What is Polaris?¶
Polaris is an extendable django app for Stellar Ecosystem Proposal (SEP) implementations maintained by the Stellar Development Foundation (SDF). Using Polaris, you can run a web server supporting any combination of SEP-1, 6, 10, 12, 24, and 31.
While Polaris handles the majority of the business logic described in each SEP, there are pieces of functionality that can only be implemented by the developer using Polaris. For example, only an anchor can implement the integration with their partner bank.
This is why each SEP implemented by Polaris comes with a programmable interface, or integration points, for developers to inject their own business logic.
The instructions below outline the common set up needed for any Polaris deployment, but each SEP implementation has its own configuration and integration requirements. These requirements are described in the documentation for each SEP.
Installation and Configuration¶
These instructions assume you have already set up a django project. If you haven’t, take a look at the Django docs.
First make sure you have
cd’ed into your django project’s main directory
and then run
pip install django-polaris
Add the following to
INSTALLED_APPS in settings.py.
INSTALLED_APPS = [ ..., "corsheaders", "rest_framework", "polaris", ]
CorsMiddleware to your
settings.MIDDLEWARE. It should be listed above
other middleware that can return responses such as
MIDDLEWARE = [ ..., 'corsheaders.middleware.CorsMiddleware', ... ]
Polaris will now accept requests from all origins to its endpoints. It does this by adding corsheaders signal that checks the request URI. However this does not change the CORS policy for any other endpoint on the server. You can change this functionality using the settings listed in the corsheaders documentation.
PROJECT_ROOT in your project’s settings.py. Polaris uses this to
PROJECT_ROOT = "<path to directory containing .env file>"
Polaris uses environment variables that should be defined in the
environment or included in
STELLAR_NETWORK_PASSPHRASE="Test SDF Network ; September 2015" HORIZON_URI="https://horizon-testnet.stellar.org/" HOST_URL="https://example.com"
Add the Polaris endpoints in
import polaris.urls from django.urls import path, include urlpatterns = [ ..., path("", include(polaris.urls)), ]
SEP-1, 6, and 24 require Polaris’ database models. Polaris currently only supports PostgreSQL and uses psycopg2 to connect to the database. If you use another database, file an issue in the project’s github repository.
Run migrations to create these tables in your database.
python manage.py migrate
Now, create an
Asset database object for each asset you intend to anchor. Get
into your python shell, then run something like this:
from polaris.models import Asset Asset.objects.create( code="USD", issuer="<the issuer address>", distribution_seed="<distribution account secret key>", significant_digits=2, deposit_fee_fixed=1, deposit_fee_percent=2, withdraw_fee_fixed=1, withdraw_fee_percent=2, deposit_min_amount=10, deposit_max_amount=10000, withdrawal_min_amount=10, withdrawal_min_amount=10000, sep24_enabled=True, sep6_enabled=True )
distribution_seed column is encrypted at the database layer using Fernet symmetric
encryption, and only decrypted when held in memory within an
Asset object. It uses
your Django project’s
SECRET_KEY setting to generate the encryption key, so make sure
its value is unguessable and kept a secret.
See the Asset documentation for more information on the fields used.
At this point, you should configure Polaris for one or more of the SEPs currently supported. Once configured, check out how to run the server as described in the next section.
Running the Web Server¶
Polaris should only be deployed using HTTPS in production. You should do this by using a HTTPS web server or running Polaris behind a HTTPS reverse proxy. The steps below outline the settings necessary to ensure your deployment is secure.
To redirect HTTP traffic to HTTPS, add the following to settings.py:
SECURE_SSL_REDIRECT = True
And if you’re running Polaris behind a HTTPS proxy:
SECURE_PROXY_SSL_HEADER = ('HTTP_X_FORWARDED_PROTO', 'https')
This tells Django what header to check and what value it should be in order to consider the incoming request secure.
Locally, Polaris can be run using Django’s HTTP development server
python manage.py runserver
If you’re using Polaris’ SEP-24 support, you also need to use the following environment variable:
This is necessary to disable SEP-24’s interactive flow authentication mechanism, which requires HTTPS. Do not use local mode in production.
To set up the development environment or run the SDF’s reference server, run follow the instructions below.
git clone email@example.com:stellar/django-polaris.git cd django-polaris
Then, add a
.env file in the
example directory. You’ll need to create
a signing account on Stellar’s testnet and add it to your environment variables.
DJANGO_SECRET_KEY="supersecretdjangokey" DJANGO_DEBUG=True SIGNING_SEED=<your signing account seed> STELLAR_NETWORK_PASSPHRASE="Test SDF Network ; September 2015" HORIZON_URI="https://horizon-testnet.stellar.org/" SERVER_JWT_KEY="your jwt local secret" DJANGO_ALLOWED_HOSTS=localhost,0.0.0.0,127.0.0.1 HOST_URL="http://localhost:8000" LOCAL_MODE=True
Next, you’ll need to create an asset on the Stellar test network and setup a distribution account. See this tool for creating assets on testnet.
Now you’re ready to add your asset to Polaris. Run the following commands:
$ docker-compose build $ docker-compose up server
Go to http://localhost:8000/admin and login with the default credentials (root, password).
Go to the Assets menu, and click “Add Asset”
Enter the code, issuer, and distribution seed for the asset. Make sure that the asset is enabled for SEP-24 and SEP-6 by selecting the Deposit Enabled, Withdrawal Enabled, and either both or one of Sep24 Enabled and Sep6 Enabled.
Finally, kill the current
docker-compose process and run a new one:
$ docker-compose up
You should now have a anchor server running SEP 6 & 24 on port 8000. When you make changes locally, the docker containers will restart with the updated code.
You can install the dependencies locally in a virtual environment:
pip install pipenv cd django-polaris pipenv install --dev pipenv run pytest -c polaris/pytest.ini
Or, you can simply run the tests from inside the docker container. However, this may be slower.
docker exec -it server pytest -c polaris/pytest.ini
Submit a PR¶
After you’ve made your changes, push them to you a remote branch and make a Pull Request on the stellar/django-polaris master branch.