iface is not set correctly when using some examples

[dhalbert]

I'm not sure whether this is an error in the examples or in the revised legacy API.

examples/requests_simpletest.py and examples/requests_advanced.py both contain code:

# Initialize a requests object with a socket and esp32spi interface
socket.set_interface(esp)
requests.set_socket(socket)

However, this code stopped working at some point during the revision of the legacy API. If I try the simpletest, I get

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "requests_simpletest.py", line 51, in <module>
  File "adafruit_requests.py", line 636, in get
  File "adafruit_requests.py", line 535, in request
  File "adafruit_requests.py", line 420, in _get_socket
  File "adafruit_requests.py", line 604, in wrap_socket
AttributeError: 'NoneType' object has no attribute 'TLS_MODE'

Here is the relevant revised code:

class _FakeSSLContext:
    def __init__(self, iface):
        self._iface = iface

    def wrap_socket(self, socket, server_hostname=None):
        """Return the same socket"""
        # pylint: disable=unused-argument
        return _FakeSSLSocket(socket, self._iface.TLS_MODE)

def set_socket(sock, iface=None):
    """Legacy API for setting the socket and network interface. Use a `Session` instead."""
    global _default_session  # pylint: disable=global-statement,invalid-name
    _default_session = Session(sock, _FakeSSLContext(iface))
    if iface:
        sock.set_interface(iface)

The _FakeSSLContext ends up with a None iface, and then wrap_socket() fails because self._iface.TLS_MODE will fail.

[makermelissa]

If you use requests.set_socket(socket, esp) like the PyPortal library does, it should work correctly. Maybe the examples just need to be updated?

[dhalbert]

I think that's true, but maybe the examples used to work (by accident??) The old code is this:

class _FakeSSLContext:
    @staticmethod
    def wrap_socket(socket, server_hostname=None):
        """Return the same socket"""
        # pylint: disable=unused-argument
        return socket

def set_socket(sock, iface=None):
    """Legacy API for setting the socket and network interface. Use a `Session` instead."""
    global _default_session # pylint: disable=global-statement,invalid-name
    _default_session = Session(sock, _FakeSSLContext())
    if iface:
        sock.set_interface(iface)

wrap_socket() doesn't use the iface, so it won't have an error.

[dhalbert]

Is the socket.set_interface() just unnecessary if you do requests.set_socket(socket, esp)? I am just not familiar with the idioms for using the library.

[makermelissa]

Hmm, perplexing. 🤔

[dhalbert]

It does work to replace the two lines with the one. (The point of all this was just to test that the revised requests library still worked on AirLift with SSL.)

[anecdata]

Here's what I do:, and it works in CircuitPython. There may be a different sequence to be fully compatible with CPython:

# SP32-S2:

    pool = socketpool.SocketPool(wifi.radio)
    requests = adafruit_requests.Session(pool, ssl.create_default_context())

# ESP32SPI:

    # Requests (legacy API)
    requests.set_socket(socket, esp)

I don't know of a single code sequence that works in CircuitPython on both non-ESP32-S2 and ESP32-S2. The Requests import is typically different between the two also. I suspect Scott is aiming for CPython compatibility on all platforms as he reworks the legacy stack.

[tannewt]

@dhalbert I think the simplest thing is to have set_socket pull the interface from the socket if it isn't provided. It's all a hack for backwards compatibility so we can do sketchy things in it.