Merge pull request #8404 from mfo/US/force-email-delivery

Us/force important email delivery

app/controllers/manager/safe_mailers_controller.rb

@@ -0,0 +1,4 @@
+module Manager
+  class SafeMailersController < Manager::ApplicationController
+  end
+end

app/dashboards/safe_mailer_dashboard.rb

@@ -0,0 +1,43 @@
+require "administrate/base_dashboard"
+
+class SafeMailerDashboard < Administrate::BaseDashboard
+  # ATTRIBUTE_TYPES
+  # a hash that describes the type of each of the model's fields.
+  #
+  # Each different type represents an Administrate::Field object,
+  # which determines how the attribute is displayed
+  # on pages throughout the dashboard.
+  ATTRIBUTE_TYPES = {
+    id: Field::Number,
+    created_at: Field::DateTime,
+    updated_at: Field::DateTime,
+    forced_delivery_method: Field::Enum
+  }.freeze
+
+  # COLLECTION_ATTRIBUTES
+  # an array of attributes that will be displayed on the model's index page.
+  #
+  # By default, it's limited to four items to reduce clutter on index pages.
+  # Feel free to add, remove, or rearrange items.
+  COLLECTION_ATTRIBUTES = [
+    :id,
+    :created_at,
+    :updated_at,
+    :forced_delivery_method
+  ].freeze
+
+  # SHOW_PAGE_ATTRIBUTES
+  # an array of attributes that will be displayed on the model's show page.
+  SHOW_PAGE_ATTRIBUTES = [
+    :created_at,
+    :updated_at,
+    :forced_delivery_method
+  ].freeze
+
+  # FORM_ATTRIBUTES
+  # an array of attributes that will be displayed
+  # on the model's form (`new` and `edit`) pages.
+  FORM_ATTRIBUTES = [
+    :forced_delivery_method
+  ].freeze
+end

app/lib/balancer_delivery_method.rb

@@ -14,6 +14,7 @@
 #
 # Be sure to restart your server when you modify this file.
 class BalancerDeliveryMethod
+  FORCE_DELIVERY_METHOD_HEADER = 'X-deliver-with'
   # Allows configuring the random number generator used for selecting a delivery method,
   # mostly for testing purposes.
   mattr_accessor :random, default: Random.new
@@ -39,7 +40,13 @@ class BalancerDeliveryMethod
 
   private
 
+  def force_delivery_method?(mail)
+    @delivery_methods.keys.map(&:to_s).include?(mail[FORCE_DELIVERY_METHOD_HEADER]&.value)
+  end
+
   def delivery_method(mail)
+    return mail[FORCE_DELIVERY_METHOD_HEADER].value.to_sym if force_delivery_method?(mail)
+
     @delivery_methods
       .flat_map { |delivery_method, weight| [delivery_method] * weight }
       .sample(random: self.class.random)

app/mailers/devise_user_mailer.rb

@@ -5,6 +5,7 @@ class DeviseUserMailer < Devise::Mailer
   include Devise::Controllers::UrlHelpers # Optional. eg. `confirmation_url`
   include MailerMonitoringConcern
   layout 'mailers/layout'
+  before_action :add_delivery_method, if: :forced_delivery?
 
   def template_paths
     ['devise_mailer']
@@ -16,4 +17,12 @@ class DeviseUserMailer < Devise::Mailer
     @prefill_token = opts[:prefill_token]
     super
   end
+
+  def add_delivery_method
+    headers[BalancerDeliveryMethod::FORCE_DELIVERY_METHOD_HEADER] = SafeMailer.forced_delivery_method
+  end
+
+  def forced_delivery?
+    SafeMailer.forced_delivery_method.present?
+  end
 end

app/models/safe_mailer.rb

@@ -0,0 +1,20 @@
+# == Schema Information
+#
+# Table name: safe_mailers
+#
+#  id                     :bigint           not null, primary key
+#  forced_delivery_method :string
+#  created_at             :datetime         not null
+#  updated_at             :datetime         not null
+#
+class SafeMailer < ApplicationRecord
+  before_create do
+    raise if SafeMailer.count == 1
+  end
+
+  enum forced_delivery_method: Rails.application.config.action_mailer&.balancer_settings&.keys&.map(&:to_s) || []
+
+  def self.forced_delivery_method
+    first&.forced_delivery_method
+  end
+end

config/environments/development.rb

@@ -1,4 +1,5 @@
 require "active_support/core_ext/integer/time"
+require Rails.root.join("app/lib/balancer_delivery_method")
 
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
@@ -76,7 +77,12 @@ Rails.application.configure do
   config.assets.raise_runtime_errors = true
 
