Opinionated Service Discovery for Django
========================================
This project provides a simple workflow for registering services in Django. It is highly opinionated and makes a lot
of assumptions.
Goal
----
When developing a Django application, you often need external services such as a database, a key-value store, a
message broker, etc. etc. I prefer to use `Docker <https://www.docker.com/whatisdocker>`_ and
`Docker-Compose <https://docs.docker.com/compose/>`_ to have those services running when I develop my application.
``django-discovery`` makes it easy to connect to those services, as long as you follow a specific workflow:
- Development is done on your own machine, with the services running under Docker;
- Testing is done by running both the services and the application using Docker Compose;
- The production environment provides an SRV-lookup capable DNS. Examples are:
+ Running everything under `Kubernetes <http://kubernetes.io>`_
+ Running everything on Docker, configured to use an SRV-capable DNS such as `Consul <http://www.consul.io>`_
Requirements
------------
``django-discovery`` requires Python 3 and Django 1.8 because we live in modern times.
Quickstart
----------
The following example assumes a Django application that requires a MySQL database. Add the following to your
``settings.py``:
::
from discovery import services
db = services.register('my_db', 'mysql', secrets=['mysql_user', 'mysql_database', 'mysql_password'])
DATABASES = {
'default': {
'ENGINE': 'django.db.backends.mysql',
'NAME': db.secrets['mysql_database'],
'USER': db.secrets['mysql_user'],
'PASSWORD': db.secrets['mysql_password'],
'HOST': db.host,
'PORT': db.port,
}
}
DEBUG = services.debug_mode
You can now run your application on localhost with your database under docker using the following
``docker-compose.yml``:
::
my_db:
image: mysql:5.6
ports:
- ":3306"
environment:
MYSQL_ROOT_PASSWORD: supersecret
MYSQL_DATABASE: database_name
MYSQL_USER: database_user
MYSQL_PASSWORD: alsosecret
You can also run your application in its entirety in docker, using for example the following docker-compose file:
::
database:
image: mysql:5.6
environment:
MYSQL_ROOT_PASSWORD: supersecret
MYSQL_DATABASE: database_name
MYSQL_USER: database_user
MYSQL_PASSWORD: alsosecret
application:
build: .
links:
- database:my_db
ports:
- "80:8080"
env:
DISCOVERY_MODE: env
And still using the same ``settings.py``, you can even run your application under Kubernetes using the following
definitions:
::
apiVersion: v1
kind: Service
metadata:
name: my_db
spec:
ports:
- protocol: tcp
port: 3306
::
apiVersion: v1
kind: Endpoints
metadata:
name: my_db
subsets:
- addresses:
- ip: 1.2.3.4
- ports:
- port: 3306
::
apiVersion: v1
kind: Pod
metadata:
name: my_application
namespace: my_namespace
spec:
containers:
- name: my_application
image: my/docker-image
volumeMounts:
- name: db_secrets
mountPath: /etc/secrets/my_db
readOnly: true
volumes:
- name: db_secrets
secret:
mysql_database: some_name
mysql_user: some_user
mysql_password: secret_password
Full Documentation
------------------
Working on it...
License
-------
This project is licensed under the MIT license.
