Make KubernetesService readonly

We are deprecating this service in favor of instance wide clusters.
Therefore we removed some code that is not anymore needed for a
readonly cluster and also we added some flags to allow for this
deprecation. These flags are to be removed in the next release when
we finally completelly remove KubernetesService.

28 files changed, 132 insertions, 319 deletions

diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index 63b1685feda..698570efb07 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -799,7 +799,6 @@ Style/SelfAssignment:
   Exclude:
     - 'app/models/concerns/bulk_member_access_load.rb'
     - 'app/serializers/base_serializer.rb'
-    - 'spec/features/projects/clusters/interchangeability_spec.rb'
     - 'spec/support/import_export/configuration_helper.rb'
 
 # Offense count: 50
diff --git a/app/assets/stylesheets/pages/settings.scss b/app/assets/stylesheets/pages/settings.scss
index 0a9c56f5625..3b62121eb0d 100644
--- a/app/assets/stylesheets/pages/settings.scss
+++ b/app/assets/stylesheets/pages/settings.scss
@@ -340,6 +340,11 @@
 
 .deprecated-service {
   cursor: default;
+
+  a {
+    font-weight: $gl-font-weight-bold;
+    color: $white-light;
+  }
 }
 
 .personal-access-tokens-never-expires-label {
diff --git a/app/helpers/services_helper.rb b/app/helpers/services_helper.rb
index d4b50b7ecfb..01ccf163b45 100644
--- a/app/helpers/services_helper.rb
+++ b/app/helpers/services_helper.rb
@@ -39,7 +39,7 @@ module ServicesHelper
   end
 
   def disable_fields_service?(service)
-    !current_controller?("admin/services") && service.deprecated?
+    service.is_a?(KubernetesService) || (!current_controller?("admin/services") && service.deprecated?)
   end
 
   extend self
diff --git a/app/models/project_services/deployment_service.rb b/app/models/project_services/deployment_service.rb
deleted file mode 100644
index 80aa2101509..00000000000
--- a/app/models/project_services/deployment_service.rb
+++ /dev/null
@@ -1,39 +0,0 @@
-# frozen_string_literal: true
-
-# Base class for deployment services
-#
-# These services integrate with a deployment solution like Kubernetes/OpenShift,
-# Mesosphere, etc, to provide additional features to environments.
-class DeploymentService < Service
-  default_value_for :category, 'deployment'
-
-  def self.supported_events
-    %w()
-  end
-
-  def predefined_variables(project:)
-    []
-  end
-
-  # Environments may have a number of terminals. Should return an array of
-  # hashes describing them, e.g.:
-  #
-  #     [{
-  #       :selectors    => {"a" => "b", "foo" => "bar"},
-  #       :url          => "wss://external.example.com/exec",
-  #       :headers      => {"Authorization" => "Token xxx"},
-  #       :subprotocols => ["foo"],
-  #       :ca_pem       => "----BEGIN CERTIFICATE...", # optional
-  #       :created_at   => Time.now.utc
-  #     }]
-  #
-  # Selectors should be a set of values that uniquely identify a particular
-  # terminal
-  def terminals(environment)
-    raise NotImplementedError
-  end
-
-  def can_test?
-    false
-  end
-end
diff --git a/app/models/project_services/kubernetes_service.rb b/app/models/project_services/kubernetes_service.rb
index aa6b4aa1d5e..edf7e886e77 100644
--- a/app/models/project_services/kubernetes_service.rb
+++ b/app/models/project_services/kubernetes_service.rb
@@ -5,10 +5,12 @@
 # We'll move this class to Clusters::Platforms::Kubernetes, which contains exactly the same logic.
 # After we've migrated data, we'll remove KubernetesService. This would happen in a few months.
 # If you're modyfiyng this class, please note that you should update the same change in Clusters::Platforms::Kubernetes.
-class KubernetesService < DeploymentService
+class KubernetesService < Service
   include Gitlab::Kubernetes
   include ReactiveCaching
 
+  default_value_for :category, 'deployment'
+
   self.reactive_cache_key = ->(service) { [service.class.model_name.singular, service.project_id] }
 
   # Namespace defaults to the project path, but can be overridden in case that
@@ -32,7 +34,10 @@ class KubernetesService < DeploymentService
 
   before_validation :enforce_namespace_to_lower_case
 
-  validate :deprecation_validation, unless: :template?
+  attr_accessor :skip_deprecation_validation
+
+  validate :deprecation_validation, unless: :skip_deprecation_validation
+
   validates :namespace,
     allow_blank: true,
     length: 1..63,
@@ -44,6 +49,14 @@ class KubernetesService < DeploymentService
 
   after_save :clear_reactive_cache!
 
