Send welcome email to new Cloud subscribers

cloud/email.py

@@ -0,0 +1,33 @@
+import functools
+import logging
+
+import flask
+
+from pillar.auth import UserClass
+
+log = logging.getLogger(__name__)
+
+
+def queue_welcome_mail(user: UserClass):
+    """Queue a welcome email for execution by Celery."""
+    assert user.email
+    log.info('queueing welcome email to %s', user.email)
+
+    subject = 'Welcome to Blender Cloud'
+    render = functools.partial(flask.render_template, subject=subject, user=user)
+    text = render('emails/welcome.txt')
+    html = render('emails/welcome.html')
+
+    from pillar.celery import email_tasks
+    email_tasks.send_email.delay(user.full_name, user.email, subject, text, html)
+
+
+def user_subscription_changed(user: UserClass, *, grant_roles: set, revoke_roles: set):
+    if user.has_cap('subscriber') and 'has_subscription' in grant_roles:
+        log.info('user %s just got a new subscription', user.email)
+        queue_welcome_mail(user)
+
+
+def setup_app(app):
+    from pillar.api.blender_cloud import subscription
+    subscription.user_subscription_updated.connect(user_subscription_changed)