Migrate Kubernetes service integration templates to clusters

The migration uses active record model stubs so that field encryption
can be more easily used.

changelogs/unreleased/migrate_k8s_service_integration.yml

+---
+title: Migrate Kubernetes service integration templates to clusters
+merge_request: 28534
+author:
+type: added

db/post_migrate/20190517153211_migrate_k8s_service_integration.rb

+# frozen_string_literal: true
+
+class MigrateK8sServiceIntegration < ActiveRecord::Migration[5.1]
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  class Cluster < ActiveRecord::Base
+    self.table_name = 'clusters'
+
+    has_one :platform_kubernetes, class_name: 'MigrateK8sServiceIntegration::PlatformsKubernetes'
+
+    accepts_nested_attributes_for :platform_kubernetes
+
+    enum cluster_type: {
+      instance_type: 1,
+      group_type: 2,
+      project_type: 3
+    }
+
+    enum platform_type: {
+      kubernetes: 1
+    }
+
+    enum provider_type: {
+      user: 0,
+      gcp: 1
+    }
+  end
+
+  class PlatformsKubernetes < ActiveRecord::Base
+    self.table_name = 'cluster_platforms_kubernetes'
+
+    belongs_to :cluster, class_name: 'MigrateK8sServiceIntegration::Cluster'
+
+    attr_encrypted :token,
+      mode: :per_attribute_iv,
+      key: Settings.attr_encrypted_db_key_base_truncated,
+      algorithm: 'aes-256-cbc'
+  end
+
+  class Service < ActiveRecord::Base
+    include EachBatch
+
+    self.table_name = 'services'
+    self.inheritance_column = :_type_disabled # Disable STI, otherwise KubernetesModel will be looked up
+
+    belongs_to :project, class_name: 'MigrateK8sServiceIntegration::Project', foreign_key: :project_id
+
+    scope :kubernetes_service_templates, -> do
+      where(category: 'deployment', type: 'KubernetesService', template: true)
+    end
+
+    def api_url
+      parsed_properties['api_url'].presence
+    end
+
+    def ca_pem
+      parsed_properties['ca_pem']
+    end
+
+    def namespace
+      parsed_properties['namespace'].presence
+    end
+
+    def token
+      parsed_properties['token'].presence
+    end
+
+    private
+
+    def parsed_properties
+      @parsed_properties ||= JSON.parse(self.properties)
+    end
+  end
+
+  def up
+    MigrateK8sServiceIntegration::Service.kubernetes_service_templates.find_each do |service|
+      next unless service.api_url && service.token
+
+      MigrateK8sServiceIntegration::Cluster.create!(
+        enabled: service.active,
+        managed: false,
+        name: 'KubernetesService',
+        cluster_type: 'instance_type',
+        provider_type: 'user',
+        platform_type: 'kubernetes',
+        platform_kubernetes_attributes: {
+          api_url: service.api_url,
+          ca_cert: service.ca_pem,
+          namespace: service.namespace,
+          token: service.token
+        }
+      )
+    end
+  end
+
+  def down
+    # It is not possible to tell which instance-level clusters were created by
+    # this migration. The original data is intentionally left intact.
+  end
+end