+  def self.supported_events
+    %w()
+  end
+
+  def can_test?
+    false
+  end
+
   def initialize_properties
     self.properties = {} if properties.nil?
   end
@@ -56,11 +69,6 @@ class KubernetesService < DeploymentService
     'Kubernetes / OpenShift integration'
   end
 
-  def help
-    'To enable terminal access to Kubernetes environments, label your ' \
-    'deployments with `app=$CI_ENVIRONMENT_SLUG`'
-  end
-
   def self.to_param
     'kubernetes'
   end
@@ -153,14 +161,25 @@ class KubernetesService < DeploymentService
   end
 
   def deprecated?
-    !active
+    true
+  end
+
+  def editable?
+    false
   end
 
   def deprecation_message
-    content = _("Kubernetes service integration has been deprecated. %{deprecated_message_content} your Kubernetes clusters using the new <a href=\"%{url}\"/>Kubernetes Clusters</a> page") % {
-      deprecated_message_content: deprecated_message_content,
-      url: Gitlab::Routing.url_helpers.project_clusters_path(project)
-    }
+    content = if project
+                _("Kubernetes service integration has been deprecated. %{deprecated_message_content} your Kubernetes clusters using the new <a href=\"%{url}\"/>Kubernetes Clusters</a> page") % {
+                  deprecated_message_content: deprecated_message_content,
+                  url: Gitlab::Routing.url_helpers.project_clusters_path(project)
+                }
+              else
+                _("The instance-level Kubernetes service integration is deprecated. Your data has been migrated to an <a href=\"%{url}\"/>instance-level cluster</a>.") % {
+                  url: Gitlab::Routing.url_helpers.admin_clusters_path
+                }
+              end
+
     content.html_safe
   end
 
@@ -243,10 +262,6 @@ class KubernetesService < DeploymentService
   end
 
   def deprecated_message_content
-    if active?
-      _("Your Kubernetes cluster information on this page is still editable, but you are advised to disable and reconfigure")
-    else
-      _("Fields on this page are now uneditable, you can configure")
-    end
+    _("Fields on this page are now uneditable, you can configure")
   end
 end
diff --git a/app/models/project_services/mock_deployment_service.rb b/app/models/project_services/mock_deployment_service.rb
index 7ab1687f8ba..1103cb11e73 100644
--- a/app/models/project_services/mock_deployment_service.rb
+++ b/app/models/project_services/mock_deployment_service.rb
@@ -1,6 +1,8 @@
 # frozen_string_literal: true
 
-class MockDeploymentService < DeploymentService
+class MockDeploymentService < Service
+  default_value_for :category, 'deployment'
+
   def title
     'Mock deployment'
   end
@@ -17,4 +19,16 @@ class MockDeploymentService < DeploymentService
   def terminals(environment)
     []
   end
+
+  def self.supported_events
+    %w()
+  end
+
+  def predefined_variables(project:)
+    []
+  end
+
+  def can_test?
+    false
+  end
 end
diff --git a/app/views/admin/services/_deprecated_message.html.haml b/app/views/admin/services/_deprecated_message.html.haml
new file mode 100644
index 00000000000..fea9506a4bb
--- /dev/null
+++ b/app/views/admin/services/_deprecated_message.html.haml
@@ -0,0 +1,3 @@
+.flash-container.flash-container-page
+  .flash-alert.deprecated-service
+    %span= @service.deprecation_message
diff --git a/app/views/admin/services/_form.html.haml b/app/views/admin/services/_form.html.haml
index 1798b44bbb7..97373a3c350 100644
--- a/app/views/admin/services/_form.html.haml
+++ b/app/views/admin/services/_form.html.haml
@@ -6,5 +6,6 @@
 = form_for :service, url: admin_application_settings_service_path, method: :put, html: { class: 'fieldset-form' } do |form|
   = render 'shared/service_settings', form: form, subject: @service
 
