later on.

See also https://gitlab.com/gitlab-org/gitlab/-/issues/120021

app/models/clusters/applications/cert_manager.rb

@@ -30,7 +30,7 @@ module Clusters
       end
 
       def install_command
-        Gitlab::Kubernetes::Helm::InstallCommand.new(
+        helm_command_module::InstallCommand.new(
           name: 'certmanager',
           repository: repository,
           version: VERSION,
@@ -43,7 +43,7 @@ module Clusters
       end
 
       def uninstall_command
-        Gitlab::Kubernetes::Helm::DeleteCommand.new(
+        helm_command_module::DeleteCommand.new(
           name: 'certmanager',
           rbac: cluster.platform_kubernetes_rbac?,
           files: files,

app/models/clusters/applications/crossplane.rb

@@ -29,7 +29,7 @@ module Clusters
       end
 
       def install_command
-        Gitlab::Kubernetes::Helm::InstallCommand.new(
+        helm_command_module::InstallCommand.new(
           name: 'crossplane',
           repository: repository,
           version: VERSION,

app/models/clusters/applications/elastic_stack.rb

@@ -26,7 +26,7 @@ module Clusters
       end
 
       def install_command
-        Gitlab::Kubernetes::Helm::InstallCommand.new(
+        helm_command_module::InstallCommand.new(
           name: 'elastic-stack',
           version: VERSION,
           rbac: cluster.platform_kubernetes_rbac?,
@@ -39,7 +39,7 @@ module Clusters
       end
 
       def uninstall_command
-        Gitlab::Kubernetes::Helm::DeleteCommand.new(
+        helm_command_module::DeleteCommand.new(
           name: 'elastic-stack',
           rbac: cluster.platform_kubernetes_rbac?,
           files: files,
@@ -96,7 +96,7 @@ module Clusters
 
       def post_install_script
         [
-          "timeout -t60 sh /data/helm/elastic-stack/config/wait-for-elasticsearch.sh http://elastic-stack-elasticsearch-master:9200"
+          "timeout 60 sh /data/helm/elastic-stack/config/wait-for-elasticsearch.sh http://elastic-stack-elasticsearch-master:9200"
         ]
       end
 
@@ -116,7 +116,7 @@ module Clusters
         # Chart version 3.0.0 moves to our own chart at https://gitlab.com/gitlab-org/charts/elastic-stack
         # and is not compatible with pre-existing resources. We first remove them.
         [
-          Gitlab::Kubernetes::Helm::DeleteCommand.new(
+          helm_command_module::DeleteCommand.new(
             name: 'elastic-stack',
             rbac: cluster.platform_kubernetes_rbac?,
             files: files

app/models/clusters/applications/fluentd.rb

@@ -30,7 +30,7 @@ module Clusters
       end
 
       def install_command
-        Gitlab::Kubernetes::Helm::InstallCommand.new(
+        helm_command_module::InstallCommand.new(
           name: 'fluentd',
           repository: repository,
           version: VERSION,

app/models/clusters/applications/helm.rb

@@ -4,6 +4,8 @@ require 'openssl'
 
 module Clusters
   module Applications
+    # DEPRECATED: This model represents the Helm 2 Tiller server, and is no longer being actively used.
+    # It is being kept around for a potential cleanup of the unused Tiller server.
     class Helm < ApplicationRecord
       self.table_name = 'clusters_applications_helm'
 
@@ -49,7 +51,7 @@ module Clusters
       end
 
       def install_command
-        Gitlab::Kubernetes::Helm::InitCommand.new(
+        Gitlab::Kubernetes::Helm::V2::InitCommand.new(
           name: name,
           files: files,
           rbac: cluster.platform_kubernetes_rbac?
@@ -57,7 +59,7 @@ module Clusters
       end
 
       def uninstall_command
-        Gitlab::Kubernetes::Helm::ResetCommand.new(
+        Gitlab::Kubernetes::Helm::V2::ResetCommand.new(
           name: name,
           files: files,
           rbac: cluster.platform_kubernetes_rbac?
@@ -86,19 +88,19 @@ module Clusters
       end
 
       def create_keys_and_certs
-        ca_cert = Gitlab::Kubernetes::Helm::Certificate.generate_root
+        ca_cert = Gitlab::Kubernetes::Helm::V2::Certificate.generate_root
         self.ca_key = ca_cert.key_string
         self.ca_cert = ca_cert.cert_string
       end
 
       def tiller_cert
-        @tiller_cert ||= ca_cert_obj.issue(expires_in: Gitlab::Kubernetes::Helm::Certificate::INFINITE_EXPIRY)
+        @tiller_cert ||= ca_cert_obj.issue(expires_in: Gitlab::Kubernetes::Helm::V2::Certificate::INFINITE_EXPIRY)
       end
 
       def ca_cert_obj
         return unless has_ssl?
 
-        Gitlab::Kubernetes::Helm::Certificate
+        Gitlab::Kubernetes::Helm::V2::Certificate
           .from_strings(ca_key, ca_cert)
       end
     end

app/models/clusters/applications/ingress.rb

@@ -62,7 +62,7 @@ module Clusters
       end
 
       def install_command
-        Gitlab::Kubernetes::Helm::InstallCommand.new(
+        helm_command_module::InstallCommand.new(
           name: name,
           repository: repository,
           version: VERSION,

app/models/clusters/applications/jupyter.rb

@@ -39,7 +39,7 @@ module Clusters
       end
 
       def install_command
-        Gitlab::Kubernetes::Helm::InstallCommand.new(
+        helm_command_module::InstallCommand.new(
           name: name,
           version: VERSION,
           rbac: cluster.platform_kubernetes_rbac?,

app/models/clusters/applications/knative.rb

@@ -70,7 +70,7 @@ module Clusters
       end
 
       def install_command
-        Gitlab::Kubernetes::Helm::InstallCommand.new(
+        helm_command_module::InstallCommand.new(
           name: name,
           version: VERSION,
           rbac: cluster.platform_kubernetes_rbac?,
@@ -94,7 +94,7 @@ module Clusters
       end
 
       def uninstall_command
-        Gitlab::Kubernetes::Helm::DeleteCommand.new(
+        helm_command_module::DeleteCommand.new(
           name: name,
           rbac: cluster.platform_kubernetes_rbac?,
           files: files,

app/models/clusters/applications/prometheus.rb

@@ -67,7 +67,7 @@ module Clusters
       end
 
       def install_command
-        Gitlab::Kubernetes::Helm::InstallCommand.new(
+        helm_command_module::InstallCommand.new(
           name: name,
           repository: repository,
           version: VERSION,
@@ -79,7 +79,7 @@ module Clusters
       end
 
       def patch_command(values)
-        ::Gitlab::Kubernetes::Helm::PatchCommand.new(
+        helm_command_module::PatchCommand.new(
           name: name,
           repository: repository,
           version: version,
@@ -90,7 +90,7 @@ module Clusters
       end
 
       def uninstall_command
-        Gitlab::Kubernetes::Helm::DeleteCommand.new(
+        helm_command_module::DeleteCommand.new(
           name: name,
           rbac: cluster.platform_kubernetes_rbac?,
           files: files,

app/models/clusters/applications/runner.rb

@@ -30,7 +30,7 @@ module Clusters
       end
 
       def install_command
-        Gitlab::Kubernetes::Helm::InstallCommand.new(
+        helm_command_module::InstallCommand.new(
           name: name,
           version: VERSION,
           rbac: cluster.platform_kubernetes_rbac?,

app/models/clusters/cluster.rb

@@ -79,6 +79,9 @@ module Clusters
     validates :cluster_type, presence: true
     validates :domain, allow_blank: true, hostname: { allow_numeric_hostname: true }
     validates :namespace_per_environment, inclusion: { in: [true, false] }
+    validates :helm_major_version, inclusion: { in: [2, 3] }
+
+    default_value_for :helm_major_version, 3
 
     validate :restrict_modification, on: :update
     validate :no_groups, unless: :group_type?

app/models/clusters/concerns/application_core.rb

@@ -12,6 +12,17 @@ module Clusters
 
         after_initialize :set_initial_status
 
+        def helm_command_module
+          case cluster.helm_major_version
+          when 3
+            Gitlab::Kubernetes::Helm::V3
+          when 2
+            Gitlab::Kubernetes::Helm::V2
+          else
+            raise "Invalid Helm major version"
+          end
+        end
+
         def set_initial_status
           return unless not_installable?
 

app/models/clusters/concerns/application_data.rb

@@ -4,7 +4,7 @@ module Clusters
   module Concerns
     module ApplicationData
       def uninstall_command
-        Gitlab::Kubernetes::Helm::DeleteCommand.new(
+        helm_command_module::DeleteCommand.new(
           name: name,
           rbac: cluster.platform_kubernetes_rbac?,
           files: files

changelogs/unreleased/add-helm3-support-for-cluster-apps.yml

+---
+title: Use Helm 3 by default for GitLab-managed apps in new clusters
+merge_request: 46267
+author:
+type: changed

db/migrate/20201028184640_add_helm_major_version_to_clusters.rb

+# frozen_string_literal: true
+
+# See https://docs.gitlab.com/ee/development/migration_style_guide.html
+# for more information on how to write migrations for GitLab.
+
+class AddHelmMajorVersionToClusters < ActiveRecord::Migration[6.0]
+  DOWNTIME = false
+
+  def change
+    add_column(:clusters, :helm_major_version, :integer, default: 2, null: false)
+  end
+end

db/schema_migrations/20201028184640

+5520cca016af07fb2e009c0e3254362f106a9cc808cbb61e280221be82be1b25
\ No newline at end of file

db/structure.sql

@@ -10967,7 +10967,8 @@ CREATE TABLE clusters (
     namespace_per_environment boolean DEFAULT true NOT NULL,
     management_project_id integer,
     cleanup_status smallint DEFAULT 1 NOT NULL,
-    cleanup_status_reason text
+    cleanup_status_reason text,
+    helm_major_version integer DEFAULT 2 NOT NULL
 );
 
