Fixtures for Mongoengine with Django not working

Question

I am using Mongoengine(version: 0.9.0 ) with Django(version: 1.8). This is my settings.py

DATABASES = {
 'default': {
   'ENGINE': 'django.db.backends.dummy'
    }
  }  
MONGO_DBNAME = "mydatabasename"
MONGO_HOSTNAME = "localhost"

connect(MONGO_DBNAME, host=MONGO_HOSTNAME)

I want to have fixtures for the application. I have created initial_data.json in myapp/fixtures/ location.

When I run the command python manage.py dumpdata , I get the following error :

CommandError: Unable to serialize database: settings.DATABASES is improperly configured. Please supply the ENGINE value. Check settings documentation for more details.

Questions:

1) Any workaround for this problem ?

2) Is there any other way to load the initial data ?

References at this link

Thank you

Answer 1

Mongoengine itsn a backend(in django terminology). Its has own models (schemas) and DOM (like ORM in docuemnt db's) but it dont have a Django backend adapters.

You can use it. But there is issue while workind with out-of-box Django solution like Tests, Fixtures, etc. You need to write your own loader, sadenly but true.

I see 2 options here:

• You can try to use Django MongoDB Engine
• You can write your own loader for mongodb

Ill write my own fixture loader for tests. I have a json file where mapped all fixture file ill need to load to db. So a fast example here:

import bson
import os
from django.conf import settings
from mongoengine.connection import get_db

def _get_db(self):
    self.db = get_db()

def _load_fixtures(self, clear_before_load=True):
    """
    Load to db a fixtures from folder fixtures/{{DB_NAME}}/{{COLLECTION_NAME}} before each test.
    In file fixtures.json mapped collection name and file name for it.
    """
    fixture_path = lambda file_name: os.path.join(settings.FIXTURES_DIR, self.db.name, file_name)
    with open(settings.COLLECTION_FIXTURES_PATH) as file_object:
        db_collections = loads(file_object.read())
        for collection_name, filename in db_collections.items():
            collection = self.db[collection_name]
            if clear_before_load:
                collection.remove()
            path = fixture_path(filename)
            if os.path.exists(path) and os.path.isfile(path):
                with open(path, 'r') as raw_data:
                    collection_data = bson.decode_all(raw_data.read())
                    for document in collection_data:
                        collection.save(document)

Answer 2

There is no support for fixtures on mongoengine, and I don't think the mongoengine team is continuing the plugin as of version 0.9.0.

What I ended up doing to load initial data for mongoDB is to create a script called startup.py in my project folder.

startup.py:

from {{app}}.models import Sample

def init():
    if Sample.objects(name="test").count() == 0: # a flag to prevent initial data repetition
        Sample(name="test").save()

Next is to run this script on Django's startup. The entry point of Django project is when DJANGO_SETTINGS_MODULE is first loaded at wsgi.py:

os.environ.setdefault("DJANGO_SETTINGS_MODULE", "{{project_name}}.settings")

import {{project_name}}.startup as startup
startup.init()

application = get_wsgi_application()

With this setup, when you run python manage.py runserver, the init() on startup.py will run and the data you set will be inserted to the DB.

Hope this helps.