Create Kubernetes based on Application Templates

app/models/concerns/deployment_platform.rb

+module DeploymentPlatform
+  def deployment_platform
+    @deployment_platform ||= find_cluster_platform_kubernetes
+    @deployment_platform ||= find_kubernetes_service_integration
+    @deployment_platform ||= build_cluster_and_deployment_platform
+  end
+
+  private
+
+  def find_cluster_platform_kubernetes
+    clusters.find_by(enabled: true)&.platform_kubernetes
+  end
+
+  def find_kubernetes_service_integration
+    services.deployment.reorder(nil).find_by(active: true)
+  end
+
+  def build_cluster_and_deployment_platform
+    return unless kubernetes_service_template
+
+    cluster = ::Clusters::Cluster.create(cluster_attributes_from_service_template)
+    cluster.platform_kubernetes if cluster.persisted?
+  end
+
+  def kubernetes_service_template
+    @kubernetes_service_template ||= KubernetesService.active.find_by_template
+  end
+
+  def cluster_attributes_from_service_template
+    {
+      name: 'kubernetes-template',
+      projects: [self],
+      provider_type: :user,
+      platform_type: :kubernetes,
+      platform_kubernetes_attributes: platform_kubernetes_attributes_from_service_template
+    }
+  end
+
+  def platform_kubernetes_attributes_from_service_template
+    {
+      api_url: kubernetes_service_template.api_url,
+      ca_pem: kubernetes_service_template.ca_pem,
+      token: kubernetes_service_template.token,
+      namespace: kubernetes_service_template.namespace
+    }
+  end
+end

app/models/project.rb

@@ -19,6 +19,7 @@ class Project < ActiveRecord::Base
   include Routable
   include GroupDescendant
   include Gitlab::SQL::Pattern
+  include DeploymentPlatform
   extend Gitlab::ConfigHelper
   extend Gitlab::CurrentSettings
@@ -904,12 +905,6 @@ class Project < ActiveRecord::Base
     @ci_service ||= ci_services.reorder(nil).find_by(active: true)
   end
-  # TODO: This will be extended for multiple enviroment clusters
-  def deployment_platform
-    @deployment_platform ||= clusters.find_by(enabled: true)&.platform_kubernetes
-    @deployment_platform ||= services.where(category: :deployment).reorder(nil).find_by(active: true)
-  end
-
   def monitoring_services
     services.where(category: :monitoring)
   end

app/models/service.rb

@@ -44,6 +44,7 @@ class Service < ActiveRecord::Base
   scope :pipeline_hooks, -> { where(pipeline_events: true, active: true) }
   scope :wiki_page_hooks, -> { where(wiki_page_events: true, active: true) }
   scope :external_issue_trackers, -> { issue_trackers.active.without_defaults }
+  scope :deployment, -> { where(category: 'deployment') }
   default_value_for :category, 'common'
@@ -271,6 +272,10 @@ class Service < ActiveRecord::Base
     nil
   end
+  def self.find_by_template
+    find_by(template: true)
+  end
+
   private
   def cache_project_has_external_issue_tracker

changelogs/unreleased/41056-create-cluster-from-kubernetes-integration-application-template.yml

+---
+title: Allow automatic creation of Kubernetes Integration from template
+merge_request: 16104
+author:
+type: added

spec/features/projects/import_export/export_file_spec.rb

@@ -2,7 +2,7 @@ require 'spec_helper'
 # Integration test that exports a file using the Import/Export feature
 # It looks up for any sensitive word inside the JSON, so if a sensitive word is found
-# we''l have to either include it adding the model that includes it to the +safe_list+
+# we'll have to either include it adding the model that includes it to the +safe_list+
 # or make sure the attribute is blacklisted in the +import_export.yml+ configuration
 feature 'Import/Export - project export integration test', :js do
   include Select2Helper