 CREATE TABLE clusters_applications_cert_managers (

lib/gitlab/kubernetes/helm/base_command.rb

-# frozen_string_literal: true
-
-module Gitlab
-  module Kubernetes
-    module Helm
-      class BaseCommand
-        attr_reader :name, :files
-
-        def initialize(rbac:, name:, files:)
-          @rbac = rbac
-          @name = name
-          @files = files
-        end
-
-        def rbac?
-          @rbac
-        end
-
-        def pod_resource
-          pod_service_account_name = rbac? ? service_account_name : nil
-
-          Gitlab::Kubernetes::Helm::Pod.new(self, namespace, service_account_name: pod_service_account_name).generate
-        end
-
-        def generate_script
-          <<~HEREDOC
-            set -xeo pipefail
-          HEREDOC
-        end
-
-        def pod_name
-          "install-#{name}"
-        end
-
-        def config_map_resource
-          Gitlab::Kubernetes::ConfigMap.new(name, files).generate
-        end
-
-        def service_account_resource
-          return unless rbac?
-
-          Gitlab::Kubernetes::ServiceAccount.new(service_account_name, namespace).generate
-        end
-
-        def cluster_role_binding_resource
-          return unless rbac?
-
-          subjects = [{ kind: 'ServiceAccount', name: service_account_name, namespace: namespace }]
-
-          Gitlab::Kubernetes::ClusterRoleBinding.new(
-            cluster_role_binding_name,
-            cluster_role_name,
-            subjects
-          ).generate
-        end
-
-        def file_names
-          files.keys
-        end
-
-        private
-
-        def files_dir
-          "/data/helm/#{name}/config"
-        end
-
-        def namespace
-          Gitlab::Kubernetes::Helm::NAMESPACE
-        end
-
-        def service_account_name
-          Gitlab::Kubernetes::Helm::SERVICE_ACCOUNT
-        end
-
-        def cluster_role_binding_name
-          Gitlab::Kubernetes::Helm::CLUSTER_ROLE_BINDING
-        end
-
-        def cluster_role_name
-          Gitlab::Kubernetes::Helm::CLUSTER_ROLE
-        end
-      end
-    end
-  end
-end

lib/gitlab/kubernetes/helm/certificate.rb

-# frozen_string_literal: true
-module Gitlab
-  module Kubernetes
-    module Helm
-      class Certificate
-        INFINITE_EXPIRY = 1000.years
-        SHORT_EXPIRY = 30.minutes
-
-        attr_reader :key, :cert
-
-        def key_string
-          @key.to_s
-        end
-
-        def cert_string
-          @cert.to_pem
-        end
-
-        def self.from_strings(key_string, cert_string)
-          key = OpenSSL::PKey::RSA.new(key_string)
-          cert = OpenSSL::X509::Certificate.new(cert_string)
-          new(key, cert)
-        end
-
-        def self.generate_root
-          _issue(signed_by: nil, expires_in: INFINITE_EXPIRY, certificate_authority: true)
-        end
-
-        def issue(expires_in: SHORT_EXPIRY)
-          self.class._issue(signed_by: self, expires_in: expires_in, certificate_authority: false)
-        end
-
-        private
-
-        def self._issue(signed_by:, expires_in:, certificate_authority:)
-          key = OpenSSL::PKey::RSA.new(4096)
-          public_key = key.public_key
-
-          subject = OpenSSL::X509::Name.parse("/C=US")
-
-          cert = OpenSSL::X509::Certificate.new
-          cert.subject = subject
-
-          cert.issuer = signed_by&.cert&.subject || subject
-
-          cert.not_before = Time.now
-          cert.not_after = expires_in.from_now
-          cert.public_key = public_key
-          cert.serial = 0x0
-          cert.version = 2
-
-          if certificate_authority
-            extension_factory = OpenSSL::X509::ExtensionFactory.new
-            extension_factory.subject_certificate = cert
-            extension_factory.issuer_certificate = cert
-            cert.add_extension(extension_factory.create_extension('subjectKeyIdentifier', 'hash'))
-            cert.add_extension(extension_factory.create_extension('basicConstraints', 'CA:TRUE', true))
-            cert.add_extension(extension_factory.create_extension('keyUsage', 'cRLSign,keyCertSign', true))
-          end
-
-          cert.sign(signed_by&.key || key, OpenSSL::Digest::SHA256.new)
-
-          new(key, cert)
-        end
-
-        def initialize(key, cert)
-          @key = key
-          @cert = cert
-        end
-      end
-    end
-  end
-end

lib/gitlab/kubernetes/helm/client_command.rb

-# frozen_string_literal: true
-
-module Gitlab
-  module Kubernetes
-    module Helm
-      module ClientCommand
-        def init_command
-          <<~SHELL.chomp
-            export HELM_HOST="localhost:44134"
-            tiller -listen ${HELM_HOST} -alsologtostderr &
-            helm init --client-only
-          SHELL
-        end
-
-        def repository_command
-          ['helm', 'repo', 'add', name, repository].shelljoin if repository
-        end
-
-        private
-
-        def repository_update_command
-          'helm repo update'
-        end
-
-        def optional_tls_flags
-          return [] unless files.key?(:'ca.pem')
-
-          [
-            '--tls',
-            '--tls-ca-cert', "#{files_dir}/ca.pem",
-            '--tls-cert', "#{files_dir}/cert.pem",
-            '--tls-key', "#{files_dir}/key.pem"
-          ]
-        end
-      end
-    end
-  end
-end

lib/gitlab/kubernetes/helm/delete_command.rb

-# frozen_string_literal: true
-
-module Gitlab
-  module Kubernetes
-    module Helm
-      class DeleteCommand < BaseCommand
-        include ClientCommand
-
-        attr_reader :predelete, :postdelete
-
-        def initialize(predelete: nil, postdelete: nil, **args)
-          super(**args)
-          @predelete = predelete
-          @postdelete = postdelete
-        end
-
-        def generate_script
-          super + [
-            init_command,
-            predelete,
-            delete_command,
-            postdelete
-          ].compact.join("\n")
-        end
-
-        def pod_name
-          "uninstall-#{name}"
-        end
-
-        def delete_command
-          ['helm', 'delete', '--purge', name].shelljoin
-        end
-      end
-    end
-  end
-end

lib/gitlab/kubernetes/helm/init_command.rb

-# frozen_string_literal: true
-
-module Gitlab
-  module Kubernetes
-    module Helm
-      class InitCommand < BaseCommand
-        def generate_script
-          super + [
-            init_helm_command
-          ].join("\n")
-        end
-
-        private
-
-        def init_helm_command
-          command = %w[helm init] + init_command_flags
-
-          command.shelljoin
-        end
-
-        def init_command_flags
-          tls_flags + optional_service_account_flag
-        end
-
-        def tls_flags
-          [
-            '--tiller-tls',
-            '--tiller-tls-verify',
-            '--tls-ca-cert', "#{files_dir}/ca.pem",
-            '--tiller-tls-cert', "#{files_dir}/cert.pem",
-            '--tiller-tls-key', "#{files_dir}/key.pem"
-          ]
-        end
-
-        def optional_service_account_flag
-          return [] unless rbac?
-
-          ['--service-account', service_account_name]
-        end
-      end
-    end
-  end
-end

lib/gitlab/kubernetes/helm/install_command.rb

-# frozen_string_literal: true
-
-module Gitlab
-  module Kubernetes
-    module Helm
-      class InstallCommand < BaseCommand
-        include ClientCommand
-
-        attr_reader :chart, :repository, :preinstall, :postinstall
-        attr_accessor :version
-
-        def initialize(chart:, version: nil, repository: nil, preinstall: nil, postinstall: nil, **args)
-          super(**args)
-          @chart = chart
-          @version = version
-          @repository = repository
-          @preinstall = preinstall
-          @postinstall = postinstall
-        end
-
-        def generate_script
-          super + [
-            init_command,
-            repository_command,
-            repository_update_command,
-            preinstall,
-            install_command,
-            postinstall
-          ].compact.join("\n")
-        end
-
-        private
-
-        # Uses `helm upgrade --install` which means we can use this for both
-        # installation and uprade of applications
-        def install_command
-          command = ['helm', 'upgrade', name, chart] +
-            install_flag +
-            rollback_support_flag +
-            reset_values_flag +
-            optional_version_flag +
-            rbac_create_flag +
-            namespace_flag +
-            value_flag
-
-          command.shelljoin
-        end
-
-        def install_flag
-          ['--install']
-        end
-
-        def reset_values_flag
-          ['--reset-values']
-        end
-
-        def value_flag
-          ['-f', "/data/helm/#{name}/config/values.yaml"]
-        end
-
-        def namespace_flag
-          ['--namespace', Gitlab::Kubernetes::Helm::NAMESPACE]
-        end
-
-        def rbac_create_flag
-          if rbac?
-            %w[--set rbac.create=true,rbac.enabled=true]
-          else
-            %w[--set rbac.create=false,rbac.enabled=false]
-          end
-        end
-
-        def optional_version_flag
-          return [] unless version
-
-          ['--version', version]
-        end
-
-        def rollback_support_flag
-          ['--atomic', '--cleanup-on-fail']
-        end
-      end
-    end
-  end
-end

