Merge branch 'add-email-subject-suffix' into 'master'

Add configurable email subject suffix

## Why was this MR needed?

I noticed that there is a commit 44ab156e 3 years ago which removes email subject prefix

actually we do need an special part of the email subject which makes the email subject easy to identify

we just need to make it configurable rather than remove it.

See merge request !6172

9 files changed, 36 insertions, 11 deletions

diff --git a/CHANGELOG b/CHANGELOG
index 7ffc74f4ec0..606e6380c41 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -19,6 +19,7 @@ v 8.13.0 (unreleased)
   - Add word-wrap to issue title on issue and milestone boards (ClemMakesApps)
   - Fix robots.txt disallowing access to groups starting with "s" (Matt Harrison)
   - Close open merge request without source project (Katarzyna Kobierska Ula Budziszewska)
+  - Add configurable email subject suffix (Fu Xu)
   - Use a ConnectionPool for Rails.cache on Sidekiq servers
   - Replace `alias_method_chain` with `Module#prepend`
   - Enable GitLab Import/Export for non-admin users.
diff --git a/app/mailers/devise_mailer.rb b/app/mailers/devise_mailer.rb
index 415f6e12885..f7ed61625f4 100644
--- a/app/mailers/devise_mailer.rb
+++ b/app/mailers/devise_mailer.rb
@@ -3,4 +3,12 @@ class DeviseMailer < Devise::Mailer
   default reply_to: Gitlab.config.gitlab.email_reply_to
 
   layout 'devise_mailer'
+
+  protected
+
+  def subject_for(key)
+    subject = super
+    subject << " | #{Gitlab.config.gitlab.email_subject_suffix}" if Gitlab.config.gitlab.email_subject_suffix.present?
+    subject
+  end
 end
diff --git a/app/mailers/emails/members.rb b/app/mailers/emails/members.rb
index 45311690293..7b617b359ea 100644
--- a/app/mailers/emails/members.rb
+++ b/app/mailers/emails/members.rb
@@ -45,7 +45,7 @@ module Emails
       @token = token
 
       mail(to: member.invite_email,
-           subject: "Invitation to join the #{member_source.human_name} #{member_source.model_name.singular}")
+           subject: subject("Invitation to join the #{member_source.human_name} #{member_source.model_name.singular}"))
     end
 
     def member_invite_accepted_email(member_source_type, member_id)
diff --git a/app/mailers/notify.rb b/app/mailers/notify.rb
index 29f1c527776..2444702104e 100644
--- a/app/mailers/notify.rb
+++ b/app/mailers/notify.rb
@@ -92,6 +92,7 @@ class Notify < BaseMailer
     subject = ""
     subject << "#{@project.name} | " if @project
     subject << extra.join(' | ') if extra.present?
+    subject << " | #{Gitlab.config.gitlab.email_subject_suffix}" if Gitlab.config.gitlab.email_subject_suffix.present?
     subject
   end
 
diff --git a/config/gitlab.yml.example b/config/gitlab.yml.example
index 1470a6e2550..a79356923b2 100644
--- a/config/gitlab.yml.example
+++ b/config/gitlab.yml.example
@@ -70,6 +70,7 @@ production: &base
     email_from: example@example.com
     email_display_name: GitLab
     email_reply_to: noreply@example.com
+    email_subject_suffix: ''
 
     # Email server smtp settings are in config/initializers/smtp_settings.rb.sample
 
diff --git a/config/initializers/1_settings.rb b/config/initializers/1_settings.rb
index 195108b921b..c5ed2162c92 100644
--- a/config/initializers/1_settings.rb
+++ b/config/initializers/1_settings.rb
@@ -186,6 +186,7 @@ Settings.gitlab['email_enabled'] ||= true if Settings.gitlab['email_enabled'].ni
 Settings.gitlab['email_from'] ||= ENV['GITLAB_EMAIL_FROM'] || "gitlab@#{Settings.gitlab.host}"
 Settings.gitlab['email_display_name'] ||= ENV['GITLAB_EMAIL_DISPLAY_NAME'] || 'GitLab'
 Settings.gitlab['email_reply_to'] ||= ENV['GITLAB_EMAIL_REPLY_TO'] || "noreply@#{Settings.gitlab.host}"
+Settings.gitlab['email_subject_suffix'] ||= ENV['GITLAB_EMAIL_SUBJECT_SUFFIX'] || ""
 Settings.gitlab['base_url']   ||= Settings.send(:build_base_gitlab_url)
 Settings.gitlab['url']        ||= Settings.send(:build_gitlab_url)
 Settings.gitlab['user']       ||= 'git'
diff --git a/doc/administration/environment_variables.md b/doc/administration/environment_variables.md
index 7f53915a4d7..b4a953d1ccc 100644
--- a/doc/administration/environment_variables.md
+++ b/doc/administration/environment_variables.md
@@ -13,15 +13,17 @@ override certain values.
 
