Add uvicorn and web sockets for Django 3

* Add use_async option to cookiecutter.json
* Add websocket configuration

cookiecutter.json

@@ -44,6 +44,7 @@
     "SparkPost",
     "Other SMTP"
   ],
+  "use_async": "n",
   "use_drf": "n",
   "custom_bootstrap_compilation": "n",
   "use_compressor": "n",

docs/project-generation-options.rst

@@ -83,6 +83,9 @@ mail_service:
     8. SparkPost_
     9. `Other SMTP`_
 
+use_async:
+    Indicates whether the project should use web sockets with Uvicorn + Gunicorn.
+
 use_drf:
     Indicates whether the project should be configured to use `Django Rest Framework`_.
 

hooks/post_gen_project.py

@@ -101,6 +101,15 @@ def remove_celery_files():
         os.remove(file_name)
 
 
+def remove_async_files():
+    file_names = [
+        os.path.join("config", "asgi.py"),
+        os.path.join("config", "websocket.py"),
+    ]
+    for file_name in file_names:
+        os.remove(file_name)
+
+
 def remove_dottravisyml_file():
     os.remove(".travis.yml")
 
@@ -367,6 +376,9 @@ def main():
     if "{{ cookiecutter.use_drf }}".lower() == "n":
         remove_drf_starter_files()
 
+    if "{{ cookiecutter.use_async }}".lower() == "n":
+        remove_async_files()
+
     print(SUCCESS + "Project initialized, keep up the good work!" + TERMINATOR)
 
 

tests/test_cookiecutter_generation.py

@@ -73,6 +73,8 @@ SUPPORTED_COMBINATIONS = [
     {"cloud_provider": "GCP", "mail_service": "SparkPost"},
     {"cloud_provider": "GCP", "mail_service": "Other SMTP"},
     # Note: cloud_providers GCP and None with mail_service Amazon SES is not supported
+    {"use_async", "y"},
+    {"use_async", "n"},
     {"use_drf": "y"},
     {"use_drf": "n"},
     {"js_task_runner": "None"},

{{cookiecutter.project_slug}}/compose/local/django/start

@@ -6,4 +6,8 @@ set -o nounset
 
 
 python manage.py migrate
+{%- if cookiecutter.use_async %}
+/usr/local/bin/uvicorn config.asgi --bind 0.0.0.0:5000 --chdir=/app
+{%- else %}
 python manage.py runserver_plus 0.0.0.0:8000
+{% endif %}

{{cookiecutter.project_slug}}/compose/production/django/start

@@ -27,4 +27,8 @@ if compress_enabled; then
   python /app/manage.py compress
 fi
 {%- endif %}
+{% if cookiecutter.use_async %}
+/usr/local/bin/uvicorn config.asgi --bind 0.0.0.0:5000 --chdir=/app
+{% else %}
 /usr/local/bin/gunicorn config.wsgi --bind 0.0.0.0:5000 --chdir=/app
+{%- endif %}

{{cookiecutter.project_slug}}/config/asgi.py

@@ -0,0 +1,41 @@
+"""
+ASGI config for {{ cookiecutter.project_name }} project.
+
+It exposes the ASGI callable as a module-level variable named ``application``.
+
+For more information on this file, see
+https://docs.djangoproject.com/en/dev/howto/deployment/asgi/
+"""
+import os
+import sys
+from pathlib import Path
+
+from django.core.asgi import get_asgi_application
+from .websocket import websocket_application
+
+# This allows easy placement of apps within the interior
+# {{ cookiecutter.project_slug }} directory.
+app_path = Path(__file__).parents[1].resolve()
+sys.path.append(str(app_path / "{{ cookiecutter.project_slug }}"))
+# We defer to a DJANGO_SETTINGS_MODULE already in the environment. This breaks
+# if running multiple sites in the same mod_wsgi process. To fix this, use
+# mod_wsgi daemon mode with each site in its own daemon process, or use
+# os.environ["DJANGO_SETTINGS_MODULE"] = "config.settings.production"
+os.environ.setdefault("DJANGO_SETTINGS_MODULE", "config.settings.production")
+
+# This application object is used by any ASGI server configured to use this
+# file. This includes Django's development server, if the ASGI_APPLICATION
+# setting points here.
+django_application = get_asgi_application()
+# Apply ASGI middleware here.
+# from helloworld.asgi import HelloWorldApplication
+# application = HelloWorldApplication(application)
+
+
+async def application(scope, receive, send):
+    if scope['type'] == 'http':
+        await django_application(scope, receive, send)
+    elif scope['type'] == 'websocket':
+        await websocket_application(scope, receive, send)
+    else:
+        raise NotImplementedError(f"Unknown scope type {scope['type']}")

{{cookiecutter.project_slug}}/config/websocket.py

@@ -0,0 +1,18 @@
+async def websocket_application(scope, receive, send):
+    while True:
+        event = await receive()
+
+        if event['type'] == 'websocket.connect':
+            await send({
+                'type': 'websocket.accept'
+            })
+
+        if event['type'] == 'websocket.disconnect':
+            break
+
+        if event['type'] == 'websocket.receive':
+            if event['text'] == 'ping':
+                await send({
+                    'type': 'websocket.send',
+                    'text': 'pong!'
+                })

{{cookiecutter.project_slug}}/requirements/base.txt

@@ -16,6 +16,9 @@ django-celery-beat==2.0.0  # https://github.com/celery/django-celery-beat
 flower==0.9.3  # https://github.com/mher/flower
 {%- endif %}
 {%- endif %}
+{%- if cookiecutter.use_async %}
+uvicorn==0.11.3  # https://github.com/encode/uvicorn
+{%- endif %}
 
 # Django
 # ------------------------------------------------------------------------------