Hello, wellcome to the project:

Django as microservice with RabbitMq and Nameko

What is it about?

This is a tutorial for usage of Django framework running microservices with RabbitMq as message broker, using the python framework for building microservices Nameko

The goal of this tutorial is to show how you can use Django, it's ORM (Object-Relational Mapper) and all Django features to develop microservices capable of communicate via AMQP (Advanced Message Queuing Protocol) with RabbitMq through RPC (remote procedure call) and Events call (pub-sub) using Nameko framework

This project is motivated by the benefits of a microservice communicating using AMQP, you can read more in this nginx article

---

Tutorial

For this tutorial you must have installed django, nameko and docker

$ pip install Django
$ pip install nameko
$ pip install docker

Create a django project

$ django-admin startproject book_microservice

Create a django app

$ cd book_microservice
$ django-admin startapp book

Insert you app on INSTALLED_APPS in book_microservice/settings.py

INSTALLED_APPS = [
'django.contrib.admin',
...
'django.contrib.staticfiles',
'book',
]

In book/models.py

from django.db import models

class Book(models.Model):
title = models.TextField(max_length=250)
author = models.TextField(max_length=250)

Save your model and run

$ python manage.py makemigrations
$ python manage.py migrate

In book/views.py

from nameko.rpc import rpc
from book.models import Book

class DjangoService(object):
name = "book_service"

@rpc
def first_book(self):
return Book.objects.first().title

@rpc
def last_book(self):
return Book.objects.last().title

@rpc
def save_book(self, title, author):
book = Book()
book.title = title
book.author = author
book.save()

Now, in the same directory as manage.py, create a file with name run_services.py

import os
import django
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "book_microservice.settings")
django.setup()

from book.views import DjangoService

Running a RabbitMq instance

The easiest way to run RabbitMq is using docker with this command:

$ docker run -d --hostname my-rabbit --name some-rabbit -p 15672:15672 -p 5672:5672 rabbitmq:3-management

Running the microservice

Now you can launch your services using

$ nameko run run_services --broker amqp://guest:guest@localhost

Your console must look like

starting services: book_service
Connected to amqp://guest:**@127.0.0.1:5672//

In another terminal you can run a nameko shell to run the rpc's of your microservices

$ nameko shell

n.rpc.book_service.save_book('title1','author1')
book = n.rpc.book_service.first_book()
print(book)

out: 'title1'

this nameko shell shows how you can make a rpc call over the amqp, wich can also be done by another python aplication, as an API, using Nameko

Tests

You can unit test your view in book/test

from django.test import TestCase
from .models import Book
from .views import DjangoService

class ServiceTestCase(TestCase):
def setUp(self):
Book.objects.create(title='title_test', author='author_test')

def test_first_book(self):
book = Book.objects.first()
self.assertEqual(DjangoService.first_book(self), book.title)

def test_save_book(self):
title = 'title_test2'
author = 'author_test2'
DjangoService.save_book(self, title, author)
book = Book.objects.get(title=title, author=author)
self.assertEqual(book.title, title)
self.assertEqual(book.author, author)

and run

python manage.py test

out:
Ran 2 tests in 0.006s
OK

notes

If you wish to send your data as json, you can use djangorestframework's serializer.

Read more about RPC and Events (pub-sub) in this nameko documentation