Send a notification email on mirror update errors

The email is sent to project maintainers containing the last mirror
update error. This will allow maintainers to set alarms and react
accordingly.

3 files changed, 21 insertions, 0 deletions

diff --git a/app/mailers/emails/remote_mirrors.rb b/app/mailers/emails/remote_mirrors.rb
new file mode 100644
index 00000000000..2018eb7260b
--- /dev/null
+++ b/app/mailers/emails/remote_mirrors.rb
@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+module Emails
+  module RemoteMirrors
+    def remote_mirror_update_failed_email(remote_mirror_id, recipient_id)
+      @remote_mirror = RemoteMirrorFinder.new(id: remote_mirror_id).execute
+      @project = @remote_mirror.project
+
+      mail(to: recipient(recipient_id), subject: subject('Remote mirror update failed'))
+    end
+  end
+end
diff --git a/app/mailers/notify.rb b/app/mailers/notify.rb
index 88ad4c3e893..099ad779aa5 100644
--- a/app/mailers/notify.rb
+++ b/app/mailers/notify.rb
@@ -13,6 +13,7 @@ class Notify < BaseMailer
   include Emails::Pipelines
   include Emails::Members
   include Emails::AutoDevops
+  include Emails::RemoteMirrors
 
   helper MergeRequestsHelper
   helper DiffHelper
diff --git a/app/mailers/previews/notify_preview.rb b/app/mailers/previews/notify_preview.rb
index e7e8d96eca4..2ac4610967d 100644
--- a/app/mailers/previews/notify_preview.rb
+++ b/app/mailers/previews/notify_preview.rb
@@ -145,6 +145,10 @@ class NotifyPreview < ActionMailer::Preview
     Notify.autodevops_disabled_email(pipeline, user.email).message
   end
 
+  def remote_mirror_update_failed_email
+    Notify.remote_mirror_update_failed_email(remote_mirror.id, user.id).message
+  end
+
   private
 
   def project
@@ -167,6 +171,10 @@ class NotifyPreview < ActionMailer::Preview
     @pipeline = Ci::Pipeline.last
   end
 
+  def remote_mirror
+    @remote_mirror ||= RemoteMirror.last
+  end
+
   def user
     @user ||= User.last
   end