spec/migrations/migrate_k8s_service_integration_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+require Rails.root.join('db', 'post_migrate', '20190517153211_migrate_k8s_service_integration.rb')
+
+describe MigrateK8sServiceIntegration, :migration do
+  context 'template service' do
+    context 'with namespace' do
+      let!(:service) do
+        MigrateK8sServiceIntegration::Service.create!(
+          active: true,
+          template: true,
+          category: 'deployment',
+          type: 'KubernetesService',
+          properties: "{\"namespace\":\"prod\",\"api_url\":\"https://sample.kubernetes.com\",\"ca_pem\":\"ca_pem-sample\",\"token\":\"token-sample\"}"
+        )
+      end
+
+      let(:cluster) { MigrateK8sServiceIntegration::Cluster.instance_type.last! }
+      let(:platform) { cluster.platform_kubernetes }
+
+      it 'migrates the KubernetesService template to Platform::Kubernetes' do
+        expect { migrate! }.to change { MigrateK8sServiceIntegration::Cluster.count }.by(1)
+
+        expect(cluster).to be_enabled
+        expect(cluster).to be_user
+        expect(cluster).not_to be_managed
+        expect(cluster.environment_scope).to eq('*')
+        expect(platform.api_url).to eq('https://sample.kubernetes.com')
+        expect(platform.ca_cert).to eq('ca_pem-sample')
+        expect(platform.namespace).to eq('prod')
+        expect(platform.token).to eq('token-sample')
+      end
+    end
+
+    context 'without namespace' do
+      let!(:service) do
+        MigrateK8sServiceIntegration::Service.create!(
+          active: true,
+          template: true,
+          category: 'deployment',
+          type: 'KubernetesService',
+          properties: "{\"namespace\":\"\",\"api_url\":\"https://sample.kubernetes.com\",\"ca_pem\":\"ca_pem-sample\",\"token\":\"token-sample\"}"
+        )
+      end
+
+      let(:cluster) { MigrateK8sServiceIntegration::Cluster.instance_type.last! }
+      let(:platform) { cluster.platform_kubernetes }
+
+      it 'migrates the KubernetesService template to Platform::Kubernetes' do
+        expect { migrate! }.to change { MigrateK8sServiceIntegration::Cluster.count }.by(1)
+
+        expect(cluster).to be_enabled
+        expect(cluster).to be_user
+        expect(cluster).not_to be_managed
+        expect(cluster.environment_scope).to eq('*')
+        expect(platform.api_url).to eq('https://sample.kubernetes.com')
+        expect(platform.ca_cert).to eq('ca_pem-sample')
+        expect(platform.namespace).to be_nil
+        expect(platform.token).to eq('token-sample')
+      end
+    end
+
+    context 'with nullified parameters' do
+      let!(:service) do
+        MigrateK8sServiceIntegration::Service.create!(
+          active: true,
+          template: true,
+          category: 'deployment',
+          type: 'KubernetesService',
+          properties: "{}"
+        )
+      end
+
+      it 'does not migrate the KubernetesService' do
+        expect { migrate! }.not_to change { MigrateK8sServiceIntegration::Cluster.count }
+      end
+    end
+
+    context 'when disabled' do
+      let!(:service) do
+        MigrateK8sServiceIntegration::Service.create!(
+          active: false,
+          template: true,
+          category: 'deployment',
+          type: 'KubernetesService',
+          properties: "{\"namespace\":\"prod\",\"api_url\":\"https://sample.kubernetes.com\",\"ca_pem\":\"ca_pem-sample\",\"token\":\"token-sample\"}"
+        )
+      end
+
+      let(:cluster) { MigrateK8sServiceIntegration::Cluster.instance_type.last! }
+      let(:platform) { cluster.platform_kubernetes }
+
+      it 'migrates the KubernetesService template to Platform::Kubernetes' do
+        expect { migrate! }.to change { MigrateK8sServiceIntegration::Cluster.count }.by(1)
+
+        expect(cluster).not_to be_enabled
+        expect(cluster).to be_user
+        expect(cluster).not_to be_managed
+        expect(cluster.environment_scope).to eq('*')
+        expect(platform.api_url).to eq('https://sample.kubernetes.com')
+        expect(platform.ca_cert).to eq('ca_pem-sample')
+        expect(platform.namespace).to eq('prod')
+        expect(platform.token).to eq('token-sample')
+      end
+    end
+  end
+
+  context 'non-template service' do
+    let!(:service) do
+      MigrateK8sServiceIntegration::Service.create!(
+        active: true,
+        template: false,
+        category: 'deployment',
+        type: 'KubernetesService',
+        properties: "{\"namespace\":\"prod\",\"api_url\":\"https://sample.kubernetes.com\",\"ca_pem\":\"ca_pem-sample\",\"token\":\"token-sample\"}"
+      )
+    end
+
+    it 'does not migrate the KubernetesService' do
+      expect { migrate! }.not_to change { MigrateK8sServiceIntegration::Cluster.count }
+    end
+  end
+end