Introduce mail notification

A mail will be sent when a new user registered (this implements #57)
Prepare mail sending by introducing required settings for dev and production, including entries in the matching secrets sample file (this finishes the implementation parts of #69)

dachor/settings.py

@@ -159,3 +159,9 @@
 
 LOGIN_URL = "/accounts/login/"
 LOGIN_REDIRECT_URL = "/intern/"
+
+# Emails
+SEND_MAILS = True
+EMAIL_BACKEND = 'django.core.mail.backends.console.EmailBackend'
+ADMIN_MAILS = ['[email protected]']
+DEFAULT_FROM_EMAIL = '[email protected]'

dachor/settings_production.py

@@ -36,3 +36,21 @@
 }
 
 # TODO: caching
+
+### EMAILS ###
+SEND_MAILS = True
+EMAIL_BACKEND = 'django.core.mail.backends.smtp.EmailBackend'
+
+# Addresses of all admins of this instance that will receive mail notifications
+ADMIN_MAILS = secrets.MAIL_ADMINS
+
+# Address to send from
+SERVER_EMAIL = secrets.MAIL_ADDRESS
+DEFAULT_FROM_EMAIL = SERVER_EMAIL
+
+# SMTP Server Details
+EMAIL_HOST = secrets.MAIL_HOST
+EMAIL_PORT = secrets.MAIL_PORT
+EMAIL_USE_TLS = secrets.MAIL_USE_TLS
+EMAIL_HOST_USER = secrets.MAIL_USER
+EMAIL_HOST_PASSWORD = secrets.MAIL_PASSWORD

dachor/settings_secrets.py.sample

@@ -5,3 +5,14 @@ HOSTS = []
 DB_NAME = ''
 DB_USER = ''
 DB_PASSWORD = ''
+
+# Addresses of all admins of this instance that will receive mail notifications
+MAIL_ADMINS = []
+# Address to send from
+MAIL_SERVER_ADDRESS = ''
+# SMTP Server Details
+MAIL_HOST = ''
+MAIL_PORT = 587
+MAIL_USE_TLS = True
+MAIL_HOST_USER = ''
+MAIL_HOST_PASSWORD = ''

dachor_internal/models.py

@@ -1,10 +1,13 @@
 import datetime
 
+from django.conf import settings
 from django.core.exceptions import ValidationError
+from django.core.mail import EmailMessage
 from django.db import models
 from django.contrib.auth.models import User
 from django.db.models.signals import post_save
 from django.dispatch import receiver
+from django.urls import reverse_lazy
 
 
 def validate_birthday(value):
@@ -77,3 +80,21 @@ def save_user_profile(sender, instance, **kwargs):
         profile.save()
     except Profile.DoesNotExist:
         pass
+
+
+@receiver(post_save, sender=User)
+def user_saved_handler(sender, instance: User, created, **kwargs):
+    """
+    React to user creation by sending a notification mail to the instance admins
+    """
+    if created and settings.SEND_MAILS:
+        host = 'https://' + settings.ALLOWED_HOSTS[0] if len(settings.ALLOWED_HOSTS) > 0 else 'http://127.0.0.1:8000'
+        url = f"{host}{reverse_lazy('admin:auth_user_change', kwargs={'object_id': instance.pk})}"
+
+        mail = EmailMessage(
+            f"[DA!CHOR Webseite] Neuer Benutzer '{instance.username}' angelegt",
+            f"Ein neuer Nutzer {instance.first_name} {instance.last_name} ({instance.username}) hat sich registriert.\n\nFreigeben: {url}",
+            settings.DEFAULT_FROM_EMAIL,
+            settings.ADMIN_MAILS
+        )
+        mail.send(fail_silently=True)