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 docker-compose.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
  • nginx as reverse proxy
  • 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

If you chose the use_letsencrypt option, you also have:

  • certbot which keeps your certs from letsencrypt up-to-date

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.

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 ``ALLOWED_HOSTS``_ environment variable 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. We recommend that you look into setting up the Certbot and Let’s Encrypt Setup mentioned below or another HTTPS certification service.

Optional: nginx-proxy Setup

By default, the application is configured to listen on all interfaces on port 80. If you want to change that, open the docker-compose.yml file and replace 0.0.0.0 with your own ip.

If you are using nginx-proxy to run multiple application stacks on one host, remove the port setting entirely and add VIRTUAL_HOST=example.com to your env file. Here, replace example.com with the value you entered for domain_name.

This pass all incoming requests on nginx-proxy to the nginx service your application is using.

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.

Optional: Certbot and Let’s Encrypt Setup

If you chose use_letsencrypt and will be using certbot for https, you must do the following before running anything with docker-compose:

Replace dhparam.pem.example with a generated dhparams.pem file before running anything with docker-compose. You can generate this on ubuntu or OS X by running the following in the project root:

$ openssl dhparam -out /path/to/project/compose/nginx/dhparams.pem 2048

If you would like to add additional subdomains to your certificate, you must add additional parameters to the certbot command in the docker-compose.yml file:

Replace:

command: bash -c "sleep 6 && certbot certonly -n --standalone -d {{ cookiecutter.domain_name }} --text --agree-tos --email mjsisley@relawgo.com --server https://acme-v01.api.letsencrypt.org/directory --rsa-key-size 4096 --verbose --keep-until-expiring --standalone-supported-challenges http-01"

With:

command: bash -c "sleep 6 && certbot certonly -n --standalone -d {{ cookiecutter.domain_name }} -d www.{{ cookiecutter.domain_name }} -d etc.{{ cookiecutter.domain_name }} --text --agree-tos --email {{ cookiecutter.email }} --server https://acme-v01.api.letsencrypt.org/directory --rsa-key-size 4096 --verbose --keep-until-expiring --standalone-supported-challenges http-01"

Please be cognizant of Certbot/Letsencrypt certificate requests limits when getting this set up. The provide a test server that does not count against the limit while you are getting set up.

The certbot certificates expire after 3 months. If you would like to set up autorenewal of your certificates, the following commands can be put into a bash script:

#!/bin/bash
cd <project directory>
docker-compose run --rm --name certbot certbot bash -c "sleep 6 && certbot certonly --standalone -d {{ cookiecutter.domain_name }} --text --agree-tos --email {{ cookiecutter.email }} --server https://acme-v01.api.letsencrypt.org/directory --rsa-key-size 4096 --verbose --keep-until-expiring --standalone-supported-challenges http-01"
docker exec pearl_nginx_1 nginx -s reload

And then set a cronjob by running crontab -e and placing in it (period can be adjusted as desired):

0 4 * * 1 /path/to/bashscript/renew_certbot.sh

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 build

Once this is ready, you can run it with:

docker-compose up

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

docker-compose run django python manage.py migrate

To create a superuser, run:

docker-compose run django python manage.py createsuperuser

If you need a shell, run:

docker-compose run django python manage.py shell

To get an output of all running containers.

To check your logs, run:

docker-compose logs

If you want to scale your application, run:

docker-compose scale django=4
docker-compose scale celeryworker=2

Warning

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

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

docker-compose 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 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 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