Lifespan

You can register lifespan handlers to run code before the app starts, or after it shuts down. This ideal for setting up and tearing down database connections or machine learning models for instance.

AsyncApp

import contextlib
import typing

from connexion import AsyncApp, ConnexionMiddleware, request

@contextlib.asynccontextmanager
def lifespan_handler(app: ConnexionMiddleware) -> typing.AsyncIterator:
    """Called at startup and shutdown, can yield state which will be available on the
     request."""
    client = Client()
    yield {"client": client}
    client.close()

def route():
    """Endpoint function called when receiving a request, you can access the state
    on the request here."""
    client = request.state.client
    client.call()

app = AsyncApp(__name__, lifespan=lifespan_handler)

FlaskApp

import contextlib
import typing

from connexion import FlaskApp, ConnexionMiddleware, request

@contextlib.asynccontextmanager
def lifespan_handler(app: ConnexionMiddleware) -> typing.AsyncIterator:
    """Called at startup and shutdown, can yield state which will be available on the
     request."""
    client = Client()
    yield {"client": client}
    client.close()

def route():
    """Endpoint function called when receiving a request, you can access the state
    on the request here."""
    client = request.state.client
    client.call()

app = FlaskApp(__name__, lifespan=lifespan_handler)

ConnexionMiddleware

import contextlib
import typing

from asgi_framework import App
from connexion import ConnexionMiddleware, request

@contextlib.asynccontextmanager
def lifespan_handler(app: ConnexionMiddleware) -> typing.AsyncIterator:
    """Called at startup and shutdown, can yield state which will be available on the
     request."""
    client = Client()
    yield {"client": client}
    client.close()

def endpoint():
    """Endpoint function called when receiving a request, you can access the state
    on the request here."""
    client = request.state.client
    client.call()

app = App(__name__)
app = ConnexionMiddleware(app, lifespan=lifespan_handler)

Running lifespan in tests

If you want lifespan handlers to be called during tests, you can use the test_client as a context manager.

def test_homepage():
    app = ...  # Set up app
    with app.test_client() as client:
        # Application's lifespan is called on entering the block.
        response = client.get("/")
        assert response.status_code == 200

    # And the lifespan's teardown is run when exiting the block.

For more information, please refer to the Starlette documentation.