Add annotation model

Add model for annotations relation
along with spec, factory, and associations.

app/models/clusters/cluster.rb

@@ -59,6 +59,7 @@ module Clusters
     has_one_cluster_application :elastic_stack
 
     has_many :kubernetes_namespaces
+    has_many :metrics_dashboard_annotations, class_name: 'Metrics::Dashboard::Annotation', inverse_of: :cluster
 
     accepts_nested_attributes_for :provider_gcp, update_only: true
     accepts_nested_attributes_for :provider_aws, update_only: true

app/models/environment.rb

@@ -18,6 +18,7 @@ class Environment < ApplicationRecord
   has_many :successful_deployments, -> { success }, class_name: 'Deployment'
   has_many :active_deployments, -> { active }, class_name: 'Deployment'
   has_many :prometheus_alerts, inverse_of: :environment
+  has_many :metrics_dashboard_annotations, class_name: 'Metrics::Dashboard::Annotation', inverse_of: :environment
   has_many :self_managed_prometheus_alert_events, inverse_of: :environment
 
   has_one :last_deployment, -> { success.order('deployments.id DESC') }, class_name: 'Deployment'

app/models/metrics/dashboard/annotation.rb

+# frozen_string_literal: true
+
+module Metrics
+  module Dashboard
+    class Annotation < ApplicationRecord
+      self.table_name = 'metrics_dashboard_annotations'
+
+      belongs_to :environment, inverse_of: :metrics_dashboard_annotations
+      belongs_to :cluster, class_name: 'Clusters::Cluster', inverse_of: :metrics_dashboard_annotations
+
+      validates :starting_at, presence: true
+      validates :description, presence: true, length: { maximum: 255 }
+      validates :dashboard_path, presence: true, length: { maximum: 255 }
+      validates :panel_xid, length: { maximum: 255 }
+      validate :single_ownership
+      validate :orphaned_annotation
+
+      private
+
+      def single_ownership
+        return if cluster.nil? ^ environment.nil?
+
+        errors.add(:base, s_("Metrics::Dashboard::Annotation|Annotation can't belong to both a cluster and an environment at the same time"))
+      end
+
+      def orphaned_annotation
+        return if cluster.present? || environment.present?
+
+        errors.add(:base, s_("Metrics::Dashboard::Annotation|Annotation must belong to a cluster or an environment"))
+      end
+    end
+  end
+end

locale/gitlab.pot

@@ -12755,6 +12755,12 @@ msgstr ""
 msgid "Metrics for environment"
 msgstr ""
 
+msgid "Metrics::Dashboard::Annotation|Annotation can't belong to both a cluster and an environment at the same time"
+msgstr ""
+
+msgid "Metrics::Dashboard::Annotation|Annotation must belong to a cluster or an environment"
+msgstr ""
+
 msgid "Metrics|Add metric"
 msgstr ""
 

spec/factories/metrics/dashboard/annotations.rb

+# frozen_string_literal: true
+
+FactoryBot.define do
+  factory :metrics_dashboard_annotation, class: '::Metrics::Dashboard::Annotation' do
+    description { "Dashbaord annoation description" }
+    dashboard_path { "custom_dashbaord.yml" }
+    starting_at { Time.current }
+    environment
+
+    trait :with_cluster do
+      cluster
+      environment { nil }
+    end
+  end
+end

spec/models/clusters/cluster_spec.rb

@@ -27,6 +27,7 @@ describe Clusters::Cluster, :use_clean_rails_memory_store_caching do
   it { is_expected.to have_many(:kubernetes_namespaces) }
   it { is_expected.to have_one(:cluster_project) }
   it { is_expected.to have_many(:deployment_clusters) }
+  it { is_expected.to have_many(:metrics_dashboard_annotations) }
 
   it { is_expected.to delegate_method(:status).to(:provider) }
   it { is_expected.to delegate_method(:status_reason).to(:provider) }

spec/models/environment_spec.rb

@@ -17,6 +17,7 @@ describe Environment, :use_clean_rails_memory_store_caching do
 
   it { is_expected.to belong_to(:project).required }
   it { is_expected.to have_many(:deployments) }
+  it { is_expected.to have_many(:metrics_dashboard_annotations) }
 
   it { is_expected.to delegate_method(:stop_action).to(:last_deployment) }
   it { is_expected.to delegate_method(:manual_actions).to(:last_deployment) }

spec/models/metrics/dashboard/annotation_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+describe Metrics::Dashboard::Annotation do
+  describe 'associations' do
+    it { is_expected.to belong_to(:environment).inverse_of(:metrics_dashboard_annotations) }
+    it { is_expected.to belong_to(:cluster).class_name('Clusters::Cluster').inverse_of(:metrics_dashboard_annotations) }
+  end
+
+  describe 'validation' do
+    it { is_expected.to validate_presence_of(:description) }
+    it { is_expected.to validate_presence_of(:dashboard_path) }
+    it { is_expected.to validate_presence_of(:starting_at) }
+    it { is_expected.to validate_length_of(:dashboard_path).is_at_most(255) }
+    it { is_expected.to validate_length_of(:panel_xid).is_at_most(255) }
+    it { is_expected.to validate_length_of(:description).is_at_most(255) }
+
+    context 'orphaned annotation' do
+      subject { build(:metrics_dashboard_annotation, environment: nil) }
+
+      it { is_expected.not_to be_valid }
+
+      it 'reports error about both missing relations' do
+        subject.valid?
+
+        expect(subject.errors.full_messages).to include(/Annotation must belong to a cluster or an environment/)
+      end
+    end
+
+    context 'environments annotation' do
+      subject { build(:metrics_dashboard_annotation) }
+
+      it { is_expected.to be_valid }
+    end
+
+    context 'clusters annotation' do
+      subject { build(:metrics_dashboard_annotation, :with_cluster) }
+
+      it { is_expected.to be_valid }
+    end
+
+    context 'annotation with shared ownership' do
+      subject { build(:metrics_dashboard_annotation, :with_cluster, environment: build(:environment) ) }
+
+      it 'reports error about both shared ownership' do
+        subject.valid?
+
+        expect(subject.errors.full_messages).to include(/Annotation can't belong to both a cluster and an environment at the same time/)
+      end
+    end
+  end
+end