lib/gitlab/kubernetes/helm/patch_command.rb

-# frozen_string_literal: true
-
-# PatchCommand is for updating values in installed charts without overwriting
-# existing values.
-module Gitlab
-  module Kubernetes
-    module Helm
-      class PatchCommand < BaseCommand
-        include ClientCommand
-
-        attr_reader :chart, :repository
-        attr_accessor :version
-
-        def initialize(chart:, version:, repository: nil, **args)
-          super(**args)
-
-          # version is mandatory to prevent chart mismatches
-          # we do not want our values interpreted in the context of the wrong version
-          raise ArgumentError, 'version is required' if version.blank?
-
-          @chart = chart
-          @version = version
-          @repository = repository
-        end
-
-        def generate_script
-          super + [
-            init_command,
-            repository_command,
-            repository_update_command,
-            upgrade_command
-          ].compact.join("\n")
-        end
-
-        private
-
-        def upgrade_command
-          command = ['helm', 'upgrade', name, chart] +
-            reuse_values_flag +
-            version_flag +
-            namespace_flag +
-            value_flag
-
-          command.shelljoin
-        end
-
-        def reuse_values_flag
-          ['--reuse-values']
-        end
-
-        def value_flag
-          ['-f', "/data/helm/#{name}/config/values.yaml"]
-        end
-
-        def namespace_flag
-          ['--namespace', Gitlab::Kubernetes::Helm::NAMESPACE]
-        end
-
-        def version_flag
-          ['--version', version]
-        end
-      end
-    end
-  end
-end

lib/gitlab/kubernetes/helm/pod.rb

@@ -27,7 +27,7 @@ module Gitlab
         def container_specification
           {
             name: 'helm',
-            image: "registry.gitlab.com/gitlab-org/cluster-integration/helm-install-image/releases/#{Gitlab::Kubernetes::Helm::HELM_VERSION}-kube-#{Gitlab::Kubernetes::Helm::KUBECTL_VERSION}",
+            image: "registry.gitlab.com/gitlab-org/cluster-integration/helm-install-image/releases/#{command.class::HELM_VERSION}-kube-#{Gitlab::Kubernetes::Helm::KUBECTL_VERSION}-alpine-3.12",
             env: generate_pod_env(command),
             command: %w(/bin/sh),
             args: %w(-c $(COMMAND_SCRIPT))
@@ -50,11 +50,10 @@ module Gitlab
         end
 
         def generate_pod_env(command)
-          {
-            HELM_VERSION: Gitlab::Kubernetes::Helm::HELM_VERSION,
-            TILLER_NAMESPACE: namespace_name,
+          command.env.merge(
+            HELM_VERSION: command.class::HELM_VERSION,
             COMMAND_SCRIPT: command.generate_script
-          }.map { |key, value| { name: key, value: value } }
+          ).map { |key, value| { name: key, value: value } }
         end
 
         def volumes_specification

lib/gitlab/kubernetes/helm/reset_command.rb

-# frozen_string_literal: true
-
-module Gitlab
-  module Kubernetes
-    module Helm
-      class ResetCommand < BaseCommand
-        include ClientCommand
-
-        def generate_script
-          super + [
-            reset_helm_command,
-            delete_tiller_replicaset,
-            delete_tiller_clusterrolebinding
-          ].join("\n")
-        end
-
-        def pod_name
-          "uninstall-#{name}"
-        end
-
-        private
-
-        # This method can be delete once we upgrade Helm to > 12.13.0
-        # https://gitlab.com/gitlab-org/gitlab-foss/merge_requests/27096#note_159695900
-        #
-        # Tracking this method to be removed here:
-        # https://gitlab.com/gitlab-org/gitlab-foss/issues/52791#note_199374155
-        def delete_tiller_replicaset
-          delete_args = %w[replicaset -n gitlab-managed-apps -l name=tiller]
-
-          Gitlab::Kubernetes::KubectlCmd.delete(*delete_args)
-        end
-
-        def delete_tiller_clusterrolebinding
-          delete_args = %w[clusterrolebinding tiller-admin]
-
-          Gitlab::Kubernetes::KubectlCmd.delete(*delete_args)
-        end
-
-        def reset_helm_command
-          command = %w[helm reset] + optional_tls_flags
-
-          command.shelljoin
-        end
-      end
-    end
-  end
-end

lib/gitlab/kubernetes/helm/v2/base_command.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Kubernetes
+    module Helm
+      module V2
+        class BaseCommand
+          attr_reader :name, :files
+
+          HELM_VERSION = '2.16.9'
+
+          def initialize(rbac:, name:, files:)
+            @rbac = rbac
+            @name = name
+            @files = files
+          end
+
+          def env
+            { TILLER_NAMESPACE: namespace }
+          end
+
+          def rbac?
+            @rbac
+          end
+
+          def pod_resource
+            pod_service_account_name = rbac? ? service_account_name : nil
+
+            Gitlab::Kubernetes::Helm::Pod.new(self, namespace, service_account_name: pod_service_account_name).generate
+          end
+
+          def generate_script
+            <<~HEREDOC
+              set -xeo pipefail
+            HEREDOC
+          end
+
+          def pod_name
+            "install-#{name}"
+          end
+
+          def config_map_resource
+            Gitlab::Kubernetes::ConfigMap.new(name, files).generate
+          end
+
+          def service_account_resource
+            return unless rbac?
+
+            Gitlab::Kubernetes::ServiceAccount.new(service_account_name, namespace).generate
+          end
+
+          def cluster_role_binding_resource
+            return unless rbac?
+
+            subjects = [{ kind: 'ServiceAccount', name: service_account_name, namespace: namespace }]
+
+            Gitlab::Kubernetes::ClusterRoleBinding.new(
+              cluster_role_binding_name,
+              cluster_role_name,
+              subjects
+            ).generate
+          end
+
+          def file_names
+            files.keys
+          end
+
+          private
+
+          def files_dir
+            "/data/helm/#{name}/config"
+          end
+
+          def namespace
+            Gitlab::Kubernetes::Helm::NAMESPACE
+          end
+
+          def service_account_name
+            Gitlab::Kubernetes::Helm::SERVICE_ACCOUNT
+          end
+
+          def cluster_role_binding_name
+            Gitlab::Kubernetes::Helm::CLUSTER_ROLE_BINDING
+          end
+
+          def cluster_role_name
+            Gitlab::Kubernetes::Helm::CLUSTER_ROLE
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/kubernetes/helm/v2/certificate.rb

