bernardopires / django-tenant-schemas

Tenant support for Django using PostgreSQL schemas.
https://django-tenant-schemas.readthedocs.org/en/latest/
MIT License
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django-tenant-schemas

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This application enables django powered websites to have multiple tenants via PostgreSQL schemas. A vital feature for every Software-as-a-Service website.

Django provides currently no simple way to support multiple tenants using the same project instance, even when only the data is different. Because we don't want you running many copies of your project, you'll be able to have:

What are schemas

A schema can be seen as a directory in an operating system, each directory (schema) with it's own set of files (tables and objects). This allows the same table name and objects to be used in different schemas without conflict. For an accurate description on schemas, see PostgreSQL's official documentation on schemas_.

Why schemas

There are typically three solutions for solving the multitenancy problem.

  1. Isolated Approach: Separate Databases. Each tenant has it's own database.

  2. Semi Isolated Approach: Shared Database, Separate Schemas. One database for all tenants, but one schema per tenant.

  3. Shared Approach: Shared Database, Shared Schema. All tenants share the same database and schema. There is a main tenant-table, where all other tables have a foreign key pointing to.

This application implements the second approach, which in our opinion, represents the ideal compromise between simplicity and performance.

Each solution has it's up and down sides, for a more in-depth discussion, see Microsoft's excellent article on Multi-Tenant Data Architecture_.

How it works

Tenants are identified via their host name (i.e tenant.domain.com). This information is stored on a table on the public schema. Whenever a request is made, the host name is used to match a tenant in the database. If there's a match, the search path is updated to use this tenant's schema. So from now on all queries will take place at the tenant's schema. For example, suppose you have a tenant customer at http://customer.example.com. Any request incoming at customer.example.com will automatically use customer\ 's schema and make the tenant available at the request. If no tenant is found, a 404 error is raised. This also means you should have a tenant for your main domain, typically using the public schema. For more information please read the setup_ section.

What can this app do?

As many tenants as you want


Each tenant has its data on a specific schema. Use a single project
instance to serve as many as you want.

Tenant-specific and shared apps

Tenant-specific apps do not share their data between tenants, but you can also have shared apps where the information is always available and shared between all.

Tenant View-Routing


You can have different views for ``http://customer.example.com/`` and
``http://example.com/``, even though Django only uses the string after
the host name to identify which view to serve.

Magic

Everyone loves magic! You'll be able to have all this barely having to change your code!

Setup & Documentation

This is just a short setup guide, it is strongly recommended that you read the complete version at django-tenant-schemas.readthedocs.io_.

Your DATABASE_ENGINE setting needs to be changed to

.. code-block:: python

DATABASES = {
    'default': {
        'ENGINE': 'tenant_schemas.postgresql_backend',
        # ..
    }
}

Add the middleware tenant_schemas.middleware.TenantMiddleware to the top of MIDDLEWARE_CLASSES, so that each request can be set to use the correct schema.

.. code-block:: python

MIDDLEWARE_CLASSES = (
    'tenant_schemas.middleware.TenantMiddleware',
    #...
)

Add tenant_schemas.routers.TenantSyncRouter to your DATABASE_ROUTERS setting, so that the correct apps can be synced, depending on what's being synced (shared or tenant).

.. code-block:: python

DATABASE_ROUTERS = (
    'tenant_schemas.routers.TenantSyncRouter',
)

Add tenant_schemas to your INSTALLED_APPS.

Create your tenant model



.. code-block:: python

    from django.db import models
    from tenant_schemas.models import TenantMixin

    class Client(TenantMixin):
        name = models.CharField(max_length=100)
        paid_until =  models.DateField()
        on_trial = models.BooleanField()
        created_on = models.DateField(auto_now_add=True)

Define on ``settings.py`` which model is your tenant model. Assuming you
created ``Client`` inside an app named ``customers``, your
``TENANT_MODEL`` should look like this:

.. code-block:: python

    TENANT_MODEL = "customers.Client" # app.Model

Now run ``migrate_schemas`` to sync your apps to the ``public`` schema.

::

    python manage.py migrate_schemas --shared

Create your tenants just like a normal django model. Calling ``save``
will automatically create and sync/migrate the schema.

.. code-block:: python

    from customers.models import Client

    # create your public tenant
    tenant = Client(domain_url='tenant.my-domain.com',
                    schema_name='tenant1',
                    name='My First Tenant',
                    paid_until='2014-12-05',
                    on_trial=True)
    tenant.save()

Any request made to ``tenant.my-domain.com`` will now automatically set
your PostgreSQL's ``search_path`` to ``tenant1`` and ``public``, making
shared apps available too. This means that any call to the methods
``filter``, ``get``, ``save``, ``delete`` or any other function
involving a database connection will now be done at the tenant's schema,
so you shouldn't need to change anything at your views.

You're all set, but we have left key details outside of this short
tutorial, such as creating the public tenant and configuring shared and
tenant specific apps. Complete instructions can be found at
`django-tenant-schemas.readthedocs.io`_.

.. _django: https://www.djangoproject.com/
.. _PostgreSQL schemas: http://www.postgresql.org/docs/9.1/static/ddl-schemas.html
.. _PostgreSQL's official documentation on schemas: http://www.postgresql.org/docs/9.1/static/ddl-schemas.html
.. _Multi-Tenant Data Architecture: https://web.archive.org/web/20170530080303/https://msdn.microsoft.com/en-us/library/aa479086.aspx

.. |PyPi version| image:: https://img.shields.io/pypi/v/django-tenant-schemas.svg
   :target: https://pypi.python.org/pypi/django-tenant-schemas
.. |PyPi downloads| image:: https://img.shields.io/pypi/dm/django-tenant-schemas.svg
   :target: https://pypi.python.org/pypi/django-tenant-schemas
.. |Python versions| image:: https://img.shields.io/pypi/pyversions/django-tenant-schemas.svg
.. |Travis CI| image:: https://travis-ci.org/bernardopires/django-tenant-schemas.svg?branch=master
   :target: https://travis-ci.org/bernardopires/django-tenant-schemas
.. |PostgreSQL| image:: https://img.shields.io/badge/PostgreSQL-9.2%2C%209.3%2C%209.4%2C%209.5%2C%209.6-blue.svg
.. _setup: https://django-tenant-schemas.readthedocs.io/en/latest/install.html
.. _django-tenant-schemas.readthedocs.io: https://django-tenant-schemas.readthedocs.io/en/latest/