[change] Improved password expiration warning email #367

Closes #367

openwisp_users/accounts/templates/account/email/password_expiration_message.html

@@ -0,0 +1,5 @@
+{% load i18n %}
+
+<p>{% blocktrans with expiry_date=expiry_date|date:"Y-m-d" %}We inform you that the password for your account {{ username }} will expire in 7 days, precisely on {{ expiry_date }}.{% endblocktrans %}<p>
+
+<p>{% trans "Kindly proceed with updating your password by clicking on the button below." %}<p>

openwisp_users/accounts/templates/account/email/password_expiration_message.txt

@@ -0,0 +1,5 @@
+{% load i18n %}
+
+{% blocktrans with expiry_date=expiry_date|date:"Y-m-d" %}We inform you that the password for your account {{ username }} will expire in 7 days, precisely on {{ expiry_date }}.{% endblocktrans %}
+
+{% trans "Kindly proceed with updating your password by clicking on the button below." %}

openwisp_users/tasks.py

@@ -1,8 +1,11 @@
+from time import sleep
+
 from celery import shared_task
 from django.contrib.auth import get_user_model
 from django.contrib.auth.hashers import UNUSABLE_PASSWORD_PREFIX
 from django.contrib.sites.models import Site
 from django.db.models import Q
+from django.template.loader import render_to_string
 from django.urls import reverse
 from django.utils.timezone import now, timedelta
 from django.utils.translation import gettext_lazy as _
@@ -49,11 +52,18 @@ def password_expiration_email():
         )
         .filter(query)
     )
+    email_counts = 0
     for user in qs.iterator():
         send_email(
-            subject=_('Your password is about to expire'),
-            body_text=_('Your password is about to expire in 7 days'),
-            body_html=_('You password is about to expire in 7 days.'),
+            subject=_('Action Required: Password Expiry Notice'),
+            body_text=render_to_string(
+                'account/email/password_expiration_message.txt',
+                context={'username': user.username, 'expiry_date': expiry_date},
+            ).strip(),
+            body_html=render_to_string(
+                'account/email/password_expiration_message.html',
+                context={'username': user.username, 'expiry_date': expiry_date},
+            ).strip(),
             recipients=[user.email],
             extra_context={
                 'call_to_action_url': 'https://{0}{1}'.format(
@@ -63,3 +73,10 @@ def password_expiration_email():
                 'call_to_action_text': _('Change password'),
             },
         )
+        # Avoid overloading the SMTP server by sending multiple
+        # emails continuously.
+        if email_counts > 10:
+            email_counts = 0
+            sleep(10)
+        else:
+            email_counts += 1

openwisp_users/tests/test_models.py

@@ -428,12 +428,43 @@ def test_password_expiration_mail(self):
                 password_updated=user_expiry_date
             )
             password_expiration_email.delay()
+            formatted_expiry_date = (now() + timedelta(days=7)).strftime('%Y-%m-%d')
             self.assertEqual(len(mail.outbox), 1)
             email = mail.outbox.pop()
             self.assertEqual(email.to, [verified_email_user.email])
-            self.assertEqual(email.subject, 'Your password is about to expire')
+            self.assertEqual(email.subject, 'Action Required: Password Expiry Notice')
+            self.assertEqual(
+                email.body,
+                'We inform you that the password for your account tester will expire'
+                f' in 7 days, precisely on {formatted_expiry_date}.\n\n'
+                'Kindly proceed with updating your password by clicking on the'
+                ' button below.',
+            )
+            self.assertIn(
+                '<p>We inform you that the password for your account tester will expire'
+                f' in 7 days, precisely on {formatted_expiry_date}.<p>\n\n<p>',
+                email.alternatives[0][0],
+            )
+            self.assertIn(
+                'Kindly proceed with updating your password by clicking on the button'
+                ' below.<p>',
+                email.alternatives[0][0],
+            )
             self.assertNotEqual(email.to, [unverified_email_user.email])
 
+    @patch.object(app_settings, 'USER_PASSWORD_EXPIRATION', 30)
+    @patch('openwisp_users.tasks.sleep')
+    def test_password_expiration_mail_sleep(self, mocked_sleep):
+        user_expiry_date = now().today() - timedelta(
+            days=(app_settings.USER_PASSWORD_EXPIRATION - 7)
+        )
+        for i in range(12):
+            self._create_user(username=f'user{i}', email=f'user{i}@example.com')
+        EmailAddress.objects.update(verified=True)
+        User.objects.update(password_updated=user_expiry_date)
+        password_expiration_email.delay()
+        mocked_sleep.assert_called_with(10)
+
     @patch.object(app_settings, 'USER_PASSWORD_EXPIRATION', 0)
     @patch.object(app_settings, 'STAFF_USER_PASSWORD_EXPIRATION', 0)
     def test_password_expiration_mail_settings_disabled(self):