Deployment with Docker

Prerequisites

  • Docker (at least 1.10)
  • Docker Compose (at least 1.6)

Understand the Compose Setup

Before you start, check out the production.yml file in the root of this project. This is where each component of this application gets its configuration from. Notice how it provides configuration for these services:

  • postgres service that runs the database
  • redis for caching
  • caddy as webserver
  • django is the Django project run by gunicorn

If you chose the use_celery option, there are two more services:

  • celeryworker which runs the celery worker process
  • celerybeat which runs the celery beat process

Populate .env With Your Environment Variables

Some of these services rely on environment variables set by you. There is an env.example file in the root directory of this project as a starting point. Add your own variables to the file and rename it to .env. This file won’t be tracked by git by default so you’ll have to make sure to use some other mechanism to copy your secret if you are relying solely on git.

It is highly recommended that before you build your production application, you set your POSTGRES_USER value here. This will create a non-default user for the postgres image. If you do not set this user before building the application, the default user ‘postgres’ will be created, and this user will not be able to create or restore backups.

To obtain logs and information about crashes in a production setup, make sure that you have access to an external Sentry instance (e.g. by creating an account with sentry.io), and set the DJANGO_SENTRY_DSN variable. This should be enough to report crashes to Sentry.

You will probably also need to setup the Mail backend, for example by adding a Mailgun API key and a Mailgun sender domain, otherwise, the account creation view will crash and result in a 500 error when the backend attempts to send an email to the account owner.

HTTPS is on by default

SSL (Secure Sockets Layer) is a standard security technology for establishing an encrypted link between a server and a client, typically in this case, a web server (website) and a browser. Not having HTTPS means that malicious network users can sniff authentication credentials between your website and end users’ browser.

It is always better to deploy a site behind HTTPS and will become crucial as the web services extend to the IoT (Internet of Things). For this reason, we have set up a number of security defaults to help make your website secure:

  • In the .env.example, we have made it simpler for you to change the default Django Admin into a custom name through an environmental variable. This should make it harder to guess the access to the admin panel.
  • If you are not using a subdomain of the domain name set in the project, then remember to put the your staging/production IP address in the DJANGO_ALLOWED_HOSTS environment variable (see Settings) before you deploy your website. Failure to do this will mean you will not have access to your website through the HTTP protocol.
  • Access to the Django admin is set up by default to require HTTPS in production or once live.

HTTPS is configured by default

The Caddy webserver used in the default configuration will get you a valid certificate from Lets Encrypt and update it automatically. All you need to do to enable this is to make sure that your DNS records are pointing to the server Caddy runs on.

You can read more about this here at Automatic HTTPS in the Caddy docs.

Optional: Postgres Data Volume Modifications

Postgres is saving its database files to the postgres_data volume by default. Change that if you want something else and make sure to make backups since this is not done automatically.

Run your app with docker-compose

To get started, pull your code from source control (don’t forget the .env file) and change to your projects root directory.

You’ll need to build the stack first. To do that, run:

docker-compose -f production.yml build

Once this is ready, you can run it with:

docker-compose -f production.yml up

To run a migration, open up a second terminal and run:

docker-compose -f production.yml run django python manage.py migrate

To create a superuser, run:

docker-compose -f production.yml run django python manage.py createsuperuser

If you need a shell, run:

docker-compose -f production.yml run django python manage.py shell

To get an output of all running containers.

To check your logs, run:

docker-compose -f production.yml logs

If you want to scale your application, run:

docker-compose -f production.yml scale django=4
docker-compose -f production.yml scale celeryworker=2

Warning

Don’t run the scale command on postgres, celerybeat, or caddy.

If you have errors, you can always check your stack with docker-compose. Switch to your projects root directory and run:

docker-compose -f production.yml ps

Supervisor Example

Once you are ready with your initial setup, you want to make sure that your application is run by a process manager to survive reboots and auto restarts in case of an error. You can use the process manager you are most familiar with. All it needs to do is to run docker-compose -f production.yml up in your projects root directory.

If you are using supervisor, you can use this file as a starting point:

[program:{{cookiecutter.project_slug}}]
command=docker-compose -f production.yml up
directory=/path/to/{{cookiecutter.project_slug}}
redirect_stderr=true
autostart=true
autorestart=true
priority=10

Place it in /etc/supervisor/conf.d/{{cookiecutter.project_slug}}.conf and run:

supervisorctl reread
supervisorctl start {{cookiecutter.project_slug}}

To get the status, run:

supervisorctl status