 Variable | Type | Description
 -------- | ---- | -----------
-`GITLAB_ROOT_PASSWORD`      | string | Sets the password for the `root` user on installation
-`GITLAB_HOST`               | string | The full URL of the GitLab server (including `http://` or `https://`)
-`RAILS_ENV`                 | string | The Rails environment; can be one of `production`, `development`, `staging` or `test`
-`DATABASE_URL`              | string | The database URL; is of the form: `postgresql://localhost/blog_development`
-`GITLAB_EMAIL_FROM`         | string | The e-mail address used in the "From" field in e-mails sent by GitLab
-`GITLAB_EMAIL_DISPLAY_NAME` | string | The name used in the "From" field in e-mails sent by GitLab
-`GITLAB_EMAIL_REPLY_TO`     | string | The e-mail address used in the "Reply-To" field in e-mails sent by GitLab
-`GITLAB_UNICORN_MEMORY_MIN` | integer | The minimum memory threshold (in bytes) for the Unicorn worker killer
-`GITLAB_UNICORN_MEMORY_MAX` | integer | The maximum memory threshold (in bytes) for the Unicorn worker killer
+`GITLAB_ROOT_PASSWORD`        | string  | Sets the password for the `root` user on installation
+`GITLAB_HOST`                 | string  | The full URL of the GitLab server (including `http://` or `https://`)
+`RAILS_ENV`                   | string  | The Rails environment; can be one of `production`, `development`, `staging` or `test`
+`DATABASE_URL`                | string  | The database URL; is of the form: `postgresql://localhost/blog_development`
+`GITLAB_EMAIL_FROM`           | string  | The e-mail address used in the "From" field in e-mails sent by GitLab
+`GITLAB_EMAIL_DISPLAY_NAME`   | string  | The name used in the "From" field in e-mails sent by GitLab
+`GITLAB_EMAIL_REPLY_TO`       | string  | The e-mail address used in the "Reply-To" field in e-mails sent by GitLab
+`GITLAB_EMAIL_REPLY_TO`       | string  | The e-mail address used in the "Reply-To" field in e-mails sent by GitLab
+`GITLAB_EMAIL_SUBJECT_SUFFIX` | string  | The e-mail subject suffix used in e-mails sent by GitLab
+`GITLAB_UNICORN_MEMORY_MIN`   | integer | The minimum memory threshold (in bytes) for the Unicorn worker killer
+`GITLAB_UNICORN_MEMORY_MAX`   | integer | The maximum memory threshold (in bytes) for the Unicorn worker killer
 
 ## Complete database variables
 
diff --git a/spec/mailers/notify_spec.rb b/spec/mailers/notify_spec.rb
index cd8578b6f49..0e4130e8a3a 100644
--- a/spec/mailers/notify_spec.rb
+++ b/spec/mailers/notify_spec.rb
@@ -831,6 +831,7 @@ describe Notify do
     let(:user) { create(:user, email: 'old-email@mail.com') }
 
     before do
+      stub_config_setting(email_subject_suffix: 'A Nice Suffix')
       perform_enqueued_jobs do
         user.email = "new-email@mail.com"
         user.save
@@ -847,7 +848,7 @@ describe Notify do
     end
 
     it 'has the correct subject' do
-      is_expected.to have_subject "Confirmation instructions"
+      is_expected.to have_subject /^Confirmation instructions/
     end
 
     it 'includes a link to the site' do
diff --git a/spec/mailers/shared/notify.rb b/spec/mailers/shared/notify.rb
index 5c9851f14c7..3956d05060b 100644
--- a/spec/mailers/shared/notify.rb
+++ b/spec/mailers/shared/notify.rb
@@ -37,6 +37,16 @@ shared_examples 'an email sent from GitLab' do
     reply_to = subject.header[:reply_to].addresses
     expect(reply_to).to eq([gitlab_sender_reply_to])
   end
+
+  context 'when custom suffix for email subject is set' do
+    before do
+      stub_config_setting(email_subject_suffix: 'A Nice Suffix')
+    end
+
+    it 'ends the subject with the suffix' do
+      is_expected.to have_subject /\ \| A Nice Suffix$/
+    end
+  end
 end
 
 shared_examples 'an email that contains a header with author username' do