+# frozen_string_literal: true
+module Gitlab
+  module Kubernetes
+    module Helm
+      module V2
+        class Certificate
+          INFINITE_EXPIRY = 1000.years
+          SHORT_EXPIRY = 30.minutes
+
+          attr_reader :key, :cert
+
+          def key_string
+            @key.to_s
+          end
+
+          def cert_string
+            @cert.to_pem
+          end
+
+          def self.from_strings(key_string, cert_string)
+            key = OpenSSL::PKey::RSA.new(key_string)
+            cert = OpenSSL::X509::Certificate.new(cert_string)
+            new(key, cert)
+          end
+
+          def self.generate_root
+            _issue(signed_by: nil, expires_in: INFINITE_EXPIRY, certificate_authority: true)
+          end
+
+          def issue(expires_in: SHORT_EXPIRY)
+            self.class._issue(signed_by: self, expires_in: expires_in, certificate_authority: false)
+          end
+
+          private
+
+          def self._issue(signed_by:, expires_in:, certificate_authority:)
+            key = OpenSSL::PKey::RSA.new(4096)
+            public_key = key.public_key
+
+            subject = OpenSSL::X509::Name.parse("/C=US")
+
+            cert = OpenSSL::X509::Certificate.new
+            cert.subject = subject
+
+            cert.issuer = signed_by&.cert&.subject || subject
+
+            cert.not_before = Time.now.utc
+            cert.not_after = expires_in.from_now.utc
+            cert.public_key = public_key
+            cert.serial = 0x0
+            cert.version = 2
+
+            if certificate_authority
+              extension_factory = OpenSSL::X509::ExtensionFactory.new
+              extension_factory.subject_certificate = cert
+              extension_factory.issuer_certificate = cert
+              cert.add_extension(extension_factory.create_extension('subjectKeyIdentifier', 'hash'))
+              cert.add_extension(extension_factory.create_extension('basicConstraints', 'CA:TRUE', true))
+              cert.add_extension(extension_factory.create_extension('keyUsage', 'cRLSign,keyCertSign', true))
+            end
+
+            cert.sign(signed_by&.key || key, OpenSSL::Digest::SHA256.new)
+
+            new(key, cert)
+          end
+
+          def initialize(key, cert)
+            @key = key
+            @cert = cert
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/kubernetes/helm/v2/client_command.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Kubernetes
+    module Helm
+      module V2
+        module ClientCommand
+          def init_command
+            <<~SHELL.chomp
+              export HELM_HOST="localhost:44134"
+              tiller -listen ${HELM_HOST} -alsologtostderr &
+              helm init --client-only
+            SHELL
+          end
+
+          def repository_command
+            ['helm', 'repo', 'add', name, repository].shelljoin if repository
+          end
+
+          private
+
+          def repository_update_command
+            'helm repo update'
+          end
+
+          def optional_tls_flags
+            return [] unless files.key?(:'ca.pem')
+
+            [
+              '--tls',
+              '--tls-ca-cert', "#{files_dir}/ca.pem",
+              '--tls-cert', "#{files_dir}/cert.pem",
+              '--tls-key', "#{files_dir}/key.pem"
+            ]
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/kubernetes/helm/v2/delete_command.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Kubernetes
+    module Helm
+      module V2
+        class DeleteCommand < BaseCommand
+          include ClientCommand
+
+          attr_reader :predelete, :postdelete
+
+          def initialize(predelete: nil, postdelete: nil, **args)
+            super(**args)
+            @predelete = predelete
+            @postdelete = postdelete
+          end
+
+          def generate_script
+            super + [
+              init_command,
+              predelete,
+              delete_command,
+              postdelete
+            ].compact.join("\n")
+          end
+
+          def pod_name
+            "uninstall-#{name}"
+          end
+
+          def delete_command
+            ['helm', 'delete', '--purge', name].shelljoin
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/kubernetes/helm/v2/init_command.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Kubernetes
+    module Helm
+      module V2
+        class InitCommand < BaseCommand
+          def generate_script
+            super + [
+              init_helm_command
+            ].join("\n")
+          end
+
+          private
+
+          def init_helm_command
+            command = %w[helm init] + init_command_flags
+
+            command.shelljoin
+          end
+
+          def init_command_flags
+            tls_flags + optional_service_account_flag
+          end
+
+          def tls_flags
+            [
+              '--tiller-tls',
+              '--tiller-tls-verify',
+              '--tls-ca-cert', "#{files_dir}/ca.pem",
+              '--tiller-tls-cert', "#{files_dir}/cert.pem",
+              '--tiller-tls-key', "#{files_dir}/key.pem"
+            ]
+          end
+
+          def optional_service_account_flag
+            return [] unless rbac?
+
+            ['--service-account', service_account_name]
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/kubernetes/helm/v2/install_command.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Kubernetes
+    module Helm
+      module V2
+        class InstallCommand < BaseCommand
+          include ClientCommand
+
+          attr_reader :chart, :repository, :preinstall, :postinstall
+          attr_accessor :version
+
+          def initialize(chart:, version: nil, repository: nil, preinstall: nil, postinstall: nil, **args)
+            super(**args)
+            @chart = chart
+            @version = version
+            @repository = repository
+            @preinstall = preinstall
+            @postinstall = postinstall
+          end
+
+          def generate_script
+            super + [
+              init_command,
+              repository_command,
+              repository_update_command,
+              preinstall,
+              install_command,
+              postinstall
+            ].compact.join("\n")
+          end
+
+          private
+
+          # Uses `helm upgrade --install` which means we can use this for both
+          # installation and uprade of applications
+          def install_command
+            command = ['helm', 'upgrade', name, chart] +
+                      install_flag +
+                      rollback_support_flag +
+                      reset_values_flag +
+                      optional_version_flag +
+                      rbac_create_flag +
+                      namespace_flag +
+                      value_flag
+
+            command.shelljoin
+          end
+
+          def install_flag
+            ['--install']
+          end
+
+          def reset_values_flag
+            ['--reset-values']
+          end
+
+          def value_flag
+            ['-f', "/data/helm/#{name}/config/values.yaml"]
+          end
+
+          def namespace_flag
+            ['--namespace', Gitlab::Kubernetes::Helm::NAMESPACE]
+          end
+
+          def rbac_create_flag
+            if rbac?
+              %w[--set rbac.create=true,rbac.enabled=true]
+            else
+              %w[--set rbac.create=false,rbac.enabled=false]
+            end
+          end
+
+          def optional_version_flag
+            return [] unless version
+
+            ['--version', version]
+          end
+
+          def rollback_support_flag
+            ['--atomic', '--cleanup-on-fail']
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/kubernetes/helm/v2/patch_command.rb

+# frozen_string_literal: true
+
+# PatchCommand is for updating values in installed charts without overwriting
+# existing values.
+module Gitlab
+  module Kubernetes
+    module Helm
+      module V2
+        class PatchCommand < BaseCommand
+          include ClientCommand
+
+          attr_reader :chart, :repository
+          attr_accessor :version
+
+          def initialize(chart:, version:, repository: nil, **args)
+            super(**args)
+
+            # version is mandatory to prevent chart mismatches
+            # we do not want our values interpreted in the context of the wrong version
+            raise ArgumentError, 'version is required' if version.blank?
+
+            @chart = chart
+            @version = version
+            @repository = repository
+          end
+
+          def generate_script
+            super + [
+              init_command,
+              repository_command,
+              repository_update_command,
+              upgrade_command
+            ].compact.join("\n")
+          end
+
+          private
+
+          def upgrade_command
+            command = ['helm', 'upgrade', name, chart] +
+                      reuse_values_flag +
+                      version_flag +
+                      namespace_flag +
+                      value_flag
+
+            command.shelljoin
+          end
+
+          def reuse_values_flag
+            ['--reuse-values']
+          end
+
+          def value_flag
+            ['-f', "/data/helm/#{name}/config/values.yaml"]
+          end
+
+          def namespace_flag
+            ['--namespace', Gitlab::Kubernetes::Helm::NAMESPACE]
+          end
+
+          def version_flag
+            ['--version', version]
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/kubernetes/helm/v2/reset_command.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Kubernetes
+    module Helm
+      module V2
+        class ResetCommand < BaseCommand
+          include ClientCommand
+
+          def generate_script
+            super + [
+              reset_helm_command,
+              delete_tiller_replicaset,
+              delete_tiller_clusterrolebinding
+            ].join("\n")
+          end
+
+          def pod_name
+            "uninstall-#{name}"
+          end
+
+          private
+
+          # This method can be delete once we upgrade Helm to > 12.13.0
+          # https://gitlab.com/gitlab-org/gitlab-foss/merge_requests/27096#note_159695900
+          #
+          # Tracking this method to be removed here:
+          # https://gitlab.com/gitlab-org/gitlab-foss/issues/52791#note_199374155
+          def delete_tiller_replicaset
+            delete_args = %w[replicaset -n gitlab-managed-apps -l name=tiller]
+
+            Gitlab::Kubernetes::KubectlCmd.delete(*delete_args)
+          end
+
+          def delete_tiller_clusterrolebinding
+            delete_args = %w[clusterrolebinding tiller-admin]
+
+            Gitlab::Kubernetes::KubectlCmd.delete(*delete_args)
+          end
+
+          def reset_helm_command
+            command = %w[helm reset] + optional_tls_flags
+
+            command.shelljoin
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/kubernetes/helm/v3/base_command.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Kubernetes
+    module Helm
+      module V3
+        class BaseCommand
+          attr_reader :name, :files
+
+          HELM_VERSION = '3.2.4'
+
+          def initialize(rbac:, name:, files:)
+            @rbac = rbac
+            @name = name
+            @files = files
+          end
+
+          def env
+            {}
+          end
+
+          def rbac?
+            @rbac
+          end
+
+          def pod_resource
+            pod_service_account_name = rbac? ? service_account_name : nil
+
+            Gitlab::Kubernetes::Helm::Pod.new(self, namespace, service_account_name: pod_service_account_name).generate
+          end
+
+          def generate_script
+            <<~HEREDOC
+              set -xeo pipefail
+            HEREDOC
+          end
+
+          def pod_name
+            "install-#{name}"
+          end
+
+          def config_map_resource
+            Gitlab::Kubernetes::ConfigMap.new(name, files).generate
+          end
+
+          def service_account_resource
+            return unless rbac?
+
+            Gitlab::Kubernetes::ServiceAccount.new(service_account_name, namespace).generate
+          end
+
+          def cluster_role_binding_resource
+            return unless rbac?
+
+            subjects = [{ kind: 'ServiceAccount', name: service_account_name, namespace: namespace }]
+
+            Gitlab::Kubernetes::ClusterRoleBinding.new(
+              cluster_role_binding_name,
+              cluster_role_name,
+              subjects
+            ).generate
+          end
+
+          def file_names
+            files.keys
+          end
+
+          def repository_command
+            ['helm', 'repo', 'add', name, repository].shelljoin if repository
+          end
+
+          private
+
+          def repository_update_command
+            'helm repo update'
+          end
+
+          def namespace_flag
+            ['--namespace', Gitlab::Kubernetes::Helm::NAMESPACE]
+          end
+
+          def namespace
+            Gitlab::Kubernetes::Helm::NAMESPACE
+          end
+
+          def service_account_name
+            Gitlab::Kubernetes::Helm::SERVICE_ACCOUNT
+          end
+
+          def cluster_role_binding_name
+            Gitlab::Kubernetes::Helm::CLUSTER_ROLE_BINDING
+          end
+
+          def cluster_role_name
+            Gitlab::Kubernetes::Helm::CLUSTER_ROLE
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/kubernetes/helm/v3/delete_command.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Kubernetes
+    module Helm
+      module V3
+        class DeleteCommand < BaseCommand
+          attr_reader :predelete, :postdelete
+
+          def initialize(predelete: nil, postdelete: nil, **args)
+            super(**args)
+            @predelete = predelete
+            @postdelete = postdelete
+          end
+
+          def generate_script
+            super + [
+              predelete,
+              delete_command,
+              postdelete
+            ].compact.join("\n")
+          end
+
+          def pod_name
+            "uninstall-#{name}"
+          end
+
+          def delete_command
+            ['helm', 'uninstall', name, *namespace_flag].shelljoin
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/kubernetes/helm/v3/install_command.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Kubernetes
+    module Helm
+      module V3
+        class InstallCommand < BaseCommand
+          attr_reader :chart, :repository, :preinstall, :postinstall
+          attr_accessor :version
+
+          def initialize(chart:, version: nil, repository: nil, preinstall: nil, postinstall: nil, **args)
+            super(**args)
+            @chart = chart
+            @version = version
+            @repository = repository
+            @preinstall = preinstall
+            @postinstall = postinstall
+          end
+
+          def generate_script
+            super + [
+              repository_command,
+              repository_update_command,
+              preinstall,
+              install_command,
+              postinstall
+            ].compact.join("\n")
+          end
+
+          private
+
+          # Uses `helm upgrade --install` which means we can use this for both
+          # installation and uprade of applications
+          def install_command
+            command = ['helm', 'upgrade', name, chart] +
+                      install_flag +
+                      rollback_support_flag +
+                      reset_values_flag +
+                      optional_version_flag +
+                      rbac_create_flag +
+                      namespace_flag +
+                      value_flag
+
+            command.shelljoin
+          end
+
+          def install_flag
+            ['--install']
+          end
+
+          def reset_values_flag
+            ['--reset-values']
+          end
+
+          def value_flag
+            ['-f', "/data/helm/#{name}/config/values.yaml"]
+          end
+
+          def rbac_create_flag
+            if rbac?
+              %w[--set rbac.create=true,rbac.enabled=true]
+            else
+              %w[--set rbac.create=false,rbac.enabled=false]
+            end
+          end
+
+          def optional_version_flag
+            return [] unless version
+
+            ['--version', version]
+          end
+
+          def rollback_support_flag
+            ['--atomic', '--cleanup-on-fail']
+          end
+        end
+      end
+    end
+  end
+end