spec/models/concerns/deployment_platform_spec.rb

+require 'rails_helper'
+
+describe DeploymentPlatform do
+  let(:project) { create(:project) }
+
+  describe '#deployment_platform' do
+    subject { project.deployment_platform }
+
+    context 'with no Kubernetes configuration on CI/CD, no Kubernetes Service and a Kubernetes template configured' do
+      let!(:kubernetes_service) { create(:kubernetes_service, template: true) }
+
+      it 'returns a platform kubernetes' do
+        expect(subject).to be_a_kind_of(Clusters::Platforms::Kubernetes)
+      end
+
+      it 'creates a cluster and a platform kubernetes' do
+        expect { subject }
+          .to change { Clusters::Cluster.count }.by(1)
+          .and change { Clusters::Platforms::Kubernetes.count }.by(1)
+      end
+
+      it 'includes appropriate attributes for Cluster' do
+        cluster = subject.cluster
+        expect(cluster.name).to eq('kubernetes-template')
+        expect(cluster.project).to eq(project)
+        expect(cluster.provider_type).to eq('user')
+        expect(cluster.platform_type).to eq('kubernetes')
+      end
+
+      it 'creates a platform kubernetes' do
+        expect { subject }.to change { Clusters::Platforms::Kubernetes.count }.by(1)
+      end
+
+      it 'copies attributes from Clusters::Platform::Kubernetes template into the new Cluster::Platforms::Kubernetes' do
+        expect(subject.api_url).to eq(kubernetes_service.api_url)
+        expect(subject.ca_pem).to eq(kubernetes_service.ca_pem)
+        expect(subject.token).to eq(kubernetes_service.token)
+        expect(subject.namespace).to eq(kubernetes_service.namespace)
+      end
+    end
+
+    context 'with no Kubernetes configuration on CI/CD, no Kubernetes Service and no Kubernetes template configured' do
+      it { is_expected.to be_nil }
+    end
+
+    context 'when user configured kubernetes from CI/CD > Clusters' do
+      let!(:cluster) { create(:cluster, :provided_by_gcp, projects: [project]) }
+      let(:platform_kubernetes) { cluster.platform_kubernetes }
+
+      it 'returns the Kubernetes platform' do
+        expect(subject).to eq(platform_kubernetes)
+      end
+    end
+
+    context 'when user configured kubernetes integration from project services' do
+      let!(:kubernetes_service) { create(:kubernetes_service, project: project) }
+
+      it 'returns the Kubernetes service' do
+        expect(subject).to eq(kubernetes_service)
+      end
+    end
+
+    context 'when the cluster creation fails' do
+      let!(:kubernetes_service) { create(:kubernetes_service, template: true) }
+
+      before do
+        allow_any_instance_of(Clusters::Cluster).to receive(:persisted?).and_return(false)
+      end
+
+      it { is_expected.to be_nil }
+    end
+  end
+end

spec/models/project_spec.rb

@@ -3137,25 +3137,6 @@ describe Project do
     end
   end
-  describe '#deployment_platform' do
-    subject { project.deployment_platform }
-
-    let(:project) { create(:project) }
-
-    context 'when user configured kubernetes from Integration > Kubernetes' do
-      let!(:kubernetes_service) { create(:kubernetes_service, project: project) }
-
-      it { is_expected.to eq(kubernetes_service) }
-    end
-
-    context 'when user configured kubernetes from CI/CD > Clusters' do
-      let!(:cluster) { create(:cluster, :provided_by_gcp, projects: [project]) }
-      let(:platform_kubernetes) { cluster.platform_kubernetes }
-
-      it { is_expected.to eq(platform_kubernetes) }
-    end
-  end
-
   describe '#write_repository_config' do
     set(:project) { create(:project, :repository) }

spec/models/service_spec.rb

@@ -272,4 +272,12 @@ describe Service do
       expect(service.deprecation_message).to be_nil
     end
   end
+
+  describe '.find_by_template' do
+    let!(:kubernetes_service) { create(:kubernetes_service, template: true) }
+
+    it 'returns service template' do
+      expect(KubernetesService.find_by_template).to eq(kubernetes_service)
+    end
+  end
 end