Impression - The CMS For Email

Source: https://github.com/gregschmit/django-impression

PyPI: https://pypi.org/project/django-impression/

Django Impression is a reusable Django app that provides you with the ability to edit your email templates in a web interface and configure distribution lists if you don't have them configured on your email provider. It also implements a RESTful API so any other web applications you have in your ecosystem can send consistent-looking emails.

The Problem: Email lists and templates for Django projects and other web applications are often kept in source control, requiring developers to edit code when, for example, your marketing guru wants to tweak the layout of one of your emails. They may not want to sift through your backend code to make such changes. Even if they do, you may want to have your email templates accessible over an API so all of your organization's email templates can be centralized.

The Solution: Impression provides the ability to separate your email template system from your source code, by building email templates as model instances. You can still use file-based templates if you would like, and the model templates can even {% extend %} those file-based templates. This allows email templates to be modified in the admin UI by a wider variety of users; not just those who have access to your source code. Impression also exposes a REST API endpoint for sending emails from other web applications, with easy-to-configure access controls. This makes it easier to centralize your email brand and keep things looking awesome and consistent. You can run Impression in an existing project, or you can run it standalone by itself (e.g., impression.example.com).

Key Features:

• Email templates are editable by users in the UI.
• API endpoints allow remote systems to send emails.
• Impression is protected by a system of semi-trust, where you can apply rate limits on the systems which use Impression, and control the content and format of emails.

Architectures

There are a few ways to integrate Impression into an environment:

• Standalone: Impression can be run from a system to serve RESTful requests from your web applications. As long as you use HTTPS, this can be done across the internet. Here are some use cases:
  • You have more than 1 web application operating in your ecosystem and want to centralize your email templating within your organization.
  • You have a fleet of systems in the hands of customers (semi-trusted users) to whom you cannot provide your SMTP details. You want them to be able to request emails to be sent (e.g., for notification systems).
• Integrated: Impression can be mixed in with an existing Django project. A use case could be:
  • A company has a couple people in the marketing department who are wizards with the Bootstrap Email framework; they don't need to have access to the source and they really want to quickly test and push out new designs. Using Impression along with the sleek template editing UI, powered by CodeMirror, they can quickly develop email templates and deploy them without involving the development team.

Installation

$ pip install django-impression

Configuration

Whether you are going to run Impression from your existing project locally, or whether you are going to integrate your existing project with a standalone Impression system affects how you should configure the settings.

There are 2 configuration schemes:

• Local: You wish to send emails from a project that has Impression integrated into it.
• Remote: You wish to send email remotely via the REST API of an Impression instance running in another project. (For our purposes, "Remote" means on another system, or even another project running on the same system, in which case you'll use localhost.)

Local

Add impression to your INSTALLED_APPS, run migrations, and configure some settings:

# This should be your *actual* email backend.
IMPRESSION_EMAIL_BACKEND = "django.core.mail.backends.smtp.EmailBackend"

# this is configured to pass emails to Impression.
EMAIL_BACKEND = "impression.backends.LocalEmailBackend"

To hook the API endpoint /api/send_message into your project for remote systems, just add this entry to your URL dispatcher's urlpatterns list:

path("api/", include("impression.api.urls")),  # includes the send_message endpoint

Remote

For remote systems that will talk to your Impression server over the REST API, use the Impression Client.

Installing as Standalone System

It's a very good idea to setup a dedicated Django application on a server for your organization (then all of your apps can use that system remotely).

To make things really easy, if you have a Docker or Virtual environment, or just wish to spin Impression up on it's own server, you can check out ImpressionOS to deploy Impression as a standalone system. That project provides the ability to configure everything about the system in the Admin UI, and even configure Let's Encrypt certificates to ensure your email API is secure.

Model Configuration

To get familiar with Impression models, here is a quick guide on which models to visit first, in order:

1. Email addresses (the EmailAddress model): You should create email addresses for the email that you will be sending from.
2. Services (the Service model): You should create at least one "default" service. If you permit users to specify the emails that they send to (only for trusted systems!), then those emails will be created on the fly when those messages are created.
3. Templates (the Template model): Go ahead and create a template that adds a footer. Ensure you add {{ body }} somewhere in the body, and {{ subject }} in the subject and the subject/body of the email request will be inserted there. You can then hook it into your Service by editing your service and selecting it under the template field. If you're feeling adventurous, you can use an email template from Bootstrap or Foundation.
4. Now you can either send email with Django's send_mail, and remote systems can use send_mail to reach your Impression server, provided they have followed the configuration instructions above.

Tests

$ python manage.py test