lib/gitlab/kubernetes/helm/v3/patch_command.rb

+# frozen_string_literal: true
+
+# PatchCommand is for updating values in installed charts without overwriting
+# existing values.
+module Gitlab
+  module Kubernetes
+    module Helm
+      module V3
+        class PatchCommand < BaseCommand
+          attr_reader :chart, :repository
+          attr_accessor :version
+
+          def initialize(chart:, version:, repository: nil, **args)
+            super(**args)
+
+            # version is mandatory to prevent chart mismatches
+            # we do not want our values interpreted in the context of the wrong version
+            raise ArgumentError, 'version is required' if version.blank?
+
+            @chart = chart
+            @version = version
+            @repository = repository
+          end
+
+          def generate_script
+            super + [
+              repository_command,
+              repository_update_command,
+              upgrade_command
+            ].compact.join("\n")
+          end
+
+          private
+
+          def upgrade_command
+            command = ['helm', 'upgrade', name, chart] +
+                      reuse_values_flag +
+                      version_flag +
+                      namespace_flag +
+                      value_flag
+
+            command.shelljoin
+          end
+
+          def reuse_values_flag
+            ['--reuse-values']
+          end
+
+          def value_flag
+            ['-f', "/data/helm/#{name}/config/values.yaml"]
+          end
+
+          def version_flag
+            ['--version', version]
+          end
+        end
+      end
+    end
+  end
+end

spec/factories/clusters/applications/helm.rb

@@ -5,7 +5,7 @@ FactoryBot.define do
     cluster factory: %i(cluster provided_by_gcp)
 
     before(:create) do
-      allow(Gitlab::Kubernetes::Helm::Certificate).to receive(:generate_root)
+      allow(Gitlab::Kubernetes::Helm::V2::Certificate).to receive(:generate_root)
         .and_return(
           double(
             key_string: File.read(Rails.root.join('spec/fixtures/clusters/sample_key.key')),
@@ -15,7 +15,7 @@ FactoryBot.define do
     end
 
     after(:create) do
-      allow(Gitlab::Kubernetes::Helm::Certificate).to receive(:generate_root).and_call_original
+      allow(Gitlab::Kubernetes::Helm::V2::Certificate).to receive(:generate_root).and_call_original
     end
 
     trait :not_installable do

spec/lib/gitlab/kubernetes/helm/api_spec.rb

@@ -13,7 +13,7 @@ RSpec.describe Gitlab::Kubernetes::Helm::API do
   let(:files) { {} }
 
   let(:command) do
-    Gitlab::Kubernetes::Helm::InstallCommand.new(
+    Gitlab::Kubernetes::Helm::V2::InstallCommand.new(
       name: application_name,
       chart: 'chart-name',
       rbac: rbac,
@@ -142,7 +142,7 @@ RSpec.describe Gitlab::Kubernetes::Helm::API do
     end
 
     context 'with a service account' do
-      let(:command) { Gitlab::Kubernetes::Helm::InitCommand.new(name: application_name, files: files, rbac: rbac) }
+      let(:command) { Gitlab::Kubernetes::Helm::V2::InitCommand.new(name: application_name, files: files, rbac: rbac) }
 
       context 'rbac-enabled cluster' do
         let(:rbac) { true }

spec/lib/gitlab/kubernetes/helm/pod_spec.rb

@@ -4,75 +4,84 @@ require 'spec_helper'
 
 RSpec.describe Gitlab::Kubernetes::Helm::Pod do
   describe '#generate' do
-    let(:app) { create(:clusters_applications_prometheus) }
-    let(:command) { app.install_command }
-    let(:namespace) { Gitlab::Kubernetes::Helm::NAMESPACE }
-    let(:service_account_name) { nil }
+    using RSpec::Parameterized::TableSyntax
 
-    subject { described_class.new(command, namespace, service_account_name: service_account_name) }
+    where(:helm_major_version, :expected_helm_version, :expected_command_env) do
+      2 | '2.16.9' | [:TILLER_NAMESPACE]
+      3 | '3.2.4'  | nil
+    end
 
-    context 'with a command' do
-      it 'generates a Kubeclient::Resource' do
-        expect(subject.generate).to be_a_kind_of(Kubeclient::Resource)
-      end
+    with_them do
+      let(:cluster) { create(:cluster, helm_major_version: helm_major_version) }
+      let(:app) { create(:clusters_applications_prometheus, cluster: cluster) }
+      let(:command) { app.install_command }
+      let(:namespace) { Gitlab::Kubernetes::Helm::NAMESPACE }
+      let(:service_account_name) { nil }
 
-      it 'generates the appropriate metadata' do
-        metadata = subject.generate.metadata
-        expect(metadata.name).to eq("install-#{app.name}")
-        expect(metadata.namespace).to eq('gitlab-managed-apps')
-        expect(metadata.labels['gitlab.org/action']).to eq('install')
-        expect(metadata.labels['gitlab.org/application']).to eq(app.name)
-      end
+      subject { described_class.new(command, namespace, service_account_name: service_account_name) }
 
-      it 'generates a container spec' do
-        spec = subject.generate.spec
-        expect(spec.containers.count).to eq(1)
-      end
+      context 'with a command' do
+        it 'generates a Kubeclient::Resource' do
+          expect(subject.generate).to be_a_kind_of(Kubeclient::Resource)
+        end
 
-      it 'generates the appropriate specifications for the container' do
-        container = subject.generate.spec.containers.first
-        expect(container.name).to eq('helm')
-        expect(container.image).to eq('registry.gitlab.com/gitlab-org/cluster-integration/helm-install-image/releases/2.16.9-kube-1.13.12')
-        expect(container.env.count).to eq(3)
-        expect(container.env.map(&:name)).to match_array([:HELM_VERSION, :TILLER_NAMESPACE, :COMMAND_SCRIPT])
-        expect(container.command).to match_array(["/bin/sh"])
-        expect(container.args).to match_array(["-c", "$(COMMAND_SCRIPT)"])
-      end
+        it 'generates the appropriate metadata' do
+          metadata = subject.generate.metadata
+          expect(metadata.name).to eq("install-#{app.name}")
+          expect(metadata.namespace).to eq('gitlab-managed-apps')
+          expect(metadata.labels['gitlab.org/action']).to eq('install')
+          expect(metadata.labels['gitlab.org/application']).to eq(app.name)
+        end
 
-      it 'includes a never restart policy' do
-        spec = subject.generate.spec
-        expect(spec.restartPolicy).to eq('Never')
-      end
+        it 'generates a container spec' do
+          spec = subject.generate.spec
+          expect(spec.containers.count).to eq(1)
+        end
 
-      it 'includes volumes for the container' do
-        container = subject.generate.spec.containers.first
-        expect(container.volumeMounts.first['name']).to eq('configuration-volume')
-        expect(container.volumeMounts.first['mountPath']).to eq("/data/helm/#{app.name}/config")
-      end
+        it 'generates the appropriate specifications for the container' do
+          container = subject.generate.spec.containers.first
+          expect(container.name).to eq('helm')
+          expect(container.image).to eq("registry.gitlab.com/gitlab-org/cluster-integration/helm-install-image/releases/#{expected_helm_version}-kube-1.13.12-alpine-3.12")
+          expect(container.env.map(&:name)).to include(:HELM_VERSION, :COMMAND_SCRIPT, *expected_command_env)
+          expect(container.command).to match_array(["/bin/sh"])
+          expect(container.args).to match_array(["-c", "$(COMMAND_SCRIPT)"])
+        end
 