-  .footer-block.row-content-block
-    = form.submit 'Save', class: 'btn btn-success'
+  - unless @service.is_a?(KubernetesService)
+    .footer-block.row-content-block
+      = form.submit 'Save', class: 'btn btn-success'
diff --git a/app/views/admin/services/edit.html.haml b/app/views/admin/services/edit.html.haml
index 512176649e6..79f5ab0d77d 100644
--- a/app/views/admin/services/edit.html.haml
+++ b/app/views/admin/services/edit.html.haml
@@ -1,4 +1,7 @@
 - add_to_breadcrumbs "Service Templates", admin_application_settings_services_path
 - breadcrumb_title @service.title
 - page_title @service.title, "Service Templates"
+
+= render 'deprecated_message' if @service.deprecation_message
+
 = render 'form'
diff --git a/changelogs/unreleased/readonly_k8s_integration.yml b/changelogs/unreleased/readonly_k8s_integration.yml
new file mode 100644
index 00000000000..718705e8750
--- /dev/null
+++ b/changelogs/unreleased/readonly_k8s_integration.yml
@@ -0,0 +1,5 @@
+---
+title: Make Kubernetes service templates readonly
+merge_request: 29044
+author:
+type: removed
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index 186c4cb2dba..0cabaeabb9a 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -9999,6 +9999,9 @@ msgstr ""
 msgid "The import will time out after %{timeout}. For repositories that take longer, use a clone/push combination."
 msgstr ""
 
+msgid "The instance-level Kubernetes service integration is deprecated. Your data has been migrated to an <a href=\"%{url}\"/>instance-level cluster</a>."
+msgstr ""
+
 msgid "The invitation could not be accepted."
 msgstr ""
 
@@ -11943,9 +11946,6 @@ msgstr ""
 msgid "Your Groups"
 msgstr ""
 
-msgid "Your Kubernetes cluster information on this page is still editable, but you are advised to disable and reconfigure"
-msgstr ""
-
 msgid "Your Primary Email will be used for avatar detection."
 msgstr ""
 
diff --git a/spec/controllers/projects/branches_controller_spec.rb b/spec/controllers/projects/branches_controller_spec.rb
index c778b7888dc..cf201c9f735 100644
--- a/spec/controllers/projects/branches_controller_spec.rb
+++ b/spec/controllers/projects/branches_controller_spec.rb
@@ -123,7 +123,11 @@ describe Projects::BranchesController do
           expect(response).to redirect_to project_tree_path(project, branch)
         end
 
-        shared_examples 'same behavior between KubernetesService and Platform::Kubernetes' do
+        context 'when user configured kubernetes from CI/CD > Clusters' do
+          before do
+            create(:cluster, :provided_by_gcp, projects: [project])
+          end
+
           it 'redirects to autodeploy setup page' do
             result = { status: :success, branch: double(name: branch) }
 
@@ -143,22 +147,6 @@ describe Projects::BranchesController do
           end
         end
 
-        context 'when user configured kubernetes from Integration > Kubernetes' do
-          before do
-            project.services << build(:kubernetes_service)
-          end
-
-          it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-        end
-
-        context 'when user configured kubernetes from CI/CD > Clusters' do
-          before do
-            create(:cluster, :provided_by_gcp, projects: [project])
-          end
-
-          it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-        end
-
         it 'redirects to autodeploy setup page' do
           result = { status: :success, branch: double(name: branch) }
 
diff --git a/spec/controllers/projects/services_controller_spec.rb b/spec/controllers/projects/services_controller_spec.rb
index 3608d175d50..5c7f8d95f82 100644
--- a/spec/controllers/projects/services_controller_spec.rb
+++ b/spec/controllers/projects/services_controller_spec.rb
@@ -141,20 +141,6 @@ describe Projects::ServicesController do
       end
     end
 
-    context 'with a deprecated service' do
-      let(:service) { create(:kubernetes_service, project: project) }
-
-      before do
-        put :update,
-          params: { namespace_id: project.namespace, project_id: project, id: service.to_param, service: { namespace: 'updated_namespace' } }
-      end
-
-      it 'does not update the service' do
-        service.reload
-        expect(service.namespace).not_to eq('updated_namespace')
-      end
-    end
-
     context 'when activating JIRA service from a template' do
       let(:template_service) { create(:jira_service, project: project, template: true) }
 
