Specifying Readonly access for Django.db connection object

Question

I have a series of integration-level tests that are being run as a management command in my Django project. These tests are verifying the integrity of a large amount of weather data ingested from external sources into my database. Because I have such a large amount of data, I really have to test against my production database for the tests to be meaningful. What I'm trying to figure out is how I can define a read-only database connection that is specific to that command or connection object. I should also add that these tests can't go through the ORM, so I need to execute raw SQL.

The structure of my test looks like this

class Command(BaseCommand):
    help = 'Runs Integration Tests and Query Tests against Prod Database'

    def handle(self,*args, **options):
        suite = unittest.TestLoader().loadTestsFromTestCase(TestWeatherModel)
        ret = unittest.TextTestRunner().run(suite)
        if(len(ret.failures) != 0):
            sys.exit(1)
        else:
            sys.exit(0)

class TestWeatherModel(unittest.TestCase):
    def testCollectWeatherDataHist(self):
        wm = WeatherManager()
        wm.CollectWeatherData()
        self.assertTrue(wm.weatherData is not None)

And the WeatherManager.CollectWeatherData() method would look like this:

def CollecWeatherData(self):
    cur = connection.cursor()
    cur.execute(<Raw SQL Query>)
    wm.WeatherData = cur.fetchall()
    cur.close()

I want to somehow idiot-proof this, so that someone else (or me) can't come along later and accidentally write a test that would modify the production database.

Answer 1

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.postgresql_psycopg2',
        'NAME': 'mydb',
        'USER': 'myusername',
        'PASSWORD': 'mypassword',
        'HOST': 'myhost',
        'OPTIONS': {
            'options': '-c default_transaction_read_only=on'
        }
    }
}

Source: https://nejc.saje.info/django-postgresql-readonly.html