DATABASES = { 'default': { 'ENGINE': 'django.db.backends.postgresql', 'NAME': 'db_name', 'USER': 'db_user', 'PASSWORD': 'db_user_password', 'HOST': '', 'PORT': 'db_port_number', }
}

# Just after the default DATABASE configuration add this in settings.py
POSTGRES_DB = os.environ.get("POSTGRES_DB")
POSTGRES_PASSWORD = os.environ.get("POSTGRES_PASSWORD")
POSTGRES_USER = os.environ.get("POSTGRES_USER")
POSTGRES_HOST = os.environ.get("POSTGRES_HOST")
POSTGRES_PORT = os.environ.get("POSTGRES_PORT")
POSTGRES_READY = ( POSTGRES_DB is not None and POSTGRES_PASSWORD is not None and POSTGRES_USER is not None and POSTGRES_HOST is not None and POSTGRES_PORT is not None
)
if POSTGRES_READY: DATABASES = { "default": { "ENGINE": "django.db.backends.postgresql", "NAME": POSTGRES_DB, "USER": POSTGRES_USER, "PASSWORD": POSTGRES_PASSWORD, "HOST": POSTGRES_HOST, "PORT": POSTGRES_PORT, } }