@@ -168,20 +154,10 @@ describe Projects::ServicesController do
 
   describe "GET #edit" do
     before do
-      get :edit, params: { namespace_id: project.namespace, project_id: project, id: service_id }
+      get :edit, params: { namespace_id: project.namespace, project_id: project, id: 'jira' }
     end
 
     context 'with approved services' do
-      let(:service_id) { 'jira' }
-
-      it 'renders edit page' do
-        expect(response).to be_success
-      end
-    end
-
-    context 'with a deprecated service' do
-      let(:service_id) { 'kubernetes' }
-
       it 'renders edit page' do
         expect(response).to be_success
       end
diff --git a/spec/factories/services.rb b/spec/factories/services.rb
index 0d8c26a2ee9..763909f30bd 100644
--- a/spec/factories/services.rb
+++ b/spec/factories/services.rb
@@ -24,6 +24,8 @@ FactoryBot.define do
       api_url: 'https://kubernetes.example.com',
       token: 'a' * 40
     })
+
+    skip_deprecation_validation true
   end
 
   factory :mock_deployment_service do
diff --git a/spec/features/projects/clusters/interchangeability_spec.rb b/spec/features/projects/clusters/interchangeability_spec.rb
deleted file mode 100644
index 0033e12b6b1..00000000000
--- a/spec/features/projects/clusters/interchangeability_spec.rb
+++ /dev/null
@@ -1,16 +0,0 @@
-require 'spec_helper'
-
-describe 'Interchangeability between KubernetesService and Platform::Kubernetes' do
-  EXCEPT_METHODS = %i[test title description help fields initialize_properties namespace namespace= api_url api_url= deprecated? deprecation_message].freeze
-  EXCEPT_METHODS_GREP_V = %w[_touched? _changed? _was].freeze
-
-  it 'Clusters::Platform::Kubernetes covers core interfaces in KubernetesService' do
-    expected_interfaces = KubernetesService.instance_methods(false)
-    expected_interfaces = expected_interfaces - EXCEPT_METHODS
-    EXCEPT_METHODS_GREP_V.each do |g|
-      expected_interfaces = expected_interfaces.grep_v(/#{Regexp.escape(g)}\z/)
-    end
-
-    expect(expected_interfaces - Clusters::Platforms::Kubernetes.instance_methods).to be_empty
-  end
-end
diff --git a/spec/features/projects/environments/environment_spec.rb b/spec/features/projects/environments/environment_spec.rb
index da4ef6428d4..fbaf12be64e 100644
--- a/spec/features/projects/environments/environment_spec.rb
+++ b/spec/features/projects/environments/environment_spec.rb
@@ -155,7 +155,10 @@ describe 'Environment' do
           end
 
           context 'with terminal' do
-            shared_examples 'same behavior between KubernetesService and Platform::Kubernetes' do
+            context 'when user configured kubernetes from CI/CD > Clusters' do
+              let!(:cluster) { create(:cluster, :project, :provided_by_gcp) }
+              let(:project) { cluster.project }
+
               context 'for project maintainer' do
                 let(:role) { :maintainer }
 
@@ -191,19 +194,6 @@ describe 'Environment' do
                 end
               end
             end
-
-            context 'when user configured kubernetes from Integration > Kubernetes' do
-              let(:project) { create(:kubernetes_project, :test_repo) }
-
-              it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-            end
-
-            context 'when user configured kubernetes from CI/CD > Clusters' do
-              let!(:cluster) { create(:cluster, :project, :provided_by_gcp) }
-              let(:project) { cluster.project }
-
-              it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-            end
           end
 
           context 'when environment is available' do
diff --git a/spec/features/projects/environments/environments_spec.rb b/spec/features/projects/environments/environments_spec.rb
index 7b7e45312d9..1b5d9083932 100644
--- a/spec/features/projects/environments/environments_spec.rb
+++ b/spec/features/projects/environments/environments_spec.rb
@@ -248,7 +248,10 @@ describe 'Environments page', :js do
         end
 
         context 'when kubernetes terminal is available' do
-          shared_examples 'same behavior between KubernetesService and Platform::Kubernetes' do
+          context 'when user configured kubernetes from CI/CD > Clusters' do
+            let(:cluster) { create(:cluster, :provided_by_gcp, projects: [create(:project, :repository)]) }
+            let(:project) { cluster.project }
+
             context 'for project maintainer' do
               let(:role) { :maintainer }
 