-      it 'includes a volume inside the specification' do
-        spec = subject.generate.spec
-        expect(spec.volumes.first['name']).to eq('configuration-volume')
-      end
+        it 'includes a never restart policy' do
+          spec = subject.generate.spec
+          expect(spec.restartPolicy).to eq('Never')
+        end
 
-      it 'mounts configMap specification in the volume' do
-        volume = subject.generate.spec.volumes.first
-        expect(volume.configMap['name']).to eq("values-content-configuration-#{app.name}")
-        expect(volume.configMap['items'].first['key']).to eq(:'values.yaml')
-        expect(volume.configMap['items'].first['path']).to eq(:'values.yaml')
-      end
+        it 'includes volumes for the container' do
+          container = subject.generate.spec.containers.first
+          expect(container.volumeMounts.first['name']).to eq('configuration-volume')
+          expect(container.volumeMounts.first['mountPath']).to eq("/data/helm/#{app.name}/config")
+        end
 
-      it 'has no serviceAccountName' do
-        spec = subject.generate.spec
-        expect(spec.serviceAccountName).to be_nil
-      end
+        it 'includes a volume inside the specification' do
+          spec = subject.generate.spec
+          expect(spec.volumes.first['name']).to eq('configuration-volume')
+        end
 
-      context 'with a service_account_name' do
-        let(:service_account_name) { 'sa' }
+        it 'mounts configMap specification in the volume' do
+          volume = subject.generate.spec.volumes.first
+          expect(volume.configMap['name']).to eq("values-content-configuration-#{app.name}")
+          expect(volume.configMap['items'].first['key']).to eq(:'values.yaml')
+          expect(volume.configMap['items'].first['path']).to eq(:'values.yaml')
+        end
 
-        it 'uses the serviceAccountName provided' do
+        it 'has no serviceAccountName' do
           spec = subject.generate.spec
-          expect(spec.serviceAccountName).to eq(service_account_name)
+          expect(spec.serviceAccountName).to be_nil
+        end
+
+        context 'with a service_account_name' do
+          let(:service_account_name) { 'sa' }
+
+          it 'uses the serviceAccountName provided' do
+            spec = subject.generate.spec
+            expect(spec.serviceAccountName).to eq(service_account_name)
+          end
         end
       end
     end

spec/lib/gitlab/kubernetes/helm/v2/base_command_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Kubernetes::Helm::V2::BaseCommand do
+  subject(:base_command) do
+    test_class.new(rbac)
+  end
+
+  let(:application) { create(:clusters_applications_helm) }
+  let(:rbac) { false }
+
+  let(:test_class) do
+    Class.new(described_class) do
+      def initialize(rbac)
+        super(
+          name: 'test-class-name',
+          rbac: rbac,
+          files: { some: 'value' }
+        )
+      end
+    end
+  end
+
+  describe 'HELM_VERSION' do
+    subject { described_class::HELM_VERSION }
+
+    it { is_expected.to match /^2\.\d+\.\d+$/ }
+  end
+
+  describe '#env' do
+    subject { base_command.env }
+
+    it { is_expected.to include(TILLER_NAMESPACE: 'gitlab-managed-apps') }
+  end
+
+  it_behaves_like 'helm command generator' do
+    let(:commands) { '' }
+  end
+
+  describe '#pod_name' do
+    subject { base_command.pod_name }
+
+    it { is_expected.to eq('install-test-class-name') }
+  end
+
+  it_behaves_like 'helm command' do
+    let(:command) { base_command }
+  end
+end

spec/lib/gitlab/kubernetes/helm/certificate_spec.rb → spec/lib/gitlab/kubernetes/helm/v2/certificate_spec.rb

 # frozen_string_literal: true
 require 'spec_helper'
 
-RSpec.describe Gitlab::Kubernetes::Helm::Certificate do
+RSpec.describe Gitlab::Kubernetes::Helm::V2::Certificate do
   describe '.generate_root' do
     subject { described_class.generate_root }
 

spec/lib/gitlab/kubernetes/helm/delete_command_spec.rb → spec/lib/gitlab/kubernetes/helm/v2/delete_command_spec.rb

@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-RSpec.describe Gitlab::Kubernetes::Helm::DeleteCommand do
+RSpec.describe Gitlab::Kubernetes::Helm::V2::DeleteCommand do
   subject(:delete_command) { described_class.new(name: app_name, rbac: rbac, files: files) }
 
   let(:app_name) { 'app-name' }

spec/lib/gitlab/kubernetes/helm/init_command_spec.rb → spec/lib/gitlab/kubernetes/helm/v2/init_command_spec.rb

@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-RSpec.describe Gitlab::Kubernetes::Helm::InitCommand do
+RSpec.describe Gitlab::Kubernetes::Helm::V2::InitCommand do
   subject(:init_command) { described_class.new(name: application.name, files: files, rbac: rbac) }
 
   let(:application) { create(:clusters_applications_helm) }

spec/lib/gitlab/kubernetes/helm/install_command_spec.rb → spec/lib/gitlab/kubernetes/helm/v2/install_command_spec.rb

@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-RSpec.describe Gitlab::Kubernetes::Helm::InstallCommand do
+RSpec.describe Gitlab::Kubernetes::Helm::V2::InstallCommand do
   subject(:install_command) do
     described_class.new(
       name: 'app-name',
@@ -147,37 +147,6 @@ RSpec.describe Gitlab::Kubernetes::Helm::InstallCommand do
     end
   end
 
-  context 'when there is no ca.pem file' do
-    let(:files) { { 'file.txt': 'some content' } }
-
-    it_behaves_like 'helm command generator' do
-      let(:commands) do
-        <<~EOS
-        export HELM_HOST="localhost:44134"
-        tiller -listen ${HELM_HOST} -alsologtostderr &
-        helm init --client-only
-        helm repo add app-name https://repository.example.com
-        helm repo update
-        #{helm_install_command}
-        EOS
-      end
-
-      let(:helm_install_command) do
-        <<~EOS.squish
-        helm upgrade app-name chart-name
-           --install
-           --atomic
-           --cleanup-on-fail
-           --reset-values
-           --version 1.2.3
-           --set rbac.create\\=false,rbac.enabled\\=false
-           --namespace gitlab-managed-apps
-           -f /data/helm/app-name/config/values.yaml
-        EOS
-      end
-    end
-  end
-
   context 'when there is no version' do
     let(:version) { nil }
 

spec/lib/gitlab/kubernetes/helm/patch_command_spec.rb → spec/lib/gitlab/kubernetes/helm/v2/patch_command_spec.rb

@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-RSpec.describe Gitlab::Kubernetes::Helm::PatchCommand do
+RSpec.describe Gitlab::Kubernetes::Helm::V2::PatchCommand do
   let(:files) { { 'ca.pem': 'some file content' } }
   let(:repository) { 'https://repository.example.com' }
   let(:rbac) { false }
@@ -69,33 +69,6 @@ RSpec.describe Gitlab::Kubernetes::Helm::PatchCommand do
     end
   end
 
-  context 'when there is no ca.pem file' do
-    let(:files) { { 'file.txt': 'some content' } }
-
-    it_behaves_like 'helm command generator' do
-      let(:commands) do
-        <<~EOS
-        export HELM_HOST="localhost:44134"
-        tiller -listen ${HELM_HOST} -alsologtostderr &
-        helm init --client-only
-        helm repo add app-name https://repository.example.com
-        helm repo update
-        #{helm_upgrade_command}
-        EOS
-      end
-
-      let(:helm_upgrade_command) do
-        <<~EOS.squish
-        helm upgrade app-name chart-name
-           --reuse-values
-           --version 1.2.3
-           --namespace gitlab-managed-apps
-           -f /data/helm/app-name/config/values.yaml
-        EOS
-      end
-    end
-  end
-
   context 'when there is no version' do
     let(:version) { nil }
 

spec/lib/gitlab/kubernetes/helm/reset_command_spec.rb → spec/lib/gitlab/kubernetes/helm/v2/reset_command_spec.rb

@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-RSpec.describe Gitlab::Kubernetes::Helm::ResetCommand do
+RSpec.describe Gitlab::Kubernetes::Helm::V2::ResetCommand do
   subject(:reset_command) { described_class.new(name: name, rbac: rbac, files: files) }
 
   let(:rbac) { true }

spec/lib/gitlab/kubernetes/helm/base_command_spec.rb → spec/lib/gitlab/kubernetes/helm/v3/base_command_spec.rb

@@ -2,7 +2,7 @@
 
 require 'spec_helper'
 
-RSpec.describe Gitlab::Kubernetes::Helm::BaseCommand do
+RSpec.describe Gitlab::Kubernetes::Helm::V3::BaseCommand do
   subject(:base_command) do
     test_class.new(rbac)
   end
@@ -11,7 +11,7 @@ RSpec.describe Gitlab::Kubernetes::Helm::BaseCommand do
   let(:rbac) { false }
 
   let(:test_class) do
-    Class.new(Gitlab::Kubernetes::Helm::BaseCommand) do
+    Class.new(described_class) do
       def initialize(rbac)
         super(
           name: 'test-class-name',
@@ -22,6 +22,12 @@ RSpec.describe Gitlab::Kubernetes::Helm::BaseCommand do
     end
   end
 
