Switch email sending to task queue when available (#15270)

This will mean that CMS notifications will go via the task queue.

The default queue of, well, "default" will be used, which is
one of the queues already being processed by our worker pods: https://github.com/mozilla/bedrock/blob/main/bin/run-worker.sh#L8

At the moment, the Web deployment does not have Redis available to it
so will not have a task queue enabled, and so in turn the
emails that web pods send (eg press requests) will have
no change to their sending pattern

bedrock/settings/base.py

@@ -791,6 +791,7 @@ def get_app_name(hostname):
     "django_extensions",
     "lib.l10n_utils",
     "django_rq",
+    "django_rq_email_backend",
     "mozilla_django_oidc",  # needs to be loaded after django.contrib.auth
 ]
 
@@ -952,8 +953,11 @@ def _is_bedrock_custom_app(app_name):
 # This can be changed to use session once we do add a database.
 MESSAGE_STORAGE = "django.contrib.messages.storage.cookie.CookieStorage"
 
-
-default_email_backend = "django.core.mail.backends.console.EmailBackend" if DEBUG else "django.core.mail.backends.smtp.EmailBackend"
+default_email_backend = "django.core.mail.backends.smtp.EmailBackend"
+if DEBUG:
+    default_email_backend = "django.core.mail.backends.console.EmailBackend"
+elif TASK_QUEUE_AVAILABLE is True:
+    default_email_backend = "django_rq_email_backend.backends.RQEmailBackend"
 
 DEFAULT_FROM_EMAIL = "Mozilla.com <[email protected]>"
 

requirements/dev.txt

@@ -499,6 +499,7 @@ django==4.2.16 \
     #   django-mozilla-product-details
     #   django-permissionedforms
     #   django-rq
+    #   django-rq-email-backend
     #   django-storages
     #   django-taggit
     #   django-treebeard
@@ -572,6 +573,12 @@ django-permissionedforms==0.1 \
 django-rq==2.10.2 \
     --hash=sha256:5fe340e071c141a23ea0859df73c48b0a3df33a851835b2a8f8c4fca7a8b1849 \
     --hash=sha256:d1690b6a409934a0ea23c208ccb00d69477899f8edc61106ce5395c19dcdfb1e
+    # via
+    #   -r requirements/prod.txt
+    #   django-rq-email-backend
+django-rq-email-backend==2.0.0 \
+    --hash=sha256:402ced0d8078a856a684be37206fbfb0a6056c5bfe8a753dd7eec7fcaccca224 \
+    --hash=sha256:4e8a6c6f492f9e78711e6b563c96f7b8feaf17c8737767a30fc68b9833e3b82f
     # via -r requirements/prod.txt
 django-storages[google]==1.14.4 \
     --hash=sha256:69aca94d26e6714d14ad63f33d13619e697508ee33ede184e462ed766dc2a73f \
@@ -2051,6 +2058,7 @@ rq==1.16.2 \
     # via
     #   -r requirements/prod.txt
     #   django-rq
+    #   django-rq-email-backend
 rsa==4.9 \
     --hash=sha256:90260d9058e514786967344d0ef75fa8727eed8a7d2e43ce9f4bcf1b536174f7 \
     --hash=sha256:e38464a49c6c85d7f1351b0126661487a7e0a14a50f1675ec50eb34d4f20ef21

requirements/prod.in

@@ -21,6 +21,7 @@ django-jsonview==2.0.0
 django-memoize==2.3.1
 django-mozilla-product-details==1.0.3
 django-rq==2.10.2
+django-rq-email-backend==2.0.0
 django-storages[google]==1.14.4
 django-waffle==4.1.0
 django-watchman==1.3.0

requirements/prod.txt

@@ -326,6 +326,7 @@ django==4.2.16 \
     #   django-mozilla-product-details
     #   django-permissionedforms
     #   django-rq
+    #   django-rq-email-backend
     #   django-storages
     #   django-taggit
     #   django-treebeard
@@ -393,6 +394,12 @@ django-permissionedforms==0.1 \
 django-rq==2.10.2 \
     --hash=sha256:5fe340e071c141a23ea0859df73c48b0a3df33a851835b2a8f8c4fca7a8b1849 \
     --hash=sha256:d1690b6a409934a0ea23c208ccb00d69477899f8edc61106ce5395c19dcdfb1e
+    # via
+    #   -r requirements/prod.in
+    #   django-rq-email-backend
+django-rq-email-backend==2.0.0 \
+    --hash=sha256:402ced0d8078a856a684be37206fbfb0a6056c5bfe8a753dd7eec7fcaccca224 \
+    --hash=sha256:4e8a6c6f492f9e78711e6b563c96f7b8feaf17c8737767a30fc68b9833e3b82f
     # via -r requirements/prod.in
 django-storages[google]==1.14.4 \
     --hash=sha256:69aca94d26e6714d14ad63f33d13619e697508ee33ede184e462ed766dc2a73f \
@@ -1476,14 +1483,16 @@ rpds-py==0.20.0 \
 rq==1.16.2 \
     --hash=sha256:52e619f6cb469b00e04da74305045d244b75fecb2ecaa4f26422add57d3c5f09 \
     --hash=sha256:5c5b9ad5fbaf792b8fada25cc7627f4d206a9a4455aced371d4f501cc3f13b34
-    # via django-rq
+    # via
+    #   django-rq
+    #   django-rq-email-backend
 rsa==4.9 \
     --hash=sha256:90260d9058e514786967344d0ef75fa8727eed8a7d2e43ce9f4bcf1b536174f7 \
     --hash=sha256:e38464a49c6c85d7f1351b0126661487a7e0a14a50f1675ec50eb34d4f20ef21
     # via google-auth
-s3transfer==0.10.2 \
-    --hash=sha256:0711534e9356d3cc692fdde846b4a1e4b0cb6519971860796e6bc4c7aea00ef6 \
-    --hash=sha256:eca1c20de70a39daee580aef4986996620f365c4e0fda6a86100231d62f1bf69
+s3transfer==0.10.3 \
+    --hash=sha256:263ed587a5803c6c708d3ce44dc4dfedaab4c1a32e8329bab818933d79ddcf5d \
+    --hash=sha256:4f50ed74ab84d474ce614475e0b8d5047ff080810aac5d01ea25231cfc944b0c
     # via boto3
 sentry-processor==0.0.1 \
     --hash=sha256:fd7a30fb57aaf05c01cd04cf7d949c628376b2b55d7a0aaa222efe58a8f122bc