@@ -265,19 +268,6 @@ describe 'Environments page', :js do
               end
             end
           end
-
-          context 'when user configured kubernetes from Integration > Kubernetes' do
-            let(:project) { create(:kubernetes_project, :test_repo) }
-
-            it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-          end
-
-          context 'when user configured kubernetes from CI/CD > Clusters' do
-            let(:cluster) { create(:cluster, :provided_by_gcp, projects: [create(:project, :repository)]) }
-            let(:project) { cluster.project }
-
-            it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-          end
         end
       end
 
diff --git a/spec/lib/gitlab/ci/build/policy/kubernetes_spec.rb b/spec/lib/gitlab/ci/build/policy/kubernetes_spec.rb
index 4884d5f8ba4..4510b82ca9d 100644
--- a/spec/lib/gitlab/ci/build/policy/kubernetes_spec.rb
+++ b/spec/lib/gitlab/ci/build/policy/kubernetes_spec.rb
@@ -4,24 +4,14 @@ describe Gitlab::Ci::Build::Policy::Kubernetes do
   let(:pipeline) { create(:ci_pipeline, project: project) }
 
   context 'when kubernetes service is active' do
-    shared_examples 'same behavior between KubernetesService and Platform::Kubernetes' do
-      it 'is satisfied by a kubernetes pipeline' do
-        expect(described_class.new('active'))
-          .to be_satisfied_by(pipeline)
-      end
-    end
-
-    context 'when user configured kubernetes from Integration > Kubernetes' do
-      let(:project) { create(:kubernetes_project) }
-
-      it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-    end
-
     context 'when user configured kubernetes from CI/CD > Clusters' do
       let!(:cluster) { create(:cluster, :project, :provided_by_gcp) }
       let(:project) { cluster.project }
 
-      it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
+      it 'is satisfied by a kubernetes pipeline' do
+        expect(described_class.new('active'))
+          .to be_satisfied_by(pipeline)
+      end
     end
   end
 
diff --git a/spec/models/ci/pipeline_spec.rb b/spec/models/ci/pipeline_spec.rb
index c4e54be673f..6ebc6337d50 100644
--- a/spec/models/ci/pipeline_spec.rb
+++ b/spec/models/ci/pipeline_spec.rb
@@ -962,7 +962,11 @@ describe Ci::Pipeline, :mailer do
         end
 
         context 'when kubernetes is active' do
-          shared_examples 'same behavior between KubernetesService and Platform::Kubernetes' do
+          context 'when user configured kubernetes from CI/CD > Clusters' do
+            let!(:cluster) { create(:cluster, :project, :provided_by_gcp) }
+            let(:project) { cluster.project }
+            let(:pipeline) { build(:ci_pipeline, project: project, config: config) }
+
             it 'returns seeds for kubernetes dependent job' do
               seeds = pipeline.stage_seeds
 
@@ -971,21 +975,6 @@ describe Ci::Pipeline, :mailer do
               expect(seeds.dig(1, 0, :name)).to eq 'production'
             end
           end
-
-          context 'when user configured kubernetes from Integration > Kubernetes' do
-            let(:project) { create(:kubernetes_project) }
-            let(:pipeline) { build(:ci_pipeline, project: project, config: config) }
-
-            it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-          end
-
-          context 'when user configured kubernetes from CI/CD > Clusters' do
-            let!(:cluster) { create(:cluster, :project, :provided_by_gcp) }
-            let(:project) { cluster.project }
-            let(:pipeline) { build(:ci_pipeline, project: project, config: config) }
-
-            it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-          end
         end
 
         context 'when kubernetes is not active' do
@@ -1679,23 +1668,13 @@ describe Ci::Pipeline, :mailer do
 
   describe '#has_kubernetes_active?' do
     context 'when kubernetes is active' do
-      shared_examples 'same behavior between KubernetesService and Platform::Kubernetes' do
-        it 'returns true' do
-          expect(pipeline).to have_kubernetes_active
-        end
-      end
-
-      context 'when user configured kubernetes from Integration > Kubernetes' do
-        let(:project) { create(:kubernetes_project) }
-
-        it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-      end
-
       context 'when user configured kubernetes from CI/CD > Clusters' do
         let!(:cluster) { create(:cluster, :project, :provided_by_gcp) }
         let(:project) { cluster.project }
 
-        it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
+        it 'returns true' do
+          expect(pipeline).to have_kubernetes_active
+        end
       end
     end
 
diff --git a/spec/models/environment_spec.rb b/spec/models/environment_spec.rb
index 7233d2454c6..379dda1f5c4 100644
--- a/spec/models/environment_spec.rb
+++ b/spec/models/environment_spec.rb
@@ -515,29 +515,19 @@ describe Environment do
 
     context 'when the environment is available' do
       context 'with a deployment service' do
-        shared_examples 'same behavior between KubernetesService and Platform::Kubernetes' do
-          context 'and a deployment' do
+        context 'when user configured kubernetes from CI/CD > Clusters' do
+          let!(:cluster) { create(:cluster, :project, :provided_by_gcp) }
+          let(:project) { cluster.project }
+
+          context 'with deployment' do
             let!(:deployment) { create(:deployment, :success, environment: environment) }
             it { is_expected.to be_truthy }
           end
 
