Making django dev server with docker

I’m trying to use docker when deploying for this django project. Docker is useful for deploying server, but I try to use docker for dev environment server for some reason:

• get familiar with docker
• easy to manage dev environment for all team members
• hard to manage many python environment in local (althoug use pyenv or virtualenv, it’s always confusing)

So I made dev server with docker

Precedence knowledge

If you are first time in docker, this example is little bit difficult to follow. you might have

• basic knowledge about docker image and container
• how to run docker image
• basic useage about github (clone)

Try with docker image and container

Get example source code

You can get example source code from my github this page.

$ git clone https://github.com/bartkim0426/django-dev-with-docker .

Build image from local

Create image from example code source. When using docker build <path>, it will automatically build image from Dockerfile

$docker build -t django-dev .

-t option is for tag. you can build image with your own tag.

Run postgres container

you shold run postgres server for dev db. it’s easy with postgres official image from docker hub

docker run -it --rm \
	--name postgres \
	-e POSTGRES_DB=djangodev \
	-e POSTGRES_USER=exampleuser \
	-e POSTGRES_PASSWORD=examplepassword \
	--volume=$(pwd)/docker/data:/var/lib/postgresql/data \
	postgres:9.6.3

• with --rm option, docker automatically remove container when container stop
• with -e option, you can give environ variables
• with --volume, you can keep data beside docker container: postgres is db so you should protect data from auto-deleting

Run django container

docker run -it --rm \
	-p 8000:8000 \
	--link postgres \
	-e DJANGO_DB_HOST=postgres \
	-e DJANGO_DEBUG=True \
	--volume=$(pwd):/app/ \
	django-dev \
	./manage.py runserver 0.0.0.0:8000

• with --link option, you can connect django-dev container to postgres container
• with --volume, you can keep your source code seperately

After all this, you can access dev server with localhost:8000!

Using docker-compose

With about approach, there’s many limit

• it’s really difficult to type all docker run options
• have to start two container with order: postgres => django

When using docker-compose, you can create and start many container at once, with docker-compose.yml

version: '2.1'

volumes:
  django_sample_db_dev: {}
  django_sample_packages: {}

services:
  db:
    image: postgres:9.6.1
    volumes:
      - django_sample_db_dev:/var/lib/postgresql/data
    environment:
      - POSTGRES_DB=sampledb
      - POSTGRES_USER=sampleuser
      - POSTGRES_PASSWORD=samplesecret
      - POSTGRES_INITDB_ARGS=--encoding=UTF-8
    healthcheck:
      test: "pg_isready -h localhost -p 5432 -U postgres"
      interval: 3s
      timeout: 1s
      retries: 10

  django:
    build:
      context: .
      dockerfile: ./compose/django/Dockerfile-dev
    environment:
      - DJANGO_DEBUG=True
      - DJANGO_DB_HOST=postgres
      - DJANGO_DB_PORT=5432
      - DJANGO_DB_NAME=sampledb
      - DJANGO_DB_USERNAME=sampleuser
      - DJANGO_DB_PASSWORD=samplesecret
      - DJANGO_SECRET_KEY=dev_secret_key
    ports:
      - "8000:8000"
    depends_on:
      db:
        condition: service_healthy
    links:
      - db:postgres
    command: /start-dev.sh
    volumes:
      - ./manage.py:/app/manage.py
      - ./requirements.txt:/app/requirements.txt
      - ./djangosample:/app/djangosample
      - django_sample_packages:/usr/local/lib/python3.6/site-packages/