Wagtail on Lambda with RDS

wagtail-zappa-rds.md

Wagtail on AWS Lambda, with Zappa and RDS

Install Wagtail and Zappa, and create an empty site:

pip install wagtail zappa zappa-django-utils
pip install pip==9.0.3 # see https://github.com/Miserlou/Zappa/issues/1471
wagtail start zappa_rds

Set up Zappa. Accept the defaults, but set the project settings to zappa_rds.settings.dev. Make a note of your bucket name.

cd zappa_rds
zappa init

Allow all hosts for now, and include zappa_django_utils in your INSTALLED_APPS:

echo -en "\nALLOWED_HOSTS = ['*']" >> zappa_rds/settings/dev.py
echo -en "\nINSTALLED_APPS += ('zappa_django_utils',)" >> zappa_rds/settings/base.py

Now create a PostgreSQL instance in the RDS console, and call it wagtail-zappa-rds. Make sure it is in the same region that your Lambda will be deployed to (check "aws_region" in your zappa_settings.json). Make it publically accessible for now, but use a strong password. Create a database named wagtail_zappa_db. When it's ready, update zappa_rds/settings/dev.py with

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'wagtail_zappa_db',
        'USER': 'your-username',
        'PASSWORD': 'your-password',
        'HOST': 'your-endpoint',
        'PORT': '5432',
    }
}

Install pyscopg2: pip install psycopg2

Deploy the site with zappa deploy dev. Zappa may create a new security group for your RDS instance. Edit this to allow all inbound traffic. Then migrate, and create an admin user:

zappa manage dev migrate
zappa manage dev create_admin_user

Set up static files:

pip install django-storages boto

Add and configure django-storages, in settings/zappa_rds/dev.py:

INSTALLED_APPS += ('storages',)
# use the bucket that was created in `zappa init`
AWS_STORAGE_BUCKET_NAME = 'your-bucket-name'
AWS_S3_CUSTOM_DOMAIN = '%s.s3.amazonaws.com' % AWS_STORAGE_BUCKET_NAME
STATIC_URL = "https://%s/" % AWS_S3_CUSTOM_DOMAIN
STATICFILES_STORAGE = 'storages.backends.s3boto.S3BotoStorage'
# Don't do this! It's convenient but insecure to use the same 
# bucket for static files and media.
DEFAULT_FILE_STORAGE = 'storages.backends.s3boto.S3BotoStorage'

Update and collect static.

zappa update dev
zappa manage dev "collectstatic --noinput"

Fonts probably won't work until you set a CORS policy on your bucket. Go to your S3 bucket properties, and under "Permissions", click on "Add CORS Configuration", and replace the contents with:

<?xml version="1.0" encoding="UTF-8"?>
<CORSConfiguration xmlns="http://s3.amazonaws.com/doc/2006-03-01/">
  <CORSRule>
    <AllowedOrigin>*</AllowedOrigin>
    <AllowedMethod>GET</AllowedMethod>
    <AllowedMethod>HEAD</AllowedMethod>
  </CORSRule>
</CORSConfiguration>