-          context 'but no deployments' do
+          context 'without deployments' do
             it { is_expected.to be_falsy }
           end
         end
-
-        context 'when user configured kubernetes from Integration > Kubernetes' do
-          let(:project) { create(:kubernetes_project) }
-
-          it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-        end
-
-        context 'when user configured kubernetes from CI/CD > Clusters' do
-          let!(:cluster) { create(:cluster, :project, :provided_by_gcp) }
-          let(:project) { cluster.project }
-
-          it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-        end
       end
 
       context 'without a deployment service' do
@@ -546,8 +536,6 @@ describe Environment do
     end
 
     context 'when the environment is unavailable' do
-      let(:project) { create(:kubernetes_project) }
-
       before do
         environment.stop
       end
@@ -590,7 +578,10 @@ describe Environment do
         allow(environment).to receive(:has_terminals?).and_return(true)
       end
 
-      shared_examples 'same behavior between KubernetesService and Platform::Kubernetes' do
+      context 'when user configured kubernetes from CI/CD > Clusters' do
+        let!(:cluster) { create(:cluster, :project, :provided_by_gcp) }
+        let(:project) { cluster.project }
+
         it 'returns the terminals from the deployment service' do
           expect(environment.deployment_platform)
             .to receive(:terminals).with(environment)
@@ -599,19 +590,6 @@ describe Environment do
           is_expected.to eq(:fake_terminals)
         end
       end
-
-      context 'when user configured kubernetes from Integration > Kubernetes' do
-        let(:project) { create(:kubernetes_project) }
-
-        it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-      end
-
-      context 'when user configured kubernetes from CI/CD > Clusters' do
-        let!(:cluster) { create(:cluster, :project, :provided_by_gcp) }
-        let(:project) { cluster.project }
-
-        it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-      end
     end
 
     context 'when the environment does not have terminals' do
diff --git a/spec/models/project_services/kubernetes_service_spec.rb b/spec/models/project_services/kubernetes_service_spec.rb
index 2fce120381b..34ee1eafd5c 100644
--- a/spec/models/project_services/kubernetes_service_spec.rb
+++ b/spec/models/project_services/kubernetes_service_spec.rb
@@ -17,6 +17,7 @@ describe KubernetesService, :use_clean_rails_memory_store_caching do
     context 'when service is active' do
       before do
         subject.active = true
+        subject.skip_deprecation_validation = true
       end
 
       it { is_expected.not_to validate_presence_of(:namespace) }
@@ -67,6 +68,7 @@ describe KubernetesService, :use_clean_rails_memory_store_caching do
 
       before do
         kubernetes_service.update_attribute(:active, false)
+        kubernetes_service.skip_deprecation_validation = false
         kubernetes_service.properties['namespace'] = "foo"
       end
 
@@ -80,19 +82,11 @@ describe KubernetesService, :use_clean_rails_memory_store_caching do
       end
     end
 
-    context 'with a non-deprecated service' do
-      let(:kubernetes_service) { create(:kubernetes_service) }
-
-      it 'updates attributes' do
-        kubernetes_service.properties['namespace'] = 'foo'
-        expect(kubernetes_service.save).to be_truthy
-      end
-    end
-
     context 'with an active and deprecated service' do
       let(:kubernetes_service) { create(:kubernetes_service) }
 
       before do
+        kubernetes_service.skip_deprecation_validation = false
         kubernetes_service.active = false
         kubernetes_service.properties['namespace'] = 'foo'
         kubernetes_service.save
@@ -110,19 +104,6 @@ describe KubernetesService, :use_clean_rails_memory_store_caching do
         expect(kubernetes_service.properties['namespace']).to eq("foo")
       end
     end
-
-    context 'with a template service' do
-      let(:kubernetes_service) { create(:kubernetes_service, template: true, active: false) }
-
-      before do
-        kubernetes_service.properties['namespace'] = 'foo'
-      end
-
-      it 'updates attributes' do
-        expect(kubernetes_service.save).to be_truthy
-        expect(kubernetes_service.properties['namespace']).to eq('foo')
-      end
-    end
   end
 
   describe '#initialize_properties' do
@@ -393,17 +374,8 @@ describe KubernetesService, :use_clean_rails_memory_store_caching do
   describe "#deprecated?" do
     let(:kubernetes_service) { create(:kubernetes_service) }
 