+  describe 'HELM_VERSION' do
+    subject { described_class::HELM_VERSION }
+
+    it { is_expected.to match /^3\.\d+\.\d+$/ }
+  end
+
   it_behaves_like 'helm command generator' do
     let(:commands) { '' }
   end

spec/lib/gitlab/kubernetes/helm/v3/delete_command_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Kubernetes::Helm::V3::DeleteCommand do
+  subject(:delete_command) { described_class.new(name: app_name, rbac: rbac, files: files) }
+
+  let(:app_name) { 'app-name' }
+  let(:rbac) { true }
+  let(:files) { {} }
+
+  it_behaves_like 'helm command generator' do
+    let(:commands) do
+      <<~EOS
+      helm uninstall app-name --namespace gitlab-managed-apps
+      EOS
+    end
+  end
+
+  describe '#pod_name' do
+    subject { delete_command.pod_name }
+
+    it { is_expected.to eq('uninstall-app-name') }
+  end
+
+  it_behaves_like 'helm command' do
+    let(:command) { delete_command }
+  end
+
+  describe '#delete_command' do
+    it 'deletes the release' do
+      expect(subject.delete_command).to eq('helm uninstall app-name --namespace gitlab-managed-apps')
+    end
+  end
+end

spec/lib/gitlab/kubernetes/helm/v3/install_command_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Kubernetes::Helm::V3::InstallCommand do
+  subject(:install_command) do
+    described_class.new(
+      name: 'app-name',
+      chart: 'chart-name',
+      rbac: rbac,
+      files: files,
+      version: version,
+      repository: repository,
+      preinstall: preinstall,
+      postinstall: postinstall
+    )
+  end
+
+  let(:files) { { 'ca.pem': 'some file content' } }
+  let(:repository) { 'https://repository.example.com' }
+  let(:rbac) { false }
+  let(:version) { '1.2.3' }
+  let(:preinstall) { nil }
+  let(:postinstall) { nil }
+
+  it_behaves_like 'helm command generator' do
+    let(:commands) do
+      <<~EOS
+      helm repo add app-name https://repository.example.com
+      helm repo update
+      #{helm_install_comand}
+      EOS
+    end
+
+    let(:helm_install_comand) do
+      <<~EOS.squish
+      helm upgrade app-name chart-name
+        --install
+        --atomic
+        --cleanup-on-fail
+        --reset-values
+        --version 1.2.3
+        --set rbac.create\\=false,rbac.enabled\\=false
+        --namespace gitlab-managed-apps
+        -f /data/helm/app-name/config/values.yaml
+      EOS
+    end
+  end
+
+  context 'when rbac is true' do
+    let(:rbac) { true }
+
+    it_behaves_like 'helm command generator' do
+      let(:commands) do
+        <<~EOS
+        helm repo add app-name https://repository.example.com
+        helm repo update
+        #{helm_install_command}
+        EOS
+      end
+
+      let(:helm_install_command) do
+        <<~EOS.squish
+        helm upgrade app-name chart-name
+          --install
+          --atomic
+          --cleanup-on-fail
+          --reset-values
+          --version 1.2.3
+          --set rbac.create\\=true,rbac.enabled\\=true
+          --namespace gitlab-managed-apps
+          -f /data/helm/app-name/config/values.yaml
+        EOS
+      end
+    end
+  end
+
+  context 'when there is a pre-install script' do
+    let(:preinstall) { ['/bin/date', '/bin/true'] }
+
+    it_behaves_like 'helm command generator' do
+      let(:commands) do
+        <<~EOS
+        helm repo add app-name https://repository.example.com
+        helm repo update
+        /bin/date
+        /bin/true
+        #{helm_install_command}
+        EOS
+      end
+
+      let(:helm_install_command) do
+        <<~EOS.squish
+        helm upgrade app-name chart-name
+          --install
+          --atomic
+          --cleanup-on-fail
+          --reset-values
+          --version 1.2.3
+          --set rbac.create\\=false,rbac.enabled\\=false
+          --namespace gitlab-managed-apps
+          -f /data/helm/app-name/config/values.yaml
+        EOS
+      end
+    end
+  end
+
+  context 'when there is a post-install script' do
+    let(:postinstall) { ['/bin/date', "/bin/false\n"] }
+
+    it_behaves_like 'helm command generator' do
+      let(:commands) do
+        <<~EOS
+        helm repo add app-name https://repository.example.com
+        helm repo update
+        #{helm_install_command}
+        /bin/date
+        /bin/false
+        EOS
+      end
+
+      let(:helm_install_command) do
+        <<~EOS.squish
+        helm upgrade app-name chart-name
+          --install
+          --atomic
+          --cleanup-on-fail
+          --reset-values
+          --version 1.2.3
+          --set rbac.create\\=false,rbac.enabled\\=false
+          --namespace gitlab-managed-apps
+          -f /data/helm/app-name/config/values.yaml
+        EOS
+      end
+    end
+  end
+
+  context 'when there is no version' do
+    let(:version) { nil }
+
+    it_behaves_like 'helm command generator' do
+      let(:commands) do
+        <<~EOS
+        helm repo add app-name https://repository.example.com
+        helm repo update
+        #{helm_install_command}
+        EOS
+      end
+
+      let(:helm_install_command) do
+        <<~EOS.squish
+        helm upgrade app-name chart-name
+          --install
+          --atomic
+          --cleanup-on-fail
+          --reset-values
+          --set rbac.create\\=false,rbac.enabled\\=false
+          --namespace gitlab-managed-apps
+          -f /data/helm/app-name/config/values.yaml
+        EOS
+      end
+    end
+  end
+
+  it_behaves_like 'helm command' do
+    let(:command) { install_command }
+  end
+end

spec/lib/gitlab/kubernetes/helm/v3/patch_command_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Kubernetes::Helm::V3::PatchCommand do
+  let(:files) { { 'ca.pem': 'some file content' } }
+  let(:repository) { 'https://repository.example.com' }
+  let(:rbac) { false }
+  let(:version) { '1.2.3' }
+
+  subject(:patch_command) do
+    described_class.new(
+      name: 'app-name',
+      chart: 'chart-name',
+      rbac: rbac,
+      files: files,
+      version: version,
+      repository: repository
+    )
+  end
+
+  it_behaves_like 'helm command generator' do
+    let(:commands) do
+      <<~EOS
+      helm repo add app-name https://repository.example.com
+      helm repo update
+      #{helm_upgrade_comand}
+      EOS
+    end
+
+    let(:helm_upgrade_comand) do
+      <<~EOS.squish
+      helm upgrade app-name chart-name
+        --reuse-values
+        --version 1.2.3
+        --namespace gitlab-managed-apps
+        -f /data/helm/app-name/config/values.yaml
+      EOS
+    end
+  end
+
+  context 'when rbac is true' do
+    let(:rbac) { true }
+
+    it_behaves_like 'helm command generator' do
+      let(:commands) do
+        <<~EOS
+        helm repo add app-name https://repository.example.com
+        helm repo update
+        #{helm_upgrade_command}
+        EOS
+      end
+
+      let(:helm_upgrade_command) do
+        <<~EOS.squish
+        helm upgrade app-name chart-name
+          --reuse-values
+          --version 1.2.3
+          --namespace gitlab-managed-apps
+          -f /data/helm/app-name/config/values.yaml
+        EOS
+      end
+    end
+  end
+
+  context 'when there is no version' do
+    let(:version) { nil }
+
+    it { expect { patch_command }.to raise_error(ArgumentError, 'version is required') }
+  end
+
+  describe '#pod_name' do
+    subject { patch_command.pod_name }
+
+    it { is_expected.to eq 'install-app-name' }
+  end
+
+  it_behaves_like 'helm command' do
+    let(:command) { patch_command }
+  end
+end

spec/models/clusters/applications/cert_manager_spec.rb

@@ -40,7 +40,7 @@ RSpec.describe Clusters::Applications::CertManager do
 
     subject { cert_manager.install_command }
 
-    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::InstallCommand) }
+    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::V3::InstallCommand) }
 
     it 'is initialized with cert_manager arguments' do
       expect(subject.name).to eq('certmanager')
@@ -90,7 +90,7 @@ RSpec.describe Clusters::Applications::CertManager do
   describe '#uninstall_command' do
     subject { cert_manager.uninstall_command }
 
-    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::DeleteCommand) }
+    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::V3::DeleteCommand) }
 
     it 'is initialized with cert_manager arguments' do
       expect(subject.name).to eq('certmanager')

spec/models/clusters/applications/crossplane_spec.rb

@@ -25,7 +25,7 @@ RSpec.describe Clusters::Applications::Crossplane do
 
     subject { crossplane.install_command }
 
-    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::InstallCommand) }
+    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::V3::InstallCommand) }
 
     it 'is initialized with crossplane arguments' do
       expect(subject.name).to eq('crossplane')

spec/models/clusters/applications/elastic_stack_spec.rb

@@ -15,7 +15,7 @@ RSpec.describe Clusters::Applications::ElasticStack do
 
     subject { elastic_stack.install_command }
 
-    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::InstallCommand) }
+    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::V3::InstallCommand) }
 
     it 'is initialized with elastic stack arguments' do
       expect(subject.name).to eq('elastic-stack')
@@ -57,7 +57,7 @@ RSpec.describe Clusters::Applications::ElasticStack do
 
       it 'includes a preinstall script' do
         expect(subject.preinstall).not_to be_empty
-        expect(subject.preinstall.first).to include("delete")
+        expect(subject.preinstall.first).to include("helm uninstall")
       end
     end
 
@@ -69,7 +69,7 @@ RSpec.describe Clusters::Applications::ElasticStack do
 
       it 'includes a preinstall script' do
         expect(subject.preinstall).not_to be_empty
-        expect(subject.preinstall.first).to include("delete")
+        expect(subject.preinstall.first).to include("helm uninstall")
       end
     end
 
