Setting up a Postgres DB for Django with Fly.io

Question

I'm a novice trying to spin up my first webapp with a combination of Fly.io, Django, and a postgres DB but I'm having some trouble and can't find an answer in walkthroughs or Q&A.

I've set up a simple "Hello world" Django app (models.py is empty so far) and I'm trying to get all the components up and running before I build it out any further.

I've successfully deployed my app on Fly.io with no errors
I've created a postgres cluster on Fly.io using the instructions here: https://fly.io/docs/postgres/
I've attached the cluster to my app, which generates a DB and sets an environment variable with the appropriate details (username, password, port, host, dbname)

I've updated my settings.py file:

DATABASES = {}
DATABASES["default"] = dj_database_url.config(conn_max_age=600, ssl_require=True)

I've added to my fly.toml:

[[services]]
  internal_port = 5432 # Postgres instance
  protocol = "tcp"

# Open port 10000 for plaintext connections.
[[services.ports]]
  handlers = []
  port = 10000

I've confirmed I can get into the psql shell with flyctl postgres connect -a MYAPP-pg

But unfortunately when I run python manage.py migrate to check that everything is working, I get the following error:

File "<my_path>\venv\lib\site-packages\django\db\backends\base\base.py", line 282, in ensure_connection
 self.connect()
File "<my_path>\venv\lib\site-packages\django\utils\asyncio.py", line 26, in inner
 return func(*args, **kwargs)
File "<my_path>\venv\lib\site-packages\django\db\backends\base\base.py", line 263, in connect
 self.connection = self.get_new_connection(conn_params)
File "<my_path>\venv\lib\site-packages\django\utils\asyncio.py", line 26, in inner
 return func(*args, **kwargs)
File "<my_path>\venv\lib\site-packages\django\db\backends\postgresql\base.py", line 215, in get_new_connection
 connection = Database.connect(**conn_params)
File "<my_path>\venv\lib\site-packages\psycopg2\__init__.py", line 122, in connect
 conn = _connect(dsn, connection_factory=connection_factory, **kwasync)
psycopg2.OperationalError: could not translate host name "top2.nearest.of.MYAPP-pg.internal" to address: Unknown host

Any ideas what might be happening? Any help would be very much appreciated!

It sounds like your app is deployed outside of the network that your postgres instance is hosted on. Your hostname `top2.nearest.of.MYAPP-pg.internal` looks like an internal hostname, meaning your app should also be deployed within the same network. If you need to expose your postgres instance to outside applications, I think their docs mentioned using WireGuard to port forward the instance to your local machine: https://fly.io/docs/postgres/#connecting-to-fly-postgres-from-outside-fly — Scratch'N'Purr, Oct 24 '22 at 21:11

Setting up a Postgres DB for Django with Fly.io

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