Docker Django

tl;dr

$ git clone [email protected]:erroneousboat/docker-django.git
$ docker-compose up

Now you can access the application at https://localhost and the admin site at https://localhost/admin.

A project to get you started with Docker and Django. This is made to serve as an example for you to hack on, so I don't claim that this is the correct way to setup a system with Django and Docker. Thus, I advice to also look at other projects.

Stack and version numbers used:

Folder structure

$ tree -L 1 --dirsfirst
.
├── config              # files needed for configuration
├── webapp              # actual webapp
├── docker-compose.yml  # docker-compose setup with container orchestration instructions
├── LICENSE             # license for this project
└── README.md           # this file

Setting up

Docker

See installation instructions at: docker documentation

Docker Compose

Install docker compose, see installation instructions at https://docs.docker.com/compose/install/

Django

Create django project in the webapp folder or copy a project to the webapp folder or use the sample project enclosed in this project and go directly to the section 'Fire it up':

# Be sure you have Django installed on your system
$ django-admin startproject <name_project>

Edit config/environment/development.env file and add the name of your project at DJANGO_PROJECT_NAME or just leave it as is to start the default application.

Edit the settings.py file with the correct database credentials and static root:

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': os.environ.get('POSTGRES_NAME'),
        'USER': os.environ.get('POSTGRES_USER'),
        'PASSWORD': os.environ.get('POSTGRES_PASSWORD'),
        'HOST': os.environ.get('POSTGRES_HOST'),
        'PORT': os.environ.get('POSTGRES_PORT'),
    }
}

STATIC_ROOT = '/srv/static-files'

Environment variables

The file config/environment/development.env contains the environment variables needed in the containers. You can edit this as you see fit, and at the moment these are the defaults that this project uses. However when you intend to use this, keep in mind that you should keep this file out of version control as it can hold sensitive information regarding your project. The file itself will contain some commentary on how a variable will be used in the container.

Fire it up

Start the container by issuing one of the following commands:

$ docker-compose up             # run in foreground
$ docker-compose up -d          # run in background

Other commands

Build images:

$ docker-compose build
$ docker-compose build --no-cache       # build without cache

See processes:

$ docker-compose ps                 # docker-compose processes
$ docker ps -a                      # docker processes (sometimes needed)
$ docker stats [container name]     # see live docker container metrics

See logs:

# See logs of all services
$ docker-compose logs

# See logs of a specific service
$ docker-compose logs -f [service_name]

Run commands in container:

# Name of service is the name you gave it in the docker-compose.yml
$ docker-compose run [service_name] /bin/bash
$ docker-compose run [service_name] python /srv/starter/manage.py shell
$ docker-compose run [service_name] env

Remove all docker containers:

docker rm $(docker ps -a -q)

Remove all docker images:

docker rmi $(docker images -q)

Some commands for managing the webapp

To initiate a command in an existing running container use the docker exec command.

# Find container_name by using docker-compose ps

# restart uwsgi in a running container.
$ docker exec [container_name] touch /etc/uwsgi/reload-uwsgi.ini

# create migration file for an app
$ docker exec -it [container-name] \
    python /srv/[project-name]/manage.py makemigrations scheduler

# migrate
$ docker exec -it [container-name] \
    python3 /srv/[project-name]/manage.py migrate

# get sql contents of a migration
$ docker exec -it [container-name] \
    python3 /srv/[project-name]/manage.py sqlmigrate [appname] 0001

# get to interactive console
$ docker exec -it [container-name] \
    python3 /srv/[project-name]/manage.py shell

# testing
docker exec [container-name] \
    python3 /srv/[project-name]/manage.py test

Troubleshooting

Q: I get the following error message when using the docker command:

FATA[0000] Get http:///var/run/docker.sock/v1.16/containers/json: dial unix /var/run/docker.sock: permission denied. Are you trying to connect to a TLS-enabled daemon without TLS? 

A: Add yourself (user) to the docker group, remember to re-log after!

$ usermod -a -G docker <your_username>
$ service docker restart

Q: Changes in my code are not being updated despite using volumes.

A: Remember to restart uWSGI for the changes to take effect.

# Find container_name by using docker-compose ps
$ docker exec [container_name] touch /etc/uwsgi/reload-uwsgi.ini