   # Action Mailer settings
-  config.action_mailer.delivery_method = ENV['HELO_ENABLED'] == 'enabled' ? :helo : :letter_opener
+  ActionMailer::Base.add_delivery_method :balancer, BalancerDeliveryMethod
+  config.action_mailer.balancer_settings = {
+    helo: ENV['HELO_ENABLED'] == 'enabled' ? 100 : 0,
+      letter_opener: ENV['HELO_ENABLED'] == 'enabled' ? 0 : 100
+  }
+  config.action_mailer.delivery_method = :balancer
 
   config.action_mailer.default_url_options = { host: ENV.fetch("APP_HOST") }
   config.action_mailer.asset_host = "http://" + ENV.fetch("APP_HOST")

config/routes.rb

@@ -71,6 +71,7 @@ Rails.application.routes.draw do
     resources :outdated_procedures, only: [:index] do
       patch :bulk_update, on: :collection
     end
+    resources :safe_mailers, only: [:index, :edit, :update, :destroy]
 
     post 'demandes/create_administrateur'
     post 'demandes/refuse_administrateur'

db/migrate/20230110153638_create_safe_mailers.rb

@@ -0,0 +1,9 @@
+class CreateSafeMailers < ActiveRecord::Migration[6.1]
+  def change
+    create_table :safe_mailers do |t|
+      t.string :forced_delivery_method
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -785,6 +785,12 @@ ActiveRecord::Schema.define(version: 2023_01_11_094621) do
     t.index ["procedure_id"], name: "index_refused_mails_on_procedure_id"
   end
 
+  create_table "safe_mailers", force: :cascade do |t|
+    t.datetime "created_at", precision: 6, null: false
+    t.string "forced_delivery_method"
+    t.datetime "updated_at", precision: 6, null: false
+  end
+
   create_table "services", force: :cascade do |t|
     t.bigint "administrateur_id"
     t.text "adresse"

spec/lib/balancer_delivery_method_spec.rb

@@ -5,6 +5,20 @@ RSpec.describe BalancerDeliveryMethod do
     end
   end
 
+  class ImportantEmail < ApplicationMailer
+    before_action :set_x_deliver_with
+
+    def greet(name)
+      mail(to: "smtp_to", from: "smtp_from", body: "Hello #{name}")
+    end
+
+    private
+
+    def set_x_deliver_with
+      headers['X-deliver-with'] = :mock_smtp
+    end
+  end
+
   class TestMail
     def self.deliveries
       @deliveries ||= []
@@ -46,6 +60,7 @@ RSpec.describe BalancerDeliveryMethod do
     ActionMailer::Base.add_delivery_method :balancer, BalancerDeliveryMethod
 
     ExampleMailer.delivery_method = :balancer
+    ImportantEmail.delivery_method = :balancer
   end
 
   context 'when a single delivery method is provided' do
@@ -101,6 +116,35 @@ RSpec.describe BalancerDeliveryMethod do
     end
   end
 
+  context 'SafeMailer.important_email_use_delivery_method is present' do
+    before do
+      allow(SafeMailer).to receive(:important_email_use_delivery_method).and_return(delivery_method)
+      ActionMailer::Base.balancer_settings = { mock_smtp: 10, mock_sendmail: 5 }
+
+      rng_sequence = [3, 14, 1]
+      BalancerDeliveryMethod.random = FixedSequence.new(rng_sequence)
+    end
+
+    after do
+      BalancerDeliveryMethod.random = Random.new
+    end
+
+    context 'known delivery_method & email is important' do
+      let(:delivery_method) { :mock_smtp }
+
+      it 'sends emails given the forced_delivery_method' do
+        mail1 = ImportantEmail.greet('Lucia').deliver_now
+        expect(mail1).to have_been_delivered_using(MockSmtp)
+
+        mail2 = ImportantEmail.greet('Damian').deliver_now
+        expect(mail2).to have_been_delivered_using(MockSmtp)
+
+        mail3 = ImportantEmail.greet('Rahwa').deliver_now
+        expect(mail3).to have_been_delivered_using(MockSmtp)
+      end
+    end
+  end
+
   # Helpers
 
   def have_been_delivered_using(delivery_class)

spec/mailers/devise_user_mailer_spec.rb

@@ -0,0 +1,16 @@
+RSpec.describe DeviseUserMailer, type: :mailer do
+  let(:user) { create(:user) }
+  let(:token) { SecureRandom.hex }
+  describe '.confirmation_instructions' do
+    context 'without SafeMailer configured' do
+      subject { described_class.confirmation_instructions(user, token, opts = {}) }
+      it { expect(subject[BalancerDeliveryMethod::FORCE_DELIVERY_METHOD_HEADER]&.value).to eq(nil) }
+    end
+    context 'with SafeMailer configured' do
+      let(:forced_delivery_method) { :kikoo }
+      before { allow(SafeMailer).to receive(:forced_delivery_method).and_return(forced_delivery_method) }
+      subject { described_class.confirmation_instructions(user, token, opts = {}) }
+      it { expect(subject[BalancerDeliveryMethod::FORCE_DELIVERY_METHOD_HEADER]&.value).to eq(forced_delivery_method.to_s) }
+    end
+  end
+end