@@ -123,7 +123,7 @@ RSpec.describe Clusters::Applications::ElasticStack do
 
     subject { elastic_stack.uninstall_command }
 
-    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::DeleteCommand) }
+    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::V3::DeleteCommand) }
 
     it 'is initialized with elastic stack arguments' do
       expect(subject.name).to eq('elastic-stack')

spec/models/clusters/applications/fluentd_spec.rb

@@ -21,7 +21,7 @@ RSpec.describe Clusters::Applications::Fluentd do
   describe '#install_command' do
     subject { fluentd.install_command }
 
-    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::InstallCommand) }
+    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::V3::InstallCommand) }
 
     it 'is initialized with fluentd arguments' do
       expect(subject.name).to eq('fluentd')

spec/models/clusters/applications/helm_spec.rb

@@ -56,7 +56,7 @@ RSpec.describe Clusters::Applications::Helm do
     subject { application.issue_client_cert }
 
     it 'returns a new cert' do
-      is_expected.to be_kind_of(Gitlab::Kubernetes::Helm::Certificate)
+      is_expected.to be_kind_of(Gitlab::Kubernetes::Helm::V2::Certificate)
       expect(subject.cert_string).not_to eq(application.ca_cert)
       expect(subject.key_string).not_to eq(application.ca_key)
     end
@@ -67,7 +67,7 @@ RSpec.describe Clusters::Applications::Helm do
 
     subject { helm.install_command }
 
-    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::InitCommand) }
+    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::V2::InitCommand) }
 
     it 'is initialized with 1 arguments' do
       expect(subject.name).to eq('helm')
@@ -104,7 +104,7 @@ RSpec.describe Clusters::Applications::Helm do
 
     subject { helm.uninstall_command }
 
-    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::ResetCommand) }
+    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::V2::ResetCommand) }
 
     it 'has name' do
       expect(subject.name).to eq('helm')

spec/models/clusters/applications/ingress_spec.rb

@@ -131,7 +131,7 @@ RSpec.describe Clusters::Applications::Ingress do
   describe '#install_command' do
     subject { ingress.install_command }
 
-    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::InstallCommand) }
+    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::V3::InstallCommand) }
 
     it 'is initialized with ingress arguments' do
       expect(subject.name).to eq('ingress')

spec/models/clusters/applications/jupyter_spec.rb

@@ -52,7 +52,7 @@ RSpec.describe Clusters::Applications::Jupyter do
 
     subject { jupyter.install_command }
 
-    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::InstallCommand) }
+    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::V3::InstallCommand) }
 
     it 'is initialized with 4 arguments' do
       expect(subject.name).to eq('jupyter')

spec/models/clusters/applications/knative_spec.rb

@@ -119,7 +119,7 @@ RSpec.describe Clusters::Applications::Knative do
 
   shared_examples 'a command' do
     it 'is an instance of Helm::InstallCommand' do
-      expect(subject).to be_an_instance_of(Gitlab::Kubernetes::Helm::InstallCommand)
+      expect(subject).to be_an_instance_of(Gitlab::Kubernetes::Helm::V3::InstallCommand)
     end
 
     it 'is initialized with knative arguments' do
@@ -171,7 +171,7 @@ RSpec.describe Clusters::Applications::Knative do
   describe '#uninstall_command' do
     subject { knative.uninstall_command }
 
-    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::DeleteCommand) }
+    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::V3::DeleteCommand) }
 
     it "removes knative deployed services before uninstallation" do
       2.times do |i|

spec/models/clusters/applications/prometheus_spec.rb

@@ -148,7 +148,7 @@ RSpec.describe Clusters::Applications::Prometheus do
 
     subject { prometheus.install_command }
 
-    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::InstallCommand) }
+    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::V3::InstallCommand) }
 
     it 'is initialized with 3 arguments' do
       expect(subject.name).to eq('prometheus')
@@ -195,7 +195,7 @@ RSpec.describe Clusters::Applications::Prometheus do
 
     subject { prometheus.uninstall_command }
 
-    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::DeleteCommand) }
+    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::V3::DeleteCommand) }
 
     it 'has the application name' do
       expect(subject.name).to eq('prometheus')
@@ -236,7 +236,7 @@ RSpec.describe Clusters::Applications::Prometheus do
     let(:prometheus) { build(:clusters_applications_prometheus) }
     let(:values) { prometheus.values }
 
-    it { is_expected.to be_an_instance_of(::Gitlab::Kubernetes::Helm::PatchCommand) }
+    it { is_expected.to be_an_instance_of(::Gitlab::Kubernetes::Helm::V3::PatchCommand) }
 
     it 'is initialized with 3 arguments' do
       expect(patch_command.name).to eq('prometheus')

spec/models/clusters/applications/runner_spec.rb

@@ -27,7 +27,7 @@ RSpec.describe Clusters::Applications::Runner do
 
     subject { gitlab_runner.install_command }
 
-    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::InstallCommand) }
+    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::V3::InstallCommand) }
 
     it 'is initialized with 4 arguments' do
       expect(subject.name).to eq('runner')

spec/models/clusters/cluster_spec.rb

@@ -540,6 +540,27 @@ RSpec.describe Clusters::Cluster, :use_clean_rails_memory_store_caching do
         end
       end
     end
+
+    describe 'helm_major_version can only be 2 or 3' do
+      using RSpec::Parameterized::TableSyntax
+
+      where(:helm_major_version, :expect_valid) do
+        2  | true
+        3  | true
+        4  | false
+        -1 | false
+      end
+
+      with_them do
+        let(:cluster) { build(:cluster, helm_major_version: helm_major_version) }
+
+        it { is_expected.to eq(expect_valid) }
+      end
+    end
+  end
+
+  it 'has default helm_major_version 3' do
+    expect(create(:cluster).helm_major_version).to eq(3)
   end
 
   describe '.ancestor_clusters_for_clusterable' do

spec/services/clusters/applications/uninstall_service_spec.rb

@@ -14,7 +14,7 @@ RSpec.describe Clusters::Applications::UninstallService, '#execute' do
 
   context 'when there are no errors' do
     before do
-      expect(helm_client).to receive(:uninstall).with(kind_of(Gitlab::Kubernetes::Helm::DeleteCommand))
+      expect(helm_client).to receive(:uninstall).with(kind_of(Gitlab::Kubernetes::Helm::V3::DeleteCommand))
       allow(worker_class).to receive(:perform_in).and_return(nil)
     end
 
@@ -36,7 +36,7 @@ RSpec.describe Clusters::Applications::UninstallService, '#execute' do
     let(:error) { Kubeclient::HttpError.new(500, 'system failure', nil) }
 
     before do
-      expect(helm_client).to receive(:uninstall).with(kind_of(Gitlab::Kubernetes::Helm::DeleteCommand)).and_raise(error)
+      expect(helm_client).to receive(:uninstall).with(kind_of(Gitlab::Kubernetes::Helm::V3::DeleteCommand)).and_raise(error)
     end
 
     include_examples 'logs kubernetes errors' do
@@ -58,7 +58,7 @@ RSpec.describe Clusters::Applications::UninstallService, '#execute' do
     let(:error) { StandardError.new('something bad happened') }
 
     before do
-      expect(helm_client).to receive(:uninstall).with(kind_of(Gitlab::Kubernetes::Helm::DeleteCommand)).and_raise(error)
+      expect(helm_client).to receive(:uninstall).with(kind_of(Gitlab::Kubernetes::Helm::V3::DeleteCommand)).and_raise(error)
     end
 
     include_examples 'logs kubernetes errors' do

spec/support/shared_examples/helm_commands_shared_examples.rb

@@ -15,6 +15,18 @@ RSpec.shared_examples 'helm command generator' do
 end
 
 RSpec.shared_examples 'helm command' do
+  describe 'HELM_VERSION' do
+    subject { command.class::HELM_VERSION }
+
+    it { is_expected.to match(/\d+\.\d+\.\d+/) }
+  end
+
+  describe '#env' do
+    subject { command.env }
+
+    it { is_expected.to be_a Hash }
+  end
+
   describe '#rbac?' do
     subject { command.rbac? }
 

spec/support/shared_examples/models/cluster_application_core_shared_examples.rb

@@ -25,4 +25,21 @@ RSpec.shared_examples 'cluster application core specs' do |application_name|
   describe '.association_name' do
     it { expect(described_class.association_name).to eq(:"application_#{subject.name}") }
   end
+
+  describe '#helm_command_module' do
+    using RSpec::Parameterized::TableSyntax
+
+    where(:helm_major_version, :expected_helm_command_module) do
+      2 | Gitlab::Kubernetes::Helm::V2
+      3 | Gitlab::Kubernetes::Helm::V3
+    end
+
+    with_them do
+      subject { described_class.new(cluster: cluster).helm_command_module }
+
+      let(:cluster) { build(:cluster, helm_major_version: helm_major_version)}
+
+      it { is_expected.to eq(expected_helm_command_module) }
+    end
+  end
 end

spec/support/shared_examples/models/cluster_application_helm_cert_shared_examples.rb

@@ -6,7 +6,7 @@ RSpec.shared_examples 'cluster application helm specs' do |application_name|
   describe '#uninstall_command' do
     subject { application.uninstall_command }
 
-    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::DeleteCommand) }
+    it { is_expected.to be_an_instance_of(Gitlab::Kubernetes::Helm::V3::DeleteCommand) }
 
     it 'has files' do
       expect(subject.files).to eq(application.files)