# Recipe: a Python app (Flask/FastAPI/Django) on weeny

Ubuntu 24.04 with system Python. The whole trick is: don't fight PEP-668 — use a venv, and
supervise the venv's server binary by ABSOLUTE path. Works the same for a DB-backed app
(pair it with the postgres recipe).

--- Deploy ---

  # LAPTOP — build/prepare locally, then push source (respects .gitignore; venv + __pycache__ stay local)
  npx weeny-cloud push ./myapp

  # SERVER — npx weeny-cloud ssh, then:
  cd /apps/myapp
  python3 -m venv venv                       # REQUIRED: system pip is externally-managed (PEP-668);
                                             #   plain `pip3 install` errors. A venv is the clean fix.
  ./venv/bin/pip install -r requirements.txt  # include a production server: gunicorn (WSGI) or uvicorn (ASGI)

  # Supervise the venv's server by ABSOLUTE path (weeny doesn't "activate" the venv for you):
  weeny start myapp -- /apps/myapp/venv/bin/gunicorn -b 127.0.0.1:8000 -w 2 app:app
  #   FastAPI instead: -- /apps/myapp/venv/bin/uvicorn --host 127.0.0.1 --port 8000 app:app
  weeny expose myapp 8000                     # → https://myapp-xxxx.onweeny.com

--- Updating ---

  # edit locally, then:
  npx weeny-cloud push ./myapp
  #   push reinstalls deps and restarts. (A Python app usually has no build step — that's fine.)

Notes:
- requirements.txt must pin a server (gunicorn/uvicorn) and any driver (psycopg2-binary for
  postgres). node_modules-style native wheels build fine on the server.
- Bind to 127.0.0.1 only — `weeny expose` puts it on public HTTPS (TLS terminated at the edge;
  your app sees plain HTTP). Never bind 0.0.0.0 for a service you don't want public.
- Secrets/config → `weeny env myapp KEY=value` (encrypted, survives rebuilds, restarts the app).
  Read them with os.environ.
- Talking to Postgres on the same box? Connect to 127.0.0.1:5432, and open a FRESH connection
  per request (don't cache one global connection — it won't survive a Postgres restart). See
  https://app.weeny.cloud/recipes/postgres.txt