-    context 'with an active kubernetes service' do
-      it 'returns false' do
-        expect(kubernetes_service.deprecated?).to be_falsy
-      end
-    end
-
-    context 'with a inactive kubernetes service' do
-      it 'returns true' do
-        kubernetes_service.update_attribute(:active, false)
-        expect(kubernetes_service.deprecated?).to be_truthy
-      end
+    it 'returns true' do
+      expect(kubernetes_service.deprecated?).to be_truthy
     end
   end
 
@@ -414,12 +386,6 @@ describe KubernetesService, :use_clean_rails_memory_store_caching do
       expect(kubernetes_service.deprecation_message).to match(/Kubernetes service integration has been deprecated/)
     end
 
-    context 'if the services is active' do
-      it 'returns a message' do
-        expect(kubernetes_service.deprecation_message).to match(/Your Kubernetes cluster information on this page is still editable/)
-      end
-    end
-
     context 'if the service is not active' do
       it 'returns a message' do
         kubernetes_service.update_attribute(:active, false)
diff --git a/spec/models/project_spec.rb b/spec/models/project_spec.rb
index 269d2bb90d3..20b98b5eb85 100644
--- a/spec/models/project_spec.rb
+++ b/spec/models/project_spec.rb
@@ -2652,7 +2652,10 @@ describe Project do
     end
 
     context 'when project has a deployment service' do
-      shared_examples 'same behavior between KubernetesService and Platform::Kubernetes' do
+      context 'when user configured kubernetes from CI/CD > Clusters and KubernetesNamespace migration has not been executed' do
+        let!(:cluster) { create(:cluster, :project, :provided_by_gcp) }
+        let(:project) { cluster.project }
+
         it 'returns variables from this service' do
           expect(project.deployment_variables).to include(
             { key: 'KUBE_TOKEN', value: project.deployment_platform.token, public: false, masked: true }
@@ -2660,19 +2663,6 @@ describe Project do
         end
       end
 
-      context 'when user configured kubernetes from Integration > Kubernetes' do
-        let(:project) { create(:kubernetes_project) }
-
-        it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-      end
-
-      context 'when user configured kubernetes from CI/CD > Clusters and KubernetesNamespace migration has not been executed' do
-        let!(:cluster) { create(:cluster, :project, :provided_by_gcp) }
-        let(:project) { cluster.project }
-
-        it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-      end
-
       context 'when user configured kubernetes from CI/CD > Clusters and KubernetesNamespace migration has been executed' do
         let!(:kubernetes_namespace) { create(:cluster_kubernetes_namespace, :with_token) }
         let!(:cluster) { kubernetes_namespace.cluster }
diff --git a/spec/models/service_spec.rb b/spec/models/service_spec.rb
index c9439b0846d..d442c73c118 100644
--- a/spec/models/service_spec.rb
+++ b/spec/models/service_spec.rb
@@ -82,7 +82,7 @@ describe Service do
       context 'when template is invalid' do
         it 'sets service template to inactive when template is invalid' do
           project = create(:project)
-          template = KubernetesService.new(template: true, active: true)
+          template = build(:prometheus_service, template: true, active: true, properties: {})
           template.save(validate: false)
 
           service = described_class.build_from_template(project.id, template)
@@ -309,10 +309,10 @@ describe Service do
   end
 
   describe '.find_by_template' do
-    let!(:kubernetes_service) { create(:kubernetes_service, template: true) }
+    let!(:service) { create(:service, template: true) }
 
     it 'returns service template' do
-      expect(KubernetesService.find_by_template).to eq(kubernetes_service)
+      expect(described_class.find_by_template).to eq(service)
     end
   end
 
diff --git a/spec/requests/api/services_spec.rb b/spec/requests/api/services_spec.rb
index 8065c077ca0..3f79e332b90 100644
--- a/spec/requests/api/services_spec.rb
+++ b/spec/requests/api/services_spec.rb
@@ -10,7 +10,10 @@ describe API::Services do
   end
 
   Service.available_services_names.each do |service|
-    describe "PUT /projects/:id/services/#{service.dasherize}" do
+    # TODO: Remove below `if: (service != "kubernetes")` in the next release
+    # KubernetesService was deprecated and it can't be updated. Right now it's
+    # only readable. It should be completely removed in the next iteration.
+    describe "PUT /projects/:id/services/#{service.dasherize}", if: (service != "kubernetes") do
       include_context service
 
       it "updates #{service} settings" do
@@ -59,7 +62,10 @@ describe API::Services do
       end
     end
 
