Montréal-Django

Django development using

December 1, 2015

Welcome

Daniel LeBlanc

CEO at ctrlweb

@danidou

https://ca.linkedin.com/in/dleblanc78

YulDev Organizer

Montréal-Django Organizer

Symfony Montréal Co-organizer

Laravel Montréal Co-organizer

daniel@ctrlweb.ca

Job Offers

Job Seekers

invite.yuldev.ca

Tonight's Objectives

Learn the basic principles behind Docker

Learn a few neat tricks to build a working Django dev environment

And that's about it!

This is an

introductory

talk

Glossary

Docker Engine

Creates and runs Docker containers.

Runtime instance of a
Docker image.

Docker Container

Docker image

"Recipe" to build a container. Stateless and never changes. Shared via the Docker Hub.

Docker Hub

Hosted registry service for managing images. The "GitHub" of Docker images.

Base image

Parentless images. Docker images can "extend" other Docker images.

Docker Compose

Defines multi-container applications.

What is Docker?

Docker allows you to package an application with all of its dependencies into a standardized unit for software development.

- Docker website

Architecture

But why?

Hacking like a pro on your machine

thinking: "Docker is for n00bz!"

And then you deploy

on another machine...

WORKS ON MY MACHINE!

Here are a few good
reasons to use Docker:

  1. Gives you consistency between environments
  2. Speeds up environment setup & deployments
  3. Allows you to share your projects, environment included
  4. Allows you to build portable and scalable solutions
  5. Gives you environment versioning
  6. ... and much, much more!

Do you know what Vagrant is?

Nope

Yup

Do you use it to build Django apps?

Nope

Yup

(a side adventure!)

VS

Vagrant VMs

Docker containers

Vagrant VMs

Containers

Large

Small

Size (drive space)

Startup speed

Fast

Slow

Interaction

Very easy

Complicated

Memory footprint

Tiny

Large

Versioning

Each container

Whole VM

Vagrant is not bad!

It's just a different tool altogether!

It can be very useful!

http://tinyurl.com/docker-vs-vagrant

In fact...

From the author of Docker:

If you want to manage machines, you should use Vagrant. And if you want to build and run applications environments, you should use Docker.

All right, then. Let's move on!

Let's

Yup

A few basic commands

$ docker search ubuntu
NAME       DESCRIPTION                                     STARS     OFFICIAL   AUTOMATED
ubuntu     Ubuntu is a Debian-based Linux operating s...   2729      [OK]¶
[...]
$ docker pull ubuntu
Using default tag: latest
latest: Pulling from library/ubuntu
2332d8973c93: Downloading [=================>              ] 23.25 MB/65.67 MB
ea358092da77: Download complete
[...]

Search for an image in Docker Hub

Create a container from a Docker Image

$ docker run -it ubuntu /bin/bash
root@c2bb2bc1e0e8:/#

Run a command within a container

Docker (engine)

$ docker-compose build
db uses an image, skipping
Building app...
Step 0 : FROM python:3.3
 ---> d6f2c2d52f99
[...]
$ docker-compose ps
     Name                    Command                State     Ports
-------------------------------------------------------------------
ctrlwebca_app_1   python3 manage.py runserve ...   Exit 137
ctrlwebca_db_1    /docker-entrypoint.sh postgres   Exit 0

Build an application's containers

List an application's containers

$ docker-compose up -d
Starting ctrlwebca_db_1...
Starting ctrlwebca_app_1...

Create and start an application's containers

Docker Compose

Recipe time!

Recipe #1

A micro PaaS server

autodock:
  image: prologic/autodock
  restart: always
  ports:
    - "1338:1338/udp"
    - "1338:1338/tcp"
  volumes:
    - /var/run/docker.sock:/var/run/docker.sock

autodocklogger:
  image: prologic/autodock-logger
  restart: always
  links:
    - autodock

autodockhipache:
  image: prologic/autodock-hipache
  restart: always
  links:
    - autodock
    - hipache:redis

hipache:
  image: tutum/hipache
  restart: always
  ports:
    - 80:80
    - 443:443

< Docker automation daemon 

< Docker events logger 

< Automatic Hipache VirtualHost

< Distributed HTTP & WS proxy

Step 1: Create a Docker Compose file

$ docker-compose up -d

Step 2: Run it

And that's it! You have a micro PaaS server running on your machine!

Recipe #2

A working Django application

Step 1: Create a Dockerfile

FROM python:3.3

ENV PYTHONBUFFERED 1
ENV APPLICATION_ROOT /code

RUN mkdir -p $APPLICATION_ROOT
WORKDIR $APPLICATION_ROOT
ADD requirements.txt $APPLICATION_ROOT/
RUN pip install -r requirements.txt
ADD . $APPLICATION_ROOT/

Dockerfile

Step 2: Create a requirements file

Django
psycopg2

requirements.txt

Step 3: Create a Docker Compose file

app:
  build: .
  expose:
    - "80"
  links:
    - db
  volumes:
    - .:/code
  command: python3 manage.py runserver 0.0.0.0:80
  environment:
    VIRTUALHOST: montreal-django.local
db:
  image: postgres

docker-compose.yml

Step 4: Setup a Django project

$ docker-compose run app django-admin.py startproject tutorial .
Starting dockertutorial_db_1...

Step 5: Configure your DB

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'postgres',
        'USER': 'postgres',
        'HOST': 'db',
        'PORT': 5432,
    }
}

Step 6: Run it

$ docker-compose up -d
Starting dockertutorial_db_1...
Starting dockertutorial_app_1...

montreal-django.local

Also, just so you know...

You can use Docker to...

  • run multiple applications on a single node
     
  • run a single application on multiple clustered nodes (via Swarm)

tutum

currently in free beta

https://dashboard.tutum.co/

Merci!

Thank you!

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