-    describe "DELETE /projects/:id/services/#{service.dasherize}" do
+    # TODO: Remove below `if: (service != "kubernetes")` in the next release
+    # KubernetesService was deprecated and it can't be updated. Right now it's
+    # only readable. It should be completely removed in the next iteration.
+    describe "DELETE /projects/:id/services/#{service.dasherize}", if: (service != "kubernetes") do
       include_context service
 
       before do
diff --git a/spec/serializers/environment_entity_spec.rb b/spec/serializers/environment_entity_spec.rb
index c2312734042..906449f470b 100644
--- a/spec/serializers/environment_entity_spec.rb
+++ b/spec/serializers/environment_entity_spec.rb
@@ -59,15 +59,5 @@ describe EnvironmentEntity do
         expect(subject[:cluster_type]).to eq('project_type')
       end
     end
-
-    context 'when deployment platform is a Kubernetes Service' do
-      before do
-        create(:kubernetes_service, project: project)
-      end
-
-      it 'does not include cluster_type' do
-        expect(subject).not_to include(:cluster_type)
-      end
-    end
   end
 end
diff --git a/spec/support/prometheus/additional_metrics_shared_examples.rb b/spec/support/prometheus/additional_metrics_shared_examples.rb
index 8044b061ca5..de21e808932 100644
--- a/spec/support/prometheus/additional_metrics_shared_examples.rb
+++ b/spec/support/prometheus/additional_metrics_shared_examples.rb
@@ -44,7 +44,9 @@ RSpec.shared_examples 'additional metrics query' do
     end
 
     describe 'project has Kubernetes service' do
-      shared_examples 'same behavior between KubernetesService and Platform::Kubernetes' do
+      context 'when user configured kubernetes from CI/CD > Clusters' do
+        let!(:cluster) { create(:cluster, :project, :provided_by_gcp) }
+        let(:project) { cluster.project }
         let(:environment) { create(:environment, slug: 'environment-slug', project: project) }
         let(:kube_namespace) { project.deployment_platform.kubernetes_namespace_for(project) }
 
@@ -56,19 +58,6 @@ RSpec.shared_examples 'additional metrics query' do
           subject.query(*query_params)
         end
       end
-
-      context 'when user configured kubernetes from Integration > Kubernetes' do
-        let(:project) { create(:kubernetes_project) }
-
-        it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-      end
-
-      context 'when user configured kubernetes from CI/CD > Clusters' do
-        let!(:cluster) { create(:cluster, :project, :provided_by_gcp) }
-        let(:project) { cluster.project }
-
-        it_behaves_like 'same behavior between KubernetesService and Platform::Kubernetes'
-      end
     end
 
     describe 'project without Kubernetes service' do
diff --git a/spec/support/shared_contexts/services_shared_context.rb b/spec/support/shared_contexts/services_shared_context.rb
index 089f1798cd2..0c3a24d206f 100644
--- a/spec/support/shared_contexts/services_shared_context.rb
+++ b/spec/support/shared_contexts/services_shared_context.rb
@@ -37,8 +37,7 @@ Service.available_services_names.each do |service|
     def initialize_service(service)
       service_item = project.find_or_initialize_service(service)
       service_item.properties = service_attrs
-      service_item.active = true if service == "kubernetes"
-      service_item.save
+      service_item.save!
       service_item
     end
   end
diff --git a/spec/workers/reactive_caching_worker_spec.rb b/spec/workers/reactive_caching_worker_spec.rb
index 2395e6ec947..b8ca6063ccd 100644
--- a/spec/workers/reactive_caching_worker_spec.rb
+++ b/spec/workers/reactive_caching_worker_spec.rb
@@ -6,16 +6,6 @@ describe ReactiveCachingWorker do
   let(:service) { project.deployment_platform }
 
   describe '#perform' do
-    context 'when user configured kubernetes from Integration > Kubernetes' do
-      let(:project) { create(:kubernetes_project) }
-
-      it 'calls #exclusively_update_reactive_cache!' do
-        expect_any_instance_of(KubernetesService).to receive(:exclusively_update_reactive_cache!)
-
-        described_class.new.perform("KubernetesService", service.id)
-      end
-    end
-
     context 'when user configured kubernetes from CI/CD > Clusters' do
       let!(:cluster) { create(:cluster, :project, :provided_by_gcp) }
       